Trichome diversity in the Vernonieae (Asteraceae) of Mexico I: Vernonanthura and Vernonia (Vernoniinae) Author(s): Rosario Redonda-Martínez, José Luis Villaseñor, and Teresa Terrazas Source: The Journal of the Torrey Botanical Society, 139(3):235-247. 2012. Published By: Torrey Botanical Society URL: http://www.bioone.org/doi/full/10.3159/TORREY-D-11-00069.1 BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in the biological, ecological, and environmental sciences. BioOne provides a sustainable online platform for over 170 journals and books published by nonprofit societies, associations, museums, institutions, and presses. Your use of this PDF, the BioOne Web site, and all posted and associated content indicates your acceptance of BioOne’s Terms of Use, available at www.bioone.org/page/ terms_of_use. Usage of BioOne content is strictly limited to personal, educational, and non-commercial use. Commercial inquiries or rights and permissions requests should be directed to the individual publisher as copyright holder. BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research. Journal of the Torrey Botanical Society 139(3), 2012, pp. 235–247 Trichome diversity in the Vernonieae (Asteraceae) of Mexico I: Vernonanthura and Vernonia (Vernoniinae)1 Rosario Redonda-Martı́nez, José Luis Villaseñor2, and Teresa Terrazas Instituto de Biologı́a, Universidad Nacional Autónoma de México, Departamento de Botánica, Apartado postal 70-367, 04510 México, D.F. REDONDA-MARTÍNEZ, R., J. L. VILLASEÑOR, AND T. TERRAZAS (Instituto de Biologı́a, Universidad Nacional Autónoma de México, Departamento de Botánica, Apartado postal 70-367, 04510 México, D.F.). Trichome diversity in the Vernonieae (Asteraceae) of Mexico I: Vernonanthura and Vernonia (Vernoniinae). J. Torrey Bot. Soc. 139: 235–247. 2012.—Trichomes on the leaves and florets of 17 Mexican species of Vernonanthura and Vernonia (Tribe Vernonieae, subtribe Vernoniinae) were studied using light and scanning electron microscopy (SEM), to assess their taxonomic value in distinguishing between these two genera. Earlier studies of North American Vernonieae by Jones and colleagues (Faust and Jones 1973, King and Jones 1975) showed that trichome morphology and their presence on leaves and reproductive structures could be taxonomically informative, but this work included few Mexican taxa. Glandular and nonglandular trichomes, each with several variants, were found in the two genera. Glandular trichomes were particularly abundant on the florets and the achenes while the nonglandular were more common on the leaves. A cluster analysis shows two main species groups based on trichome traits. The first group linked species lacking glandular trichomes in vegetative or reproductive organs, whereas in the second the species were grouped by the occurrence of uniseriate and glandular trichomes. Within this second group, two species possess unique features: Vernonanthura cordata has long uniseriate subtype b2 trichomes while in Vernonia greggii there are T-shaped trichomes on the leaf abaxial surface. Our results also showed that trichomes were useful in differentiating species with similar ecological and/or geographical features (e. g., Vernonia larsenii and V. lindheimeri), but were of limited taxonomic value at the generic level in distinguishing Vernonanthura from Vernonia. These two genera share various trichome types, but L-shaped trichomes were only found in Vernonanthura. An ongoing study of the Mexican Vernonieae may reveal informative trichome characters at different taxonomic levels, such as among subtribes, or between species of other more distantly related genera. Key words: Asteraceae, eglandular trichomes, glandular trichomes, Vernonanthura, Vernonia. The Asteraceae is one of the most diverse and widespread families of flowering plants. It is also the most diverse family in the flora of Mexico (Rzedowski 1993, Rzedowski and Calderón de Rzedowski 1995, Villaseñor 2003, Villaseñor 2004). The most characteristic feature of the family is its compacted inflorescence, termed a head, that includes many individual flowers (florets) tightly packed together and which is in turn surrounded by 1 We thank Alicia Rojas for her guidance during the light microscope work and for sample preparation. The Botanical Garden of the Instituto de Biologı́a, UNAM allowed us the use of the Anatomy Laboratory and facilitated the support of Estela Sandoval (technician) in many aspects of the work. The advice and help of Berenit Mendoza in charge of the SEM at the Instituto de Biologı́a is also gratefully acknowledged. Finally, we thank the curator of the Herbarium at the University of Texas at Austin (TEX) for the loan of specimens that were of great value to this study. Sterling C. Keeley and Claudio Delgadillo revised the manuscript and their comments helped to enrich its content. 2 Author for correspondence. E-mail: vrios@ ibiologia.unam.mx Received for publication September 9, 2011, and in revised form May 30, 2012. an involucre of bracts resembling a calyx. The florets are gamopetalous, epigynous and have syngenesious stamens. Additionally, the calyx is absent or modified into a specialized structure known as a pappus. Traditionally the family was subdivided into three subfamilies and 17 tribes (Bremer 1994). However, recent molecular and morphological studies have raised the number of tribes to 43 (Funk et al. 2009), 25 of which are known from Mexico (Villaseñor, unpublished data). These subtribes are distinguished from one another by such morphological features as style type and vestiture, corolla shape, lobe length, presence or absence of ray or ligulate florets, and the morphology of androecium, gynoecium, and fruit (a cypsela or achene). In addition, the trichomes have been found to be distinctive at the tribal level in numerous cases (Funk et al. 2009), as in the tribe Vernonieae, the subject of this study. In the American genera Critoniopsis Sch. Bip., Eremosis Gleason, and Tephrothamnus Sch. Bip., sometimes considered one single genus, there are distinctive trichome complements which clearly separate one from the 235 236 JOURNAL OF THE TORREY BOTANICAL SOCIETY other. Critoniopsis has stellate, spurred, or cup-shaped trichomes while Eremosis has simple trichomes; those of Tephrothamnus are T-shaped (Robinson 2009). Additionally, in Vernonia Schreb., trichomes have been used as diagnostic characters to distinguish species in temperate North American taxa (Faust and Jones 1973), to validate species status (Hunter 1967), and to identify hybrids (Hunter 1967, Hunter and Austin 1967). Trichomes have also been useful among Old World members of the tribe, to distinguish the Asian genus Acilepis D. Don, with simple trichomes, from Cyanthillium Blume, a closely related genus with T-shaped trichomes (Robinson 2009). The value of trichomes in distinguishing genera of closely related Mexican Vernonieae, however, is largely unknown. This study centers on the relevance of trichome morphology and location to evaluate the recent segregation of Vernonanthura H. Rob. from the core genus Vernonia (Robinson 1999, Keeley and Robinson 2009). Vernonia sensu stricto is a genus of 22 species (Robinson 1999), found in the temperate and tropical regions of both North and South America. The genus is characterized by few pedunculate heads, grouped in corymbs, and their species have Type A pollen (Robinson 1999). By comparison, Vernonanthura H. Rob. consists of 68 species distributed in tropical areas, from Mexico to Argentina; it is distinguished by its numerous sessile or short-peduncled heads and scorpioid cymes or pyramidal panicles, and shares the same Type A pollen with Vernonia (Robinson 1992, 1999). In México there are seven species of Vernonanthura and 11 species and two subspecies of Vernonia. Materials and Methods. The complete holdings of the Mexican species of Vernonanthura and Vernonia housed at the National Herbarium (MEXU) of the Instituto de Biologı́a, Universidad Nacional Autónoma de México, were reviewed along with selected specimens from the herbarium of the University of Texas at Austin (TEX) (Appendix 1). Leaf fragments, florets, and cypselae were removed from 17 species (Appendix 1). Two species (Vernonia barclayi H. Rob. & C.F. Reed and V. joyalieae B.L. Turner), known only from type material, could not be included in this study due to the impossibility of removing plant material. To prepare the leaf trichomes [VOL. 139 for observation under the light microscope the leaf fragments were hydrated for 2 h with distilled water and free-hand transverse sections were made with a razor blade. Temporary slides were prepared with glycerin jelly as mounting medium (López et al. 1998). The florets were hydrated using Aerosol/OT, dissected and mounted with Hoyer’s solution in temporary slides (Anderson 1954). The cypselae were hydrated for 2 h with tap-water, then placed for 10 min in a 10% NaOH solution and bleached (10% -v/v- aqueous solution of commercial Clorox) for 5 min, washed again with tap-water and prepared for observation as temporary Hoyer’s slides. Trichomes were described and photographed using a microscope Zeizz, Axioscop. For the scanning electron microscope (SEM) study, a second dried leaf fragment of each species was hydrated with tap-water and then taken through a 30% to 100% ethanol series, changing every 2 h, except for the 70% ETOH step where samples were held 24 h on a shaker table SEV, Agitador Orbital 6090 to remove waxes. Once dehydrated via the ETOH series, samples were fixed to aluminium specimen holders with double-sided tape and coated with gold in a Hitachi-S-2460N sputter coater prior to observation under a JEOL-JSM5310LV, 10 kW voltage, at the Instituto de Biologı́a, UNAM. Trichome description follows Faust and Jones (1973), except in those cases where additional terms were needed to accurately describe the observed subtypes. We generated a phenogram using a rectangular matrix with 17 terminals (species) and 15 characters. The characters were coded as binary and a distances matrix was obtained through use of the Manhattan coefficient; finally, a phenogram was obtained using the UPGMA method with NTSYS 2.02i (Rohlf, 1998). Results. Two types of trichomes were found in Vernonanthura and Vernonia: eglandular and glandular. The nonglandular trichomes were more common on the leaves (Table 1) whereas the glandular trichomes were most frequent on florets and cypselae (Table 2). The kind of trichomes and their typological occurrence are discussed below. Trichomes. LAGENIFORM TRIare unicellular, ovoid-elongated, widened on one side and acute on the other Eglandular CHOMES. These 2012] 237 REDONDA-MARTÍNEZ ET AL.: TRICHOMES IN MEXICAN VERNONIEAE Table 1. Diversity of eglandular trichomes in the Mexican species of Vernonanthura and Vernonia. (Ab 5 abaxial leaf surface; Ad 5 adaxial leaf surface.) Species Vernonanthura cordata Vernonanthura cronquistii Vernonanthura hintoniorum Vernonanthura liatroides Vernonanthura oaxacana Vernonanthura patens Veronanthura serratuloides Vernonia alamanii Vernonia bealliae Vernonia bolleana Vernonia faustiana Vernonia greggii Vernonia karvinskiana subsp. inuloides Vernonia karvinskiana subsp. karvinskiana Vernonia larsenii Vernonia lindheimeri Vernonia marginata Filiform Lageniform L-shaped T-shaped - Ab Ab - Ad Ab - Ad, Ab Ab Ab Ab Ab Ab Ab Ab Ab Ad, Ab Ab Ab Ab - Ad Ab, Ad Ad Ad Ad Ad Ad Ad Ad Ad Ad Ad Ab-b1, Ab-b2, Ab-b3 Ab-b1 Ab-b1 Ab-b1 Ab-b3 Ad-b1 Ab-b3 Ab-b1 - - Ab - - Ad Ab-b3 Ab Ab - Ab Ab - - Ad - Ab-b1 side (Fig. 1F). These trichomes correspond to the ‘‘awl-type’’ of Faust and Jones (1973). However, the term ‘‘lageniform’’ (potbellied at the base and distally narrowed, as the flaskshaped archegonia of musci) seems technically more appropriate (Font Quer 1985). Lageniform trichomes were mostly observed on the abaxial leaf surface, except in Vernonia bolleana, V. larsenii and V. lindheimeri which showed only filiform trichomes. Vernonanthura cronquistii and Vernonia greggii exhibited them on both leaf surfaces (Figs. 1A–F, 2G–I). FILIFORM TRICHOMES. These are long, slender one-celled structures, found abundantly on Table 2. Short-uniseriate Long-uniseriate - the abaxial leaf surface in Vernonia bolleana, V. larsenii, and V. lindheimeri (Fig. 1G), not seen in other species. Their presence separates these three species as a distinct subgroup in Vernonia (Fig. 3, Ia). SHORT-UNISERIATE TRICHOMES. They are curved and rigid, formed by 6–8 cells of equal length in one single series and are restricted to the adaxial leaf surface (Fig. 2A). These shortuniseriate trichomes were observed in most species, except in Vernonanthura cronquistii, Vernonia larsenii, V. lindheimeri, and V. marginata. Their lack in the species mentioned above helps to distinguish them as separate entities in their Distribution of glandular trichomes in the Mexican species of Vernonanthura and Vernonia. Species Vernonanthura cordata Vernonanthura cronquistii Vernonanthura hintoniorum Vernonanthura liatroides Vernonanthura oaxacana Vernonanthura patens Veronanthura serratuloides Vernonia alamanii Vernonia bealliae Vernonia bolleana Vernonia faustiana Vernonia greggii Vernonia karvinskiana subsp. inuloides Vernonia karvinskiana subsp. karvinskiana Vernonia larsenii Vernonia lindheimeri Vernonia marginata Adaxial leaf surface Abaxial leaf surface Corolla Androecium Cypsel + 2 + + 2 + + 2 2 + 2 + 2 + 2 + + 2 + + + + 2 2 + + + 2 + + + 2 + + + + 2 + + + 2 + + + 2 + + + 2 2 + + + 2 + + + 2 + + + 2 + + + + 2 2 + + + 2 + + + + + + 2 + + + 2 + + 238 JOURNAL OF THE TORREY BOTANICAL SOCIETY [VOL. 139 FIG. 1. Scanning electron microscopy (SEM) photographs of leaf trichomes. A–F. Lageniform trichomes (L), A. Vernonanthura cronquistii, B. Vernonia karvinskiana subsp. inuloides, C. Vernonia karvinskiana subsp. karvinskiana, D. Vernonanthura cordata, E. Vernonanthura serratuloides, F. Vernonia faustiana. G. Filiform trichomes (F) G. Vernonia larsenii. H–I Glandular trichomes (G), H. Vernonanthura serratuloides, I. Vernonia marginata. Scale bar 5 50 mm in B, D, F–H, 100 mm in E and I, 200 mm in A, 400 mm in C. respective groups in the phenogram (Fig. 3, II). LONG-UNISERIATE TRICHOMES. These are uniseriate 4–18 celled trichomes. Based on cell size variation three subtypes may be distinguished: Subtype b1 which has three short basal cells and one apical cell 8–10 times longer than the basal ones (Fig. 2B–D). Subtype b2 that has 10–12 basal cells of equal length plus one apical cell 1.5–2 times longer than the basal ones (Fig. 2E), and Subtype b3, with 10–18 cells of equal length. This last subtype is common on the abaxial leaf surface of Vernonanthura cordata, V. patens, Vernonia alamanii, and V. karvinskiana subsp. inuloides (Fig. 2F). The latter two taxa, Vernonia alamanii and V. karvinskiana subsp. inuloides, are similar in their trichomes complement (Fig. 3). Subtype b1 is seen on the abaxial leaf surface of Vernonanthura cordata, V. cronquistii, V. oaxacana, Vernonia beallieae, and V. karvinskiana subsp. karvinskiana as well as on the adaxial leaf surface of Vernonanthura serratuloides; subtype b2 trichomes are found exclusively on the abaxial leaf surface of Vernonanthura cordata. The occurrence of long uniseriate subtype b2 trichomes on the leaves on V. cordata help to separate it from the other species of group II (Fig. 3). T-SHAPED TRICHOMES. These are multicelular with 5–6 short basal cells of equal length plus one apical transversal cell, attached to the basal ones by the middle. They occurred on both leaf surfaces of Vernonia greggii and on the adaxial leaf surface of Vernonanthura serratuloides (Fig. 2G). The T-shaped trichomes on the abaxial surface of the leaves, is a character that separates Vernonia greggii from the other species of group II (Fig. 3). L-SHAPED TRICHOMES. These are multicelular trichomes with 8–10 short basal cells of equal length and one apical cell joined to the basal ones by one of its ends. They were observed on the abaxial leaf surface of Vernonanthura cordata, V. hintoniorum, V. 2012] REDONDA-MARTÍNEZ ET AL.: TRICHOMES IN MEXICAN VERNONIEAE 239 FIG. 2. Scanning electron microscopy (SEM) photographs of leaf trichomes. A. Short uniseriate trichomes (Su) A. Vernonia alamanii. B–F. Multicelular uniseriate trichomes (Subtype b1 (b1), subtype b2 (b2) subtype b3 (b3)), B. Vernonanthura cordata, C. Vernonanthura serratuloides, D. Vernonanthura oaxacana, E. Vernonanthura cordata, F. Vernonia karvinskiana subsp. inuloides, G. T-shaped trichomes (T), G. Vernonia greggii. H–I. L-shaped trichomes (Ls) H. Vernonanthura liatroides; I. Vernonanthura hintoniorum. Scale bar 5 300 mm in A, 100 mm in B–C, 200 mm in D–I. liatroides, and V. oaxacana (Table 1, Fig. 2H– I). The L-shaped trichomes occur exclusively in members of group II that belong to Vernonanthura (Fig. 3). Glandular Trichomes. Glandular trichomes are formed by 2–3 short basal cells plus a pair of semiglobose apical cells. They correspond to the bilobed trichomes of Faust and Jones (1973). They were frequently observed on both leaf surfaces as well as on the corolla tube and lobes, the androecium, and the cypselae of all species except Vernonanthura cronquistii (Table 2, Fig. 1H–I). The absence of glands in different organs defines the group Ib (Fig. 3), although glands may be occasionally present in one of them, as for example in Vernonia faustiana where glandular trichomes occur on the cypselae while in Vernonanthura patens they are found on both leaf surfaces. Cluster Analysis. In the cluster analysis (Fig. 3) the species separate into two main groups. The first (I) contains species without glandular trichomes or show them in either the florets or the leaves, but not on both structures. Group I may be subdivided in subgroup Ia that comprises species with filiform trichomes on the abaxial leaf surface; a second subgroup (Ib) brings together species usually with no glandular trichomes. The second group (II) includes species with glandular trichomes both on the florets and the leaves. Two species of this group are separated by their special kind of trichomes, Vernonanthura cordata with subtype b2 trichomes on the abaxial leaf surface, and Vernonia greggii, with T-type trichomes also on the abaxial surface. Both types of trichomes were not recorded in any other species studied and may be of taxonomic importance to differentiate them from closely related species. Discussion. Vernonanthura and Vernonia share a variety of glandular and eglandular trichome types. Most species studied have 240 JOURNAL OF THE TORREY BOTANICAL SOCIETY [VOL. 139 FIG. 3. Phenogram clustering 17 Mexican species of Vernonanthura (Vt) and Vernonia (Vn) based on trichomes diversity. The Manhattan distances coefficient and the UPGMA method were used to build up the phenogram. Species abbreviations are: alamanii (ala), bealliae (bel), bolleana (bol), cordata (cor), cronquistii (cro), faustiana (fau), greggii (gre), hintoniorum (hin), karvinskiana subsp. karvinskiana (kkar), karvinskiana subsp. inuloides (kinu), larsenii (lar) liatroides (lia), lindheimeri (lin), marginata (mar), oaxacana (oax), patens (pat), serratuloides (ser). glandular trichomes on all organs studied and nearly five types of eglandular trichomes on the leaf surface. These trichome types have diagnostic value at species level, but not at genus level. The presence or absence of glandular trichomes is the main character that defines two major species groups, but neither supports the recognition of either genera. The species of group 1 are distinctive by the absence of glandular trichomes in different organs. However, they may be present on the cypselae but not on the floral structures or on the leaves but not on the reproductive structures. The presence of glandular trichomes in certain plant structures suggests that there is not necessarily a correlation between their occurrence either on leaves or reproductive structures, rendering its taxonomic usefulness when comparing closely related species. Results show that some species pairs can be distinguished by type and location of the trichomes. For example, Vernonia larsenii and V. lindheimeri can be distinguished by the occurrence of glandular trichomes on the abaxial leaf surface in the former, and their absence, in the latter. Moreover, V. larsenii lacks glandular trichomes on the cypselae while V. lindheimeri possesses them. Similary, Vernonia faustiana and V. greggii, two mor- phologically similar species can be distinguished by the absence in the former of glandular trichomes on the leaves, corolla and androecium, and the T-shaped trichomes on the abaxial surface of the leaves. All these trichomes are absent in V. faustiana. Vernonanthura cordata and V. patens can also be easily confused; however, V. cordata possesses glandular trichomes on both leaf surfaces, the corolla, the androecium, and the cypsela, as well as long uniseriate subtype b2 trichomes. V. patens has glandular trichomes and long uniseriate subtype b3 trichomes on the leaves. In addition, V. cordata and V. patens differ in their synflorescence type (McVaugh 1984). The absence of glandular trichomes in Vernonanthura cronquistii allows us to distinguish it from the other Mexican species of Vernonanthura and Vernonia (Table 2). Trichomes can also be useful at subspecies level; for example, the occurrence of long-uniseriate trichomes (Type 4, subtype b1 with four cells) in Vernonia karvinskiana subsp. karvinskiana on the abaxial leaf surface distinguish it from V. karvinskiana subsp. inuloides, which has trichomes subtype b3 (with more than 10 cells) in the same position. There is considerable trichome diversity in the Vernonieae and specifically in the genus Vernonia sensu lato, as may be seen by four 2012] REDONDA-MARTÍNEZ ET AL.: TRICHOMES IN MEXICAN VERNONIEAE types of unicellular and 17 types of multicellular trichomes reported elsewhere (Cabrera 1944, Hunter and Austin 1967, Faust and Jones 1973, King and Jones 1975, Narayana 1979, Oladele 1990, Filizola et al. 2003, Adedeji and Jewoola 2008, Bonissoni and Duarte 2008), and an additional type reported here for the first time. This is a unicellular filiform trichome found on the abaxial leaf surface of Vernonia larsenii and V. lindheimerii. This type of trichome has only been recorded in members of the subtribe Espeletiinae (Robinson 2009), a phylogenetically distant group not related with Vernonieae. The lageniform (awl-shaped) unicellular trichomes, noted in some African Vernonieae, were common among the Mexican species here studied. Narayana (1979) described this type with two stipitate basal cells in Acilepis dalzelliana (J.R. Drumm & Hutch.) H. Rob. (cited as Vernonia dalzelliana J.R. Drumm. & Hutch.), and with three basal cells in Vernonia ramaswamii Hutch., and Vernonia travancorica Hook. f. These trichomes differ from the sessile lageniform trichomes observed in the Mexican species. In addition, Oladele (1990) reported the occurrence of lageniform trichomes with four or five stipitate basal cells in Gymnanthemum amygdalinum (Delile) Sch. Bip. ex Walp. (as Vernonia amygdalina Delile), calling them irregular T-shaped trichomes. Short-uniseriate trichomes were also common on the adaxial leaf surface of the Mexican species of Vernonanthura and Vernonia. Cabrera (1944) observed them on the abaxial leaf surface of the South American species Vernonanthura pinguis (Griseb.) H. Rob. (as Vernonia pinguis Griseb.) and Vernonanthura tweedieana (Baker) H. Rob. (as Vernonia tweedieana Baker). However, we did not find them on the adaxial leaf surface of any taxa, only on the abaxial surface. It is important to survey a larger number of species in the Vernonia complex, in order to evaluate Cabrera’s observation and see if the differences are consistent and taxomomically useful. The most common long-uniseriate trichomes type in the Mexican species studied was the subtype b1. This type has previously been described in Calea uniflora Less. (Tribu Heliantheae, Budel et al. 2006). Subtype b2, on the other hand, was rare in the Mexican species, only found in Vernonanthura cordata. However, subtype b2 was described in Old World Vernonieae, as in Cyanthillium ciner- 241 eum (DC.) H. Rob. (cited as Vernonia albicans DC.) and Acilepis peninsularis (C.B. Clarke) H. Rob. & Skvarla (cited as Vernonia peninsularis (C.B. Clarke) C.B. Clarke ex Hook. f.) by Narayana (1979) and in Gymnanthemum amygdalinum (cited as Vernonia condensata Baker) by Lolis and Milaneze-Gutierre (2003) and Narayana (1979). Subtype b3, here observed in two species of Vernonanthura and one of Vernonia, were also recorded in Baccharis anomala DC. (Tribe Astereae, Budel and Duarte 2008), and Bidens pilosa L. (Tribe Coreopsideae, Ferreira et al., 2002) but not previously found in any other member of the Vernonieae. T-shaped and L-trichomes were also rare in the Mexican species here studied but have been recorded in other species of Vernonia (Hunter and Austin 1967, Narayana 1979, Oladele 1990, Filizola et al. 2003). Narayana (1979) also mentions the occurrence of the Tshaped trichomes in other members of the tribe, but those differed from the ones here described in the number of basal cells (8) or the length of the apical cell (4–5 times longer than the basal cells). Other species of Asteraceae such as Urostemon kirkii (Hook. f. ex Kirk) B. Nord. var. kirkii (Tribe Senecioneae, Nordenstam, 1978) have similar T-shaped trichomes with 3–4 basal cells. Glandular trichomes on leaves are common in other members of the Vernonieae, as well as in Vernonanthura and Vernonia (Cabrera 1944, Narayana 1979, Oladele 1990, Filizola et al. 2003, Milan et al. 2006) and on the cypsela of Vernonia vivekanathanii Uniyal (as Vernonia monosis Benth. ex C.B. Clarke in Narayana 1979). Glandular trichomes with no basal cells (sessile glandular trichomes sensu Adedeji and Jewoola 2008) have been recorded on the leaves of Gymnanthemum amygdalinum (as Vernonia amydgalina) and Cyanthillium cinereum (as Vernonia cinerea (L.) Less., Adedeji and Jewoola 2008). The latter species is an adventive species in Mexico and is under current study to document its trichome diversity. Sessile glandular trichomes are also known in other members of the Asteraceae, for example, on the leaf surfaces of Ageratum fastigiatum (Gardner) R.M. King & H. Rob. (Tribe Eupatorieae, Del-Vechio-Vieira et al., 2008), Artemisia annua L. (Tribe Anthemideae, Duke and Paul, 1993), Baccharis cordifolia DC. (Tribe Astereae, Budel and Duarte 2007), Baccharis dracunculifolia DC. (Tribe 242 JOURNAL OF THE TORREY BOTANICAL SOCIETY Astereae, Budel et al. 2004), Elephantopus mollis Kunth (Tribe Vernonieae, Bonissoni and Duarte 2008) or Stevia rebaudiana (Bertoni) Bertoni (Tribe Eupatorieae, Cornara et al. 2001, Rossi et al. 2001). The florets in some taxa, such as Artemisia annua (Ferreira and Janick 1995) and Stevia rebaudiana (Cornara et al. 2001) and the cypsela of Mikania micrantha Kunth (Tribe Eupatorieae, Rejane and Sffogia 2006), Pacourina edulis Aubl. (Tribe Vernonieae, Cabrera 1944) and Stevia rebaudiana (Cornara et al. 2001) also have similar trichomes. It seems likely these glandular trichomes are more common on florets and cypsela that is currently understood because trichomes are generally studied on the leaves, but not on other organs. As discussed previously, there appears to be no trichomes occurrence correlation among organs, so it is of interest to evaluate them in all plant structures to support this assertion. Conclusions. We conclude that trichomes have potential taxonomic value in differentiating morphologically similar species and clusters of species sharing ecological and/or geographical features (e.g., Vernonia larsenii and V. lindheimeri). Additionally, only two species of Vernonia share the same full trichome complement (Vernonia alamanii and V. karwinskiana subsp. inuloides). These taxa, although morphologically similar, have a suite of other characters that clearly distinguish them as separate species (Jones 1976), in addition to their distinct geographic distribution. Overall, our results support those of Faust and Jones (1973) that show that the taxonomic value of trichomes increases when they are combined with other morphological data and information about the geographical distribution of species. The study of trichomes diversity in the remaining members of the tribe Vernonieae in Mexico may prove useful in the taxonomy and systematics of the tribe. The presence or absence and kind of trichomes were not enough to differentiate the two genera studied. However, at the species level such characters can be useful to distinguish morphologically similar species. For example, as indicated above, Vernonia fasutiana can be distinguished from V. greggii based on trichome complement, and although morphologically similar, the two species are nested in different groups in the cluster analysis (Fig. 3). Likewise, Vernonanthura cordata and [VOL. 139 V. patens, two closely related and morphologically similar species, differ in the occurrence of glandular trichomes on the florets of the former. The study of a broader universe of Mexican species and genera undoubtedly will support the preliminary results of this study and will reinforce the conclusions here discussed about the taxonomic importance of the trichomes in the systematics of the tribe. Literature Cited ADEDEJI, O. AND O. A. JEWOOLA. 2008. Importance of leaf epidermal characters in the Asteraceae Family. Notul. Bot. Horti Agrobot. Cluj-Napoca Inst., Agron. Dr. Petru Groza. 36: 7–16. ANDERSON, L. E. 1954. Hoyer’s solution as a rapid permanent mounting medium for Bryophytes. Bryologist 57: 242–244. BONISSONI, E. C. AND M. R. DUARTE. 2008. Estudio anatômico de folha e caule de Elephantopus mollis Kunth (Asteraceae). Rev. Bras. Farmacogn. 18: 108–116. BREMER, K. 1994. Asteraceae. Cladistics and Classification. Timber Press, Portland OR. 752 p. BUDEL, J. M. AND M. R. DUARTE. 2007. Caracteres morfoanatômicos de partes vegetativas aéreas de Baccharis cordifolia DC. (Asteraceae-Astereae). Lat. Am. J. Pharm. 26: 723–731. BUDEL, J. M. AND M. R. DUARTE. 2008. Estudio farmacobotânico de partes vegetativas aéreas de Baccharis anomala DC., Asteraceae. Rev. Bras. Farmacogn. 18(Supl.): 761–768. BUDEL, J. M., M. R. DUARTE, P. V. FARAGO, AND I. J. M. TAKEDA. 2006. Caracteres anatomicos de folhae caule de Calea uniflora Less., Asteraceae. Rev. Bras. Farmacogn. 16: 53–60. BUDEL, J. M., M. R. DUARTE, C. A. M. SANTOS, AND P. V. FARAGO. 2004. Morfoanatomia foliar e caulinar de Baccharis dracunclifolia DC., Asteraceae. Acta Farm. Bonaerense 23: 477–483. CABRERA, A. L. 1944. Vernonieas Argentinas. Darwiniana 6: 19–379. CORNARA, L., M. BONONI, E. TATEO, G. SERRATOVALENTI, AND M. G. MARIOTTI. 2001. Trichomes on vegetative and reproductive organs of Stevia rebaudiana (Asteraceae). Structure and secretory products. Pl. Biosystems 135: 25–37. DEL-VECHIO-VIEIRA, G., M. V. D. BARBOSA, B. C. LOPES, O. V. SOUZA, L. D. R. SANTIAGOFERNANDES, R. L. ESTEVES, AND M. A. C. KAPLAN. 2008. Caracterição morfoanatômica de Ageratum fastigiatum Asteraceae. Rev. Bras. Farmacogn. 18(Supl.): 769–776. DUKE, S. O. AND R. N. PAUL. 1993. Development and fine structure of glandular trichomes of Artemisia annua L. Int. J. Plant Sci. 154: 107–118. FAUST, W. Z. AND S. B. JONES JR. 1973. The systematic value of trichome complements in a North American group of Vernonia (Compositae). Rhodora 75: 517–528. FERREIRA, J. S. F. AND J. JANICK. 1995. Floral morphology of Artemisia annua with special 2012] REDONDA-MARTÍNEZ ET AL.: TRICHOMES IN MEXICAN VERNONIEAE reference to trichomes. Int. J. Plant Sci. 156: 807–815. FERREIRA, E. A., S. O. PROCÓPIO, E. A. M. SILVA, A. A. SILVA, AND R. J. N. RUFINO. 2002. Estudos Anatômicos de folhas de espécies de plantas daninhas. II – Bidens pilosa, Emilia sonchifolia, Ageratum conyzoides e Sonchus asper. Planta Daninha. 20: 327–335. FILIZOLA, L. R., R. M. PIMENTEL, K. P. RANDAU, AND H. S. XAVIER. 2003. Anatomia dos Órgãos Vegetativos de Vernonia brasiliana (L.) Druce. Acta Farm. Bonaerense 22: 299–303. FONT-QUER, P. 1985. Diccionario de Botánica. Labor. España 1244 p. FUNK, V. A., A. SUSSANA, T. F. STUESSY, AND H. ROBINSON. 2009. Classification of Compositae. p. 171–189. In V. A. Funk, A. Sussana, T. F. Stuessy, and R. J. Bayer [eds.], Systematics, Evolution and Biogeography of the Compositae. IAPT, Vienna, Austria. HUNTER, G. E. 1967. Chromatographic documentation of interespecific hybridization in Vernonia: Compositae. Am. J. Bot. 54: 473–477. HUNTER, G. E. AND D. E. AUSTIN. 1967. Evidence from trichome morphology of interspecific hybridization in Vernonia: Compositae. Brittonia 19: 38–41. JONES, S. B. 1976. Revision of Vernonia (Compositae), Subsection Paniculatae, Series Umbelliformes of the Mexican highlands. Rhodora 78: 180–206. KEELEY, S. C. AND H. ROBINSON. 2009. Vernonieae, p. 439–469. In V. A. Funk, A. Sussana, T. F. Stuessy, and R. J. Bayer [eds.], Systematics, Evolution and Biogeography of the Compositae. IAPT, Vienna, Austria. KING, B. L. AND S. B. JONES. 1975. The Vernonia lindheimeri complex (Compositae). Brittonia 24: 74–86. LOLIS, M. I. G. A. AND M. A. MILANEZE-GUTIERRE. 2003. Morfo-anatomia das folhas de Vernonia condensata Baker (Asteraceae) o ‘‘figatil’’. Rev. Brasil. Farmacogn. 13(Supl.): 68–71. LÓPEZ, C., M. L., J. MÁRQUEZ G., AND G. MURGUÍA S. 1998. Técnicas para el estudio del desarrollo de angiospermas. Facultad de Ciencias, UNAM, D.F. México. 116 p. MCVAUGH, R. 1984. Compositae. Flora NovoGaliciana 12: 1–1157. MILAN, P., A. H. HAYASI, AND B. APPEZZATO-DAGLÓRIA. 2006. Comparative leaf morphology of three Asteraceae species. Braz. Arch. Biol. Technol. 49: 135–144. NARAYANA, B. M. 1979. Taxonomic value of trichomes in Vernonia Schreb. (Asteraceae). Proc. Indian Acad. Sci. B. 88: 347–357. NORDERSTAM, B. 1978. Taxonomic studies in the tribe Senecioneae (Compositae). Opera Bot. 44: 1–83. OLADELE, F. A. 1990. Leaf epidermal features in Vernonia amygdalina and Vernonia cinerea. Niger. J. Bot. 3: 71–77. REJANE, R. M. AND S. T. SFFOGIA M. 2006. Micromorfologia da superfı́cie do fruto de espécies de Mikania Willd. (Asteraceae) ocorrentes no Estado do Rio Grande du Sol, Brasil. Acta Bot. Bras. 20: 241–247. 243 ROBINSON, H. 1992. A new genus Vernonanthura (Vernonieae, Asteraceae). Phytologia 73: 65–76. ROBINSON, H. 1999. Generic and subtribal classification of American Vernonieae. Smith. Contr. Bot. 89: 1–116. ROBINSON, H. 2009. An introduction to microcharacters of Compositae, p. 89–100. In V. A. Funk, A. Sussana, T. F. Stuessy, and R. J. Bayer [eds.], Systematics, Evolution and Biogeography of the Compositae. IAPT, Vienna, Austria. ROHLF, F. J. 1998. NTSYS-PC. Numerical Taxonomy and Multivariate Analysis System. Ver. 2.02i. Exeter Software, New York, NY. ROSSI, M. W., M. DE MORALES C., S. C. MAZZONIVIVEROS, AND P. G. MAHLBERG. 2001. Development and some hystochemical aspects of foliar glandular trichomes of Stevia rebaudiana (Bert.) Bert.-Asteraceae. Rev. Bras. Bot. São Paulo 24: 349–357. RZEDOWSKI, J. 1993. Diversity and origins of the phanerogamic flora of Mexico, p. 149–144. In T. P. Ramamoorthy, R. Bye, A. Lot, and J. Fa [eds.], Biological diversity of Mexico: Origins and distribution. Oxford University Press, London, UK. RZEDOWSKI, J. AND G. CALDERÓN DE RZEDOWSKI. 1995. Flora del Bajı́o y Regiones Adyacentes. Vol. 38, Familia Compositae, Tribu Vernonieae. Instituto de Ecologı́a, Pátzcuaro, México. VILLASEÑOR, J. L. 2003. Diversidad y distribución de las Magnoliophyta de México. Interciencia 28: 160–167. VILLASEÑOR, J. L. 2004. Los géneros de plantas vasculares de la flora de México. Bol. Soc. Bot. Méx., México. 75: 105–135. Appendix 1. Specimens used in the trichomes survey of Mexican species of Vernonanthura and Vernonia (C 5 specimens used to obtain cypsela; F 5 specimens used to obtain florets; L 5 specimens used to obtain leaves). 1) Vernonia alamanii DC., Prodr. 5: 61. 1836. Guanajuato. Mpio. Xichú, Santa Rosa, 12 km SO de Xichú 21u169480N 100u049430O. 9 feb 1989, Ventura et al. 6577 (MEXU) [C, L]. Guerrero. Mpio. General Heliodoro Castillo, El Jilguero, 5.7 km NO. 17u329100N 100u239230O. 2530 m, 16 ene 1999, CruzDurán 3624 (MEXU) [F, L]. Hidalgo. Mpio. Jacala. Cuesta Colorada, 12 km NE de Jacala, 21u019360N 99u069540O. 1900 m, 12 feb1982, Hernández-Magaña et al. 6958 (MEXU) [F, L]. Jalisco. Mpio. Mazamitla. 12 km NE de El Zapatero, sobre la desviación a Dos Rı́os 19u569530N 102u569430O. 2045 m, 9 abr 1988, Garcı́a-Mendoza. et al. 3925 (MEXU) [F, L]. México, 6 mi al N de Valle de Bravo sobre la nueva carretera, 4 dic 1972, Jones et al. 22398 (MEXU) [F, L]. Michoacán. Mpio. Jiquilpan, 1 km O de Jiquilpan, 21 km E del lı́mite Jalisco-Michoacán. Matorral, 2160 m, 17 feb 1987, Spellenberg et al. 8989 (MEXU) [C, F, L]. Mpio. Pátzcuaro, ladera occidental del Cerro los Lobos 19u309100N 101u329210O. 2300 m, 7 ene 1986, Dı́az-Barriga 1938 (MEXU) [F, L]. Morelos. Mpio. Tepoztlán, autopista México-Cuernavaca km 55. 19u009000N 99u079000O. 2350 m, nov 1959, Espinosa 257 244 JOURNAL OF THE TORREY BOTANICAL SOCIETY (MEXU) [F, L]. Puebla. Mpio. Honey, Arroyo Grande, 7 km SE de Chila 20u169000N 98u149000O. 1750 m, 23 feb 1987, Tenorio et al. 12502 (MEXU) [C, L]. Querétaro. Mpio. Pinal de Amoles, 4 km NE de San Pedro el Viejo, sobre el camino a la Yerbabuena 21u059440N 99u319340O. 1700 m, 4 abr 1987, Rzedowski 43019 (MEXU) [F, L]. San Luis Potosı́, 11 mi OSO de Xilitla sobre la carretera 120, 30 nov 1972, Jones et al. 22375 (MEXU) [F, L]. Veracruz. Mpio. Huayacocotla, El Tine. 2000 m, 21 dic 1970, Hernández-Magaña et al. 986 (MEXU) [F, L]. 2) Vernonia bealliae McVaugh, Contr. Univ. Mich. Herb. 9(4): 479. 1972. Jalisco, 0.5–0.75 km NO de Rincón de Manantlán 19u369000N 104u129450O. En la base de la Sierra de Manantlán, 13 km S de El Chante. 1520 m, 4 ene 1979, Iltis et al. 1175 (MEXU) [F, L]. 15.7 km por la carretera N de El Terreno, sobre la carretera a La Laguna; 35.5 km NO de Colima; 38 km OSO del Nevado de Colima 19u309570N 103u589290O. 2113 m, 23 mar 1989, Wetter et al. 2062 (MEXU) [F, L]. Mpio. Cuautitlán, La Cumbre camino a Guzalapa 16–17 km NE de Cuautitlán, de 5–6 km SE de E. C. L. J. 19u339100N 104u149200O. 2100 m, 17 may 1990, Cuevas et al. 3853 (MEXU) [C, F, L]. Mpio. Chiquilistán, 6–5 km S de Chiquilistán ca. 5 km por la carretera, al SO de la Unión a Saucillo, mina de mercurio. 20u029560N 103u509400O. 1800 m, 31 ene 1975, McVaugh 25995 (MEXU) [C, F, L]. Desviación al Rancho El Rodeo; camino a la presa, 3.13 km SE de Tapalpa. 4 mar 1981, Conrado S/n (MEXU) [F, L]. Estación de Biologı́a Las Joyas en la Sierra de Manantlán, entrando por el Chante carretera Autlán-El Grullo 19u349N 104u179O. 9 mar 1992, Campos 4561 (MEXU) [F, L]. Mpio. Ciudad Guzmán, proximidades a El Jazmı́n. 1700 m, mar 1982, Guı́zar 878 (MEXU) [F, L]. Mpio. Jocotepec, Cerro Viejo ‘‘Barranca del agua’’; subiendo por Zapotitlán de Hidalgo. 2050 m, 5 mar 1989, Cházaro et al. 5883 (MEXU) [F, L]. Mpio. San Sebastián del Oeste. El Segundo Arroyo, brecha San Sebastián-El Real Alto. 1600 m, 6 abr 1993, Reynoso et al. 1237 (MEXU) [C, F, L]. Mpio. Tecalitlán, Sierra del Halo. 1390 m, 6 jun 1995, Reynoso et al. 2482 (MEXU) [F, L]. Mpio. Tlapalpa, 13 km SO de Tlapalpa, brecha a El Salto del Nogal 19u539480N 103u479090O. 5 mar 1981, Lott et al. 316 (MEXU) [F, L]. Michoacán. Mpio. Aguililla, 24 km NO de Aguililla. 2140 m, 9 abr 1985, Soto et al. 8133 (MEXU) [F, L]. Mpio. Coalcomán, en las Agüitas, aprox. 20 km NE de Coalcomán, camino a Dos Aguas. 1775 m, 28 mar 1980, Soto et al. 2158 (MEXU) [C, F, L]. 3) Vernonia bolleana Sch. Bip. Bot. Voy. Herald. 297. 1856 Sinaloa. Mpio. Concordia, camino Potrerillos-La Petaca-El Cuantanal, desecho La Laja, 10 km de La Petaca 23u239540N 105u459370 1700 m. 28 nov 2010. Vega et al. 11666 (MEXU) [C,F,L] 4) Vernonia faustiana (G.C. Chapman & S.B. Jones) B.L. Turner, Phytologia 65: 136. 1988. Coahuila. Mpio. Múzquiz, Cañón Rincón de Marı́a, en la Sierra de la Babia 28u279490N 102u049300O. 1450 m. 21 ago 1999. Carranza 3047 (TEX) [C, F, L]. Rincón de Marı́a 28u279300N [VOL. 139 102u049000O. 1750 m. 23 ago 1975. Wendt 1273, 1273a (TEX) [C, L]. Sierra Encantada at Rincón de Marı́a, about 5 mi S of Hacienda La Babia, with the base camp. 28u279300N 102u049000O. 1700 m. 23 ago 1998. Henrickson 20594-3 (TEX) [C, F, L]. 5) Vernonia greggii A. Gray, Proc. Amer. Acad. Arts 17: 204. 1882. Coahuila. Mpio. Arteaga, 1.3 mi E de Los Lirios 25u239N 100u349O. 22 jul 1981, Poole 2366 (MEXU) [F, L]. Mpio. Castaños. Sierra La Gavia, en Cañada La Gavia; 8 km O de la carretera Saltillo-Monclova 26u209N 101u159O. 1500 m, 12 may 1992, Mayfield et al. 1331 (MEXU) [F, L]. El Recreo, S de Saltillo. 2200 m, jul 1942, Lyonnet 3600 (MEXU) [C, F, L]. Durango. Mpio. Mapimi, de Bermejillo a Mapimi, 25u539160N 103u379170O. 1200 m, 8 jul 1976, Sánchez-Mejorada 2578 (MEXU) [C, F, L]. Hidalgo. Mpio. Zimapán, 10 km N de Zimapán, hacı́a la mina de San Miguel. 2200 m, 28 jun 1981, Hernández-Magaña et al. 6256 (MEXU) [F, L]. Nuevo Leó n. Mpio. Galeana, Cerro Potosı́ 24u539300N 100u109300O. 1800 m, 28 ago 1987, Bogler et al. 191 (MEXU) [C, L]. Mpio. Galeana. Pablillo 5 km E. 24u369N 99u599150O. 15 may 1984, Hinton et al. 18665 (MEXU) [F, L]. Querétaro. Mpio. de Jalpan, Cañada del Pinalito 21u229280N 99u159170O. 1100 m, 18 ago 1966, Zamudio et al. 9931 (MEXU) [F, L]. Tamaulipas. Mpio. Aldama. Las Yucas a lo largo de la carretera de S-N del pueblo Las Yucas 2.2 mi. 23u139000N 98u099300O. 12 jul 1991, Mayfield, et al. 858 (MEXU) [C, F, L]. Mpio. Jaumave, 12 km S de Ávila y Urbina. 1600 m, 23 sep 1984, González-Medrano 14179 (MEXU) [F, L]. San Luis Potosı́. Mpio. Guadalcázar, 1 km N de la entrada a San José de Cervantes 22u349120N 10u279100O. 23 abr 1997, R. Torres et al. 15021 (MEXU) [F, L]. 6a) Vernonia karvinskiana DC. subsp. inuloides (DC.) S.B. Jones, Rhodora 78: 194. 1976. Oaxaca. Dto. del Centro. Mpio. San Andrés Huayapan, 2 km S del Estudiante, carretera OaxacaIxtlán 18u089160N 96u379160O. 1800 m, 14 ene 1986, Garcı́a-Mendoza et al. 1957 (MEXU) [F, L]. Dto. Juquila. Mpio. San Juan Lachao, 20 km SE del Vidrio (entronque a Juquila), 28 km N de San Gabriel Mixtepec 16u089120N 97u109410O. 1930 m, 24 sep 1982, Téllez 6044 (MEXU) [F, L]. Dto. Miahuatlán. Mpio. San Jerónimo Coatlán. Espuelas de San Antonio, 13.5 km de San Jerónimo Coatlán, brecha a Piedra Larga 16u129N 96u579O. 1950 m, 21 dic 1988, Campos 2714 (MEXU) [C, F, L]. Dto. Mixe. Mpio. Santa Marı́a Tlahuitoltepec, 4 km E de Tlahuitoltepec, 3 km N de Tamazulapan 17u05 030N 96u069570O. 17 ene 1986, Garcı́a-Mendoza et al. 1983 (MEXU) [C, F, L]. Dto. Tlacolula. Mpio Villa Dı́az Ordaz, 8 km N de Dı́az Ordaz 17u019110N 96u249590O. 2200 m, 8 jul 1982, Cedillo et al. 1919 (MEXU) [F, L]. Mpio. Ixtlán de Juárez, 10 km N de Ixtlán de Juárez sobre la carretera a Valle Nacional 17u239300N 96u299450O. 2400 m, 20 mar 1984, Cronquist 11854 (MEXU) [C, F, L]. Mpio. San Andrés Paxtlan, 20 mi SE de Miahuatlán. 2280 m. 29 oct 1967, H. S. Gentry 22390 (MEXU) [C, F, L]. Mpio. San Pedro Pochutla, 14 km del Puente de Jalatengo, 7 km E de San Pedro El Alto. 16u019140N 96u 319140O. 2110 m, 24 nov 1977, Delgado et al. 710 2012] REDONDA-MARTÍNEZ ET AL.: TRICHOMES IN MEXICAN VERNONIEAE (MEXU) [F, L]. Mpio. Santa Catarina Juquila, 12 mi S de Sola de Vega, 90 mi N de Puerto Escondido 16u 269460N 97u039120O. 2100 m. 7 nov 1965, Cronquist et al. 10504 (MEXU) [F, L]. Mpio. Santiago Matatlán, 3 km S de Matatlán (Torre de Microondas) 16u509530N 96u219380O. 19 dic 1979, González-Medrano 11503 (MEXU) [F, L]. Mpio. Totontepec, kms 94-96 de la carretera MitlaTotontepec. Cerro Cempoaltepetl. 17u059N 96u039O. 2550 m, 11 ene 1989, Todzia 2852 (MEXU) [C, F, L]. Mpio. Villa Sola de Vega, 16 km O de Villa Sola de Vega 16u329190N 96u589520O. 2080 m, 22 nov 1977, Delgado 632 (MEXU) [C, F, L]. 6b) Vernonia karvinskiana DC. subsp. karvinskiana, Prodr. 5: 61. 1836. Oaxaca. Mpio. Comaltepec, Loma Colorada. 1600 m, 16 nov 1978, Ventura 15550 (MEXU) [C, F, L]. Mpio. Santiago Yosondúa, 12 km S de Chalcatongo, 64 km S de Tlaxiaco, por el camino a Yosondúa. 97u339310N 16u559360O. 19 dic 1989, Villaseñor et al. 1173 (MEXU) [C, F, L]. Dto. Centro. Mpio. Oaxaca, Cerro San Felipe del Agua. 1850 m, 17 nov de 1984. Saynes 87 (MEXU) [F, L]. Dto. Santiago Juxtlahuaca. Mpio. San Juan Mixtepec, 4 km S de Tres Cruces. Vegetación riparia, 2000 m, 10 nov 1988. Reyes-Santiago 1179 (MEXU) [C, F, L]. Mpio. Santos Reyes Tepejillo, 4 km N de Santos Reyes Tepejillo, entrada por la Cruz, rı́o Boquerón 17u279N 97u569O. 1525 m, 31 oct 1995. Calzada 20331 (MEXU) [F, L]. Mpio. San Sebastián Tecomaxtlahuaca, 10 km de San Sebastián Tecomaxtlahuaca, carretera a San Martı́n Duraznos. 17u189N 98u059O. 1755 m, 2 nov 1996, Calzada 20367 (MEXU) [F, L]. Dto. Teposcolula. Mpio. Villa de Tamazulapan del Progreso, 3 km de Tamazulapan por la carretera de terracerı́a rumbo a San Andrés Lagunas 19u32929.20N 97u31912.020O. 2250 m, 1 dic 2002, Calzada 23537 (MEXU) [F, L]. Mpio. San Sebastián Nicanduta, 11.7 km de Santiago Xolomécatl, carretera de terracerı́a rumbo a Nicanduta 17u309420N 97u38957.90O. 2350 m, 23 dic 2002, Calzada 23659 (MEXU) [F, L]. Dto. Tlaxiaco. Mpio. San Martı́n Itunyoso, 11 km SO de San Isidro Chicahuaxtla, carretera Tlaxiaco-Putla 17u109560N 97u539000O. 1 dic 1993, R. Torres 14214 (MEXU) [F, L]. Dto. Zaachila, 7 km O de ‘‘Santiago Clavellina’’, hacı́a San Antonio Huitepec. 18 sep 1982, R. Torres et al. 1303 (MEXU) [F, L]. 7) Vernonia larsenii B.L. King & S.B. Jones, Brittonia 27(1): 84. 1975. Coahuila. Mpio. Acuña. 25 mi E of Rancho Chupadero del Caballo by road in Cañon del Colorado, 29u279330N 101u289500O. 500 m. 10 oct 1968. Patterson 76 (TEX) [C, F, L]. Mpio. Múzquiz. Múzquiz. 27u549170N 101u289440O. 7 abr 1936. Ernest 257 (TEX). [C, F, L]. Mpio. Ocampo. Rocky limestone soil in long pass through Babia Mountains, on road to rancho Las Norias from San Miguel. 28u389100N 103u099500O. Powell 1440 (TEX). [C, F, L]. 8) Vernonia lindheimeri A. Gray & Engelm., Proc. Am. Acad. Arts 1: 46. 1846. Coahuila. Mpio. Múzquiz. Hacienda Mariposa, 28u079440N 101u449580O. 1936, Anonimo 8751 (MEXU) [C, F, L]. Texas. Condado Medina, 4.2 mi O de la unión de FM 1283 y FM 475, O de 245 San Antonio. 6 jul 1989, Lierens 4059 (MEXU) [C, F, L]. Condado Travis, ladera caliza, NO de Austin. 5 ago 1969, Jones 17662. (MEXU) [F, L]. Condado Williamson, 600 mi N del Condado Travis. Pradera. 27 jun 2000, Harms 4 (MEXU) [F, L]. 9) Vernonia marginata (Torr.) Raf., Atl. Jour. 146. 1832. Coahuila. Mpio. Guerrero, 6 km SO de Castillon. 28u159N 100u189O. Vegetación riparia, 16 jun 1941, Stewart 561 (MEXU) [F, L]. Texas. Presidio County, 1 mi O of Sauceda. 29u289200N 103u589500O. 1275 m, 10 oct 1997, Webster 32532 (MEXU) [C, F, L]. 10) Vernonanthura cordata (Kunth) H. Rob., Phytologia 73(2): 70. 1992 Colima. Mpio. Comala, Carretera Carrizalillo-El Jabalı́ 19u259470N 103u409500O. 1250 m, 30 mar 1998. Román 2291 (MEXU) [C, F, L]. Guerrero. Mpio. Pungarabato, en el Cuidancito, 94 km SO de Ciudad Altamirano, 17u559560N 101u139350O. 1060 m, 16 jun 1994, Martı́nez-Salas 3668 (MEXU) [F, L]. Mpio. Zirándaro, Guayameo, 8.5 km SO 18u1597.90N 101u19914.90O. 820 m, 23 mar 1999. Calónico 14456 (MEXU) [C, F, L]. Jalisco. Mpio. Jilotlán, El Arroyito, 6 km N de Huapala. 1390 m, 5 abr 1988, Garcı́a-Mendoza et al. 3709 (MEXU) [C, F, L]. Mpio. Tonila, cuesta al volcán de Colima, aprox. 6 km de la carretera Atenquique-Colima, 19u269320N 103u289260O. 1000 m, 16 jun 1994, Sandoval S/n (MEXU) [F, L]. México. Hacienda Dolores, San Miguel Amatepec. 700 m, Matuda 30539 (MEXU) [F, L]. Temascaltepec, 5 km NE; por la carretera a Toluca. 19u029N 100u029O. 1590 m, 24 mar 1996, Villaseñor 1325 (MEXU) [F, L]. Michoacán. Mpio. Ario de Rosales, 3 km SO de Ario de Rosales. 19u129110N 101u449250O. 1900 m, 15 mar 1985. Soto 7690 (MEXU) [C, F, L]. Mpio. Zitácuaro, en la Garita 3 km SO de Zitácuaro, 1800 m, 6 mar 1985, Soto 7237 (MEXU) [F, L]. Mpio. Zitácuaro, en Coatepec, 4 km SO de Zitácuaro. 1900 m, 7 mar 1985, Soto et al. 7305 (MEXU) [F, L]. Mpio. Zitácuaro, carretera Zitácuaro-Tuzantla, 8 km SO de Zitácuaro, en lugar llamado El Banco 19u239140N 100u239590O. 1770 m, 22 mar 1982. Soto 3834 (MEXU) [F, L]. Morelos. Cuernavaca. 12 mar 1980. Ortega 12 (MEXU) [C, F, L]. Mpio. Yautepec, carretera Yautepec-Tepoztlán. 1420 m, 3 mar 1987. Quezada 1564 (MEXU) [F, L]. Nayarit. Mpio. Compostela, 3 mi N de Compostela, sobre la carretera 200, 21u179240N 104u559130O. 1000 m, 17 may 1973. Hansen et al. 1420 (MEXU) [C, F, L]. 11) Vernonanthura cronquistii (S.B. Jones) H. Rob., Phytologia 73(2): 70. 1992. Guerrero. Cerca de la carretera Acapulco-Cuernavaca, 0.5 mi S de Agua de Obispo. 1950 m, 14 oct 1984, Spooner et al. 2623 (MEXU) [C, F, L]. Cerca de la estación de microondas El Fresno, 50 km S de Chilpancingo. 1000 m, 12 oct 1974, Cronquist 11227 (MEXU) [C, F, L]. Chilpancingo, sobre la carretera Acapulco; 34 km S de Chilpancingo. 850 m, 11 oct 1974, Cronquist 11226 (MEXU) [F, L]. Mpio. Chilpancingo, 5 km O de El Ocotito, camino a Jaleaca, 17u169040N 99u329530O. 700 m, 24 nov 1983, Martı́nez-Salas et al. 5751bis (MEXU) [C, F, L]. Mpio. Chilpancingo, Rincón Viejo 17u179400N 99u289540O. 725 m, 10 oct 1959, Kruse 739 (MEXU) 246 JOURNAL OF THE TORREY BOTANICAL SOCIETY [F, L]. Mpio. Malinaltepec, Malinaltepec, 17u149390N 98u409390O. 1700 m, 26 nov 1989, Wagenbreth 335 (MEXU) [F, L]. Oaxaca. Dto. Putla, Santa Marı́a Yucuhiti, 7 km NE de Putla. 17u029330N 97u529450O. 840 m, 9 dic 1982, Rico et al. 575. (MEXU) [C, F, L]. Dto. Santiago Juxtlahuaca. Mpio. Santiago Juxtlahuaca, 2 km de San Juan Piñas, carretera a la desviación para Coicoyán de las Flores-Santiago Juxtlahuaca. 17u149N 98u089O. 1745 m, 23 nov de 1994, Calzada 19514 (MEXU). [F, L]. 12) Vernonanthura hintoniorum (B.L. Turner) H. Rob., Phytologia 73 (2): 70. 1992. Tamaulipas. Mpio. Hidalgo, 33 km N de Adelaida. 24u099590N 99u219380O. 4 ago 1984, Mc Donald 623 (MEXU) [C, F, L]. 13) Vernonanthura liatroides (DC.) H. Rob., Phytologia 73(2): 71. 1992. Chihuahua. Mpio. Madera, El Agua Caliente, predio particular ‘‘El Chorrito’’. 2350 m, 17 oct 1990, Benı́tez 2920 (MEXU) [C, F, L]. Durango. Mpio. El Salto, El Arroyo de La Puerta, 5.5 km E de La Libertad, brecha al Huizache. 23u499N 105u379O. Secundaria de Pinus-Quercus, 1700 m, 9 mar 1985, Tenorio et al. 8186 (MEXU) [F, L]. Guanajuato. Mpio. Atarjea, El Charco, 8 km O de Atarjea. 1 500 m, 13 nov 1989, Ventura et al. 7617 (MEXU) [C, F, L]. Guerrero. Mpio. Eduardo Neri, Cañada Carrizalillo 2.5 km ESE de Amatitlan 17u519300N 99u449170O. 1625 m, 25 oct 1994, Cruz-Durán et al. 437 (MEXU) [F, L]. Mpio. Zirándaro, aprox. 6 km SE de Guayameo, por el camino a Placeres del Oro 18u159540N 101u129080O. 820 m, 18 nov de 1986, Villaseñor et al. 1073 (MEXU) [F, L]. Hidalgo. Mpio. Meztitlán. Parte alta de la barranca Ixcatlán. Ladera de exposición O, en la proximidad del paraje Mesa Grande, 2.5 km de la población del mismo nombre 20u399280N 98u479090O. 1960 m, 21 oct 2000, Guı́zar et al.5209 (MEXU) [C, F, L]. Nayarit. Mpio. Tepic, 15 km O de Tepic, sobre el camino a Jalcocotán 21u319120N 105u009360O. 800 m, 12 feb 1962, Rzedowski 15614 (MEXU) [C, F, L]. Mpio de Tepic, km5 de la terracerı́a al Cuarenteño que empieza 0.5 km O del Izote 21u309170N 104u589590O. 1460 m, 29 ene 1990, Téllez 12578 (MEXU) [F, L]. Oaxaca. Dto. Cuicatlán. Mpio. San Juan Bautista Cuicatlán, 4 km O de Coyula, camino a Santiago Quiotepec 17u559270N 96u569460O. 1339 m, 14 dic 2000, Martı́nez-Salas et al. 33431 (MEXU) [F, L]. Puebla. Mpio. Caltepec. Cerro El Tambor, NE de Caltepec 18u129010N 97u289090O. 1400 m, 10 oct 1984, Tenorio et al. 7642 (MEXU) [C, F, L]. Querétaro. 24 km NE de Landa, sobre la carretera a Xilitla. 1450 m, 12 dic 1988, Rzedowski 48053 (MEXU) [F, L]. Mpio. Landa, 2.5 km SE de El Humo. 1050 m, 14 nov 1988, Rubio 295 (MEXU) [F, L]. San Luis Potosı́. 15 mi O de Rı́o Verde. 7 oct 1976, Stuessy et al. 4064 (MEXU) [F, L]. 14) Vernonanthura oaxacana (Sch. Bip. ex Klatt) H. Rob., Phytologia 73(2): 72. 1992. Chiapas. Berriozábal, Las Vistas 16u489030N 93u159340O. 26 ene 1951, Enrı́quez 6845 (MEXU) [C, F, L]. Mpio. Cintalapa, 11 km N de Cintalapa, sobre la terracerı́a a Francisco I. Madero 16u459230N 93u459040O. 750 m, 28 ene 1990, Reyes-Garcı́a et al. 1467 (MEXU) [F, L]. Mpio. Motozintla, colonia [VOL. 139 Villa Hidalgo, aprox. 8 km NE de Motozintla, por la carretera a Frontera Comalapa 15u249470N 92u099200O. 1060 m, 21 mar 1992, Villaseñor et al. 1233 (MEXU) [F, L]. Oaxaca. 47 km NO de Jalapa del Marqués; aprox. 80 km NO de Tehuantepec, por la carretera a Oaxaca. 12 abr 1983, Villaseñor et al. 445 (MEXU) [F, L]. Dto. Ejutla. Mpio. Yogana. 27 dic 1978, Solano et al. 479 (MEXU) [F, L]. Dto. Juchitán. Mpio. Ixtepec, al N de Nizanda, llegando por la estación de ferrocarril. 13 ene 1988, Martı́nezRamı́rez 1185 (MEXU) [C, F, L]. Dto. Miahuatlán. Mpio. San Jerónimo Coatlán, Cañada de San Jerónimo, N de el poblado, siguiendo la corriente del rı́o, ca. 3 km 16u159N 96u539O. 1450 m, 29 jun 1992, Campos 4592 (MEXU) [C, F, L]. Dto. Pochutla. Mpio. San Miguel del Puerto, camino al Macahuite 15u56918.50N 96u259000O. 414 m, 25 feb 2002, Pascual 392 (MEXU) [F, L]. Mpio. San Miguel del Puerto, 1.5 km de Santa Marı́a Xadani a la carretera rumbo a San Miguel del Puerto 15u56950.70N 96u05917.10O. 490 m, 3 ene 2002, Pascual 289 (MEXU) [F, L]. Dto. Tehuantepec. Mpio. Santo Domingo Tehuantepec, Cerro Guiengola 11 km NO de Tehuantepec, carretera a Oaxaca 16u259N 95u229O. 900 m, 9 dic 1991, Campos 236 (MEXU) [F, L]. Mpio. Tehuantepec, El Sapotal, 37 km O de Tehuantepec, entrando por Pozo Zorrillo, el cual está 1 km NO de Tehuantepec 16u189N 95u259O. 2 dic 1987, Martı́nez-Ramı́rez 1138 (MEXU). [F, L]. 15) Vernonanthura patens (Kunth) H. Rob., Phytologia 73(2): 72. 1992 Guerrero. 5 km NE de Paraı́so, camino AtoyacPuerto del Gallo. 1000 m, 28 mar 1983, Soto et al., 5084 (MEXU) [C, F, L]. Hidalgo. Mpio. Tenango de Doria, 3 km E de Tenango de Doria, hacı́a Cirio. 1700 m, 20 may 1982, Hernández-Magaña 7320 (MEXU) [F, L]. Mpio. Zacualtipán, Tlahuelompa 2 km N. 24 abr 1995, Alcántara et al. 2042 (MEXU) [F, L]. Morelos. Cuernavaca. Ago-Sep, 1950, Lyonnet 39 (MEXU) [F, L]. Nayarit. 12 mi NE de San Blas 21u379310N 105u099210O. 60 m, 21 abr 1951, McVaugh 12072 (MEXU) [F, L]. Mpio. Tepic, km 15 de la carretera Tepic-Mazatlán 21u369360N 104u579220O. 630 m, 1 abr de 1994, Flores-Franco et al. 3359 (MEXU) [C, F, L]. Oaxaca. Dto. Yautepec. Mpio. Santa Marı́a Ecatepec, Rı́o Otate, S de Santa Marı́a Ecatepec 16u149N 95u559O. 800 m, 9 may 1993, Tenorio 18839 (MEXU) [F, L]. Puebla. Mpio. Pahuatlán. Xopanapa, 8 km SO de Pahuatlán 20u209N 98u559O. 1800 m, 22 may 1986, Tenorio et al. 11350 (MEXU) [F, L]. Querétaro. Mpio. Jalpan, al Oriente de Tanchanaquito, El Sabinito, 21u359090N 99u129460O. 400 m, 1 may 1992, López-Chávez 305 (MEXU) [F, L]. San Luis Potosı́. Mpio. San Luis Potosı́, Ciudad Santos, 21u369460N 98u589050O. 3 may 1979, Alcorn 2947 (MEXU) [C, F, L]. Veracruz. Mpio. Huatusco, km 2 del camino de terracerı́a Huatusco-Elotepec 19u109N 96u589O. 1300 m, 24 abr 1980, Avendaño et al. 787 (MEXU) [F, L]. Mpio. Hidalgotitlán, km 2–3 del camino Plan de Arroyos–Álvaro Obregón 17u159N 94u409O. 130 m, 12 abr de 1974, Brigada 2742 (MEXU) [F, L]. Mpio. San Andrés Tuxtla. Laguna Azul, 0.5 km N del lote 71 de la Estación de Biologı́a Tropical ‘‘Los Tuxtlas’’ 18u349N 95u049O. 200 m, 16 may 1989, Ibarra et al. 3366 (MEXU) [F, L]. 2012] REDONDA-MARTÍNEZ ET AL.: TRICHOMES IN MEXICAN VERNONIEAE 16) Vernonanthura serratuloides (Kunth) H. Rob., Phytologia 73 (2): 73. 1992. Chihuahua. Mpio. Moris. Moris. 700m, 29 sep 1985, Tenorio et al., 10062 (MEXU) [F, L]. Durango. Mpio. Otaez. Cercanı́a al rancho La Lechuga, camino al rı́o Otaez. 1500 m, 3 oct 1990, Benı́tez 2574 (MEXU) [C, F, L]. Guanajuato. Mpio. Acámbaro, cerca de Acámbaro, sobre la carretera que va a Zinapécuaro. Pastizal secundario, 30 oct 1987, Dı́azBarriga 4449 (MEXU) [C, F, L]. Jalisco. Mpio. Colotlán, 8 km SO de Colotlán 22u039000N 103u169340O. 1700 m, 8 oct 1981, Vázquez 702 (MEXU) [F, L]. Michoacán. 4 km S de Tuxpan, carretera Zitácuaro-Morelia. 1700 m, 12 nov 1979, Soto 1990 (MEXU) [F, L]. Nayarit. Mpio. La Yesca, 6.2 km SE de Puente Camotlán, camino a Huajimic 21u369N 104u049O. 1222 m, 26 oct 1989, Tenorio et al. 16649 (MEXU) [F, L]. Sinaloa. Mpio. Badiraguato, O de Villa de Huixiopa, NE del km 98.4 de la 247 carretera 24 México-Badiraguato 25u459220N 107u119290O. 880 m, 29 oct 1996, Yahara et al. 754 (MEXU) [C, F, L]. Mpio. Badiraguato, Santiago los Caballeros, 5 km adelante de Santiago los Caballeros 25u349550N 107u219250O. 1250 m, 2 oct 1998, Hernández 768 (MEXU) [F, L]. Sonora. Álamos, Rı́o Fuerte. Bosque, 19 oct 1936, H. S. Gentry 2932 (MEXU) [F, L]. Mpio. Yecora, cerca del cerro La Laguna ca. de San Nicolás, km 251 de la carretera México-Ciudad Obregón, 28u239370N 109u059310O. 1400 m, 3 oct 1998, Van Devender et al. 98-2012 (MEXU) [F, L]. Zacatecas. Mpio. Jalpa, 21u399210N 102u539340O. Carretera a Tlachichila, aprox. 1.5 km S del entronque con la carretera Jalpa–Aguascalientes. 1650 m, 18 de oct 1997, Balleza et al. 7549 (MEXU) [C, F, L]. Mpio. Trinidad Garcı́a de la Cadena, carretera a Guadalajara, aprox. 2 km S de la Ciudad de Garcı́a de la Cadena 21u119460N 103u279490O. Pastizal, 1890 m, 9 oct 1997, Balleza 7312 (MEXU) [F, L].