European Journal of Taxonomy 834: 22–37 https://doi.org/10.5852/ejt.2022.834.1895 ISSN 2118-9773 www.europeanjournaloftaxonomy.eu 2022 · Barberá P. et al. This work is licensed under a Creative Commons Attribution License (CC BY 4.0). Research article A new species of Paranecepsia (Euphorbiaceae-Acalyphoideae) from Madagascar and its relationships among the ‘alchorneoids clade’ Patricia BARBERÁ 1,* , Olivier LACHENAUD 2 & Ricarda RIINA 3 1 Africa & Madagascar Department, Missouri Botanical Garden, P.O. Box 299, 63166-0299, St. Louis, Missouri, USA. 2 Meise Botanic Garden, Nieuwelaan 38, B-1860 Meise, Belgium. 2 Herbarium et Bibliothèque de Botanique africaine, CP 265, Université Libre de Bruxelles, Boulevard du Triomphe, B-1050 Brussels, Belgium. 3 Real Jardín Botánico (RJB), CSIC, Plaza de Murillo 2, 28014, Madrid, Spain. * 2 Corresponding author: pbarbera@mobot.org Email: olivier.lachenaud@plantentuinmeise.be 3 Email: rriina@rjb.csic.es Abstract. The formerly monotypic genus Paranecepsia Radcl.-Sm. is expanded with the description and illustration of a second species, Paranecepsia andrafiabensis Barberá & O.Lachenaud sp. nov. Molecular phylogenetic analyses of plastid rbcL and trnL-F data confirm a sister relationship between the new species and P. alchorneifolia Radcl.-Sm., as members of the alchorneoids clade. Paranecepsia andrafiabensis sp. nov. is notable for expanding the character states for the genus (now including both 2- and 3-locular ovary species) and broadening the geographic range of the genus from continental Africa to Madagascar. The new species adds to the diverse karst limestone endemics of northwestern Madagascar, where it has a very restricted distribution at the base of the western wall of the Ankarana tsingy. An amended generic description of Paranecepsia and a key to the species are also presented. Paranecepsia andrafiabensis sp. nov. is provisionally assessed as VU D1 based on the IUCN Red List criteria. Keywords. Alchorneeae, Ankarana, Africa, Madagascar, tsingy. Barberá P., Lachenaud O. & Riina R. 2022. A new species of Paranecepsia (Euphorbiaceae-Acalyphoideae) from Madagascar and its relationships among the ‘alchorneoids clade’. European Journal of Taxonomy 834: 22–37. https://doi.org/10.5852/ejt.2022.834.1895 Introduction Euphorbiaceae Juss. in the strict sense (excluding Phyllanthaceae Martinov, Picrodendraceae Small, Putranjivaceae Meisn. and Peraceae Klotzsch) is a highly diverse family with about 230 genera and more than 6300 species. It includes some of the largest genera of flowering plants like Euphorbia L. and Croton L., but most genera have only few species, including more than 120 genera with 1 to 3 species. These small genera are often poorly understood and, in most cases, known from sparse and/ or incomplete collections. An example of one such genus is Paranecepsia Radcl.-Sm. (Radcliffe22 BARBERÁ P. et al., New species of Paranecepsia from Madagascar Smith 1987). This African genus was described based on specimens with staminate flowers and fruit (Radcliffe-Smith 1975) as a monotypic, dioecious group characterized by its conspicuous leaf stipels, staminate flowers with an accrescent calyx and apiculate anthers, and 3-lobed fruits (Radcliffe-Smith 2001). The type species, Paranecepsia alchorneifolia Radcl.-Sm., is a small tree of riverine forests occurring in northeastern Mozambique and southern Tanzania. The pistillate flowers of Paranecepsia were originally unknown, causing subsequent misinterpretation of floral details inferred from the fruits (i.e., 5–7 unequal sepals and no petals indicated in Radcliffe-Smith 1987, 2001), which were later amended by Vorontsova & Hoffmann (2007) based on a petaliferous flowering pistillate specimen from Tanzania collected in 2001. As its name suggests, Paranecepsia has morphological similarities with Necepsia Prain, with both genera included in tribe Bernardieae G.L.Webster (Webster 1994; RadcliffeSmith 2001) or Pycnocomeae subtribe Necepsinae G.L.Webster (Webster 2014). Previous molecular phylogenetic analyses of Euphorbiaceae using a comprehensive sampling of genera (Wurdack et al. 2005; Tokuoka 2007) have shown that Paranecepsia alchorneifolia is part of the informally recognized ‘alchorneoids’ clade, a group partially supported by morphological data (Wurdack et al. 2005). Paranecepsia alchorneifolia was included by Wurdack et al. (2005) in the rbcL analysis, where it was recovered sister to Pseudagrostistachys Pax & K.Hoffm. In the combined analysis (rbcL + trnL-F), the authors excluded Paranecepsia, but Pseudagrostistachys was recovered at the most basal node of the alchorneoids (Wurdack et al. 2005). Madagascar is a major hotspot of diversity and endemism for plants in general and for Euphorbiaceae in particular. Approximately 44 genera and 478 species of Euphorbiaceae s. str. (Madagascar Catalogue 2022) have been recorded from this country, and new species from different genera continue to be described every year (e.g., Kainulainen et al. 2017; McPherson 2017, 2019; Castillon & Castillon 2018; Montero-Muñoz et al. 2020, 2022; Haevermans & Hetterscheid 2021). The family occurs all over Madagascar but is especially well represented in dry areas, and especially in the limestone karsts formations named ‘tsingys’ that form large massifs in the west of the island and harbour many endemic species. While studying unidentified Euphorbiaceae specimens from Madagascar in 2018, the second author discovered two fruiting collections that did not match any genus recorded from the island, and reminded him of the East African Paranecepsia, although their fruits were bilocular (instead of trilocular). Both collections were made in 1969 at the base of the Ankarana tsingy wall by R. Capuron and P. Morat, and their discovery spurred a recent expedition in November 2019 to the western part of Ankarana National Park to search for flowering material of this plant. Morphological features of the resulting new collections confirmed that they represented an undescribed species of Paranecepsia, which clearly broadened the generic concept for that genus (notably for locule ovary number) and extended its distribution from continental Africa to Madagascar. We describe this new species herein and present an expanded description of genus Paranecepsia. In addition, we generated sequence data from the plastid rbcL and trnL-F regions for the new species to verify its generic placement and provide a phylogenetic framework, further refining relationships within the alchorneoids clade. Material and methods The work is based on a study of herbarium material from BR, COI, DSM, K, MA, MO, NHT, P, TAN and TEF, flowers preserved in spirit, and field observations. Acronyms of herbaria follow Index Herbariorum (Thiers continuously updated). Most of the specimens have been seen. For the phylogenetic analysis, silica gel dried leaf samples of the new Paranecepsia were extracted following the CTAB protocol (Doyle 1991). The trnL-F region was amplified using the same primers as in Silva et al. (2020). The rbcL region was sequenced using the following sets of primers: rbcLaf (ATG23 European Journal of Taxonomy 834: 22–37 (2022) TCA-CCA-CAA-ACA-GAG-ACT-AAA-GC) and rbcLar (GTA-AAA-TCA-AGT-CCA-CCR-CG); rbcL1f (ATG-TCA-CCA-CAA-ACA-GAR-AC) and rbcL724r (TCG-CAT-GTA-CCC-TGC-AGTTGC); rbcL427f (GCT-TAT-AAA-ACT-TTC) and rbcL1368r (CTT-TCC-AAA-TTT-CAC-AAG-CAGCA); rbcL628f (CCA-TTT-ATG-CGT-TGG-AGA-GAY-CG) and 1360r (CTT-CAC-AAG-CAG-CAGCTA-GTT-C). Polymerase chain reaction (PCR) amplification and sequencing followed the laboratory procedures described in Masa-Iranzo et al. (2021). Nucleotide sequences for each genetic region were assembled and edited in Geneious Prime ver. 2019.0.3 (Biomatters Ltd, Auckland, New Zealand). The new sequences (trnL-F/rbcL) were first analysed using the Basic Local Alignment Search Tool (BLAST) available at the National Center for Biotechnology Information (NCBI) website to verify their closet similarity to members of Acalyphoideae Beilschm. and more specifically to members of the alchorneoids clade, as suggested by morphological features. The BLAST search was conducted using NCBI default parameters. Based on the results of the BLAST search (i.e., the new species was most similar to either sequences of Paranecepsia or Necepsia in GenBank), we built a dataset of 26 samples including all the available sequences of member of the alchorneoids clade and their most closely related taxa according to the phylogenetic analyses of Wurdack et al. (2005). We also included two species (Cheilosa montana Blume and Neoscortechinia kingii (Hook.f.) Pax & K.Hoffm.) from subfamily Cheilosoideae K.Wurdack & Petra Hoffm., to serve as most distant outgroup. All sequences, except the ones of the new species (three samples, six sequences), were downloaded from GenBank (Appendix 1); most of them have been generated in the context of Euphorbiaceae studies (e.g., Wurdack et al. 2005; Kulju et al. 2008; Cervantes et al. 2016; van Welzen et al. 2020). Bayesian MCMC analyses were implemented in MrBayes ver. 3.2.6 (Ronquist et al. 2012), with 2 concurrent runs, each with 4 chains and sampling every 1000 generations over 10 000 000 generations, a 0.2 temperature coefficient. The substitution models HKY+G and GTR+I+G were selected for the trnL-F and rbcL markers, respectively, using the Akaike information criterion in jModelTest ver. 2.1.6 (Guindon & Gascuel 2003; Darriba et al. 2012). Tracer ver. 1.7.1 was used to check convergence and mixing of the Markov chains (Rambaut et al. 2014). A 50% majority-rule consensus tree was built after discarding the first 25% of samples (burn-in). Geographical data were used to make a distribution map for the two species of Paranecepsia with ArcView GIS ver. 3.2. for Windows. A preliminary assessment of conservation status using the IUCN categories and criteria (IUCN 2019) is provided for the new species. The geographical parameters of Area of Occupancy (AOO) and Extent of Occurrence (EOO), were calculated with GeoCAT (Bachman et al. 2011) using a 2 × 2 km grid. Results Phylogenetic relationships The three accessions of the new species of Paranecepsia have identical sequences within each locus. The trnL-F sequences were most similar to Necepsia afzelii Prain (97.88% identity, 100% of query cover) and the rbcL sequences to Paranecepsia alchorneifolia (99.71% identity, 100% of query cover). In the phylogenetic analysis, the sequences of the new species were recovered monophyletic with high posterior probability (PP = 1), and sister in turn to Paranecepsia alchorneifolia (PP = 0.94) (Fig. 1). This clade was sister to the Necepsia-Pseudagrostistachys clade (PP = 9.98); both clades form the two main lineages, clades A and B (Fig. 1), of the alchorneoids (PP = 1). Alchorneeae s. str. excluding Mareyopsis Pax & K.Hoffm. formed a strongly supported (PP = 1) monophyletic group that was nested in a polytomy with other members of the alchorneoids (Fig. 1). 24 BARBERÁ P. et al., New species of Paranecepsia from Madagascar       
    

  

  

 Fig. 1. Phylogenetic relationships of representatives of the alchorneoids clade within EuphorbiaceaeAcalyphoideae, including samples of the new species. Bayesian 50% majority-rule consensus tree based on the combined 2-marker, 26-tip dataset with posterior probability values indicated at nodes. Note: the name Conceveiba terminalis (Baill.) Müll.Arg. is used in place of Gavarretia terminalis Baill. in Wurdack et al. (2005). Taxonomic treatment Class Magnoliopsida Brongn. Order Malpighiales Mart. Family Euphorbiaceae Juss. Genus Paranecepsia Radcl.-Sm. Kew Bulletin 30: 684 (Radcliffe-Smith 1975 publ. 1976), here amended. Type species Paranecepsia alchorneifolia Radcl.-Sm., Kew Bulletin 30: 684 (Radcliffe-Smith 1975 publ. 1976). 25 European Journal of Taxonomy 834: 22–37 (2022) Description Dioecious shrubs to medium-sized trees up to 15 m high, very ramose with Terminalia-like branching (Aubréville’s model); bark greyish. Indumentum of simple trichomes. Buds perulate. Stipules subulate, tardily caducous. Leaves deciduous, alternate, spirally arranged, clustered near apices of twigs and interspersed with bud scales, simple, petiolate, stipellate or not; vernation involute; leaf blade oblanceolate to elliptic, shallowly serrate or crenate-serrate with glandular teeth; venation pinnate, midrib prominent above, lateral veins 10–16 pairs, tertiary veins scalariform to reticulate; domatia present as hairy tufts in the axils of the secondary veins; basilaminar glands present or absent. Inflorescences racemose (strongly reduced in P. andrafiabensis sp. nov.), axillary, solitary; the staminate ones with 1–5 flowers per bract; the pistillate ones with 1–2 flowers; bracts small, subulate. Staminate flowers with pedicel articulate; calyx closed in bud, later splitting into 3–5 valvate lobes which become reflexed; petals absent; stamens 20–40, glabrous, with filaments free, anthers 2-locular, dorsifixed, introrse, thecae pendulous and longitudinally dehiscent, connective not enlarged; receptacle subglobose; disk glands free, interstaminal, numerous, forming a raspberry-like structure; pistillode absent. Pistillate flowers long-pedicellate; pedicels articulate; sepals 5, free, slightly unequal, elliptic to obovate, entire, foliaceous and prominently veined, green, persistent and slightly accrescent in fruit; petals 5, free, alternisepalous, linear to oblanceolate, entire, glabrous, similar in colour and texture to the sepals but much smaller and with hardly prominent venation; staminodes 1–10, sometimes absent; disc annular to slightly undulate, glabrous; ovary sessile, 2 or 3 locular, with strigose indumentum; ovules 1 per locule; styles bifid, connate at base, persistent; stigmas shortly frimbriate. Fruits capsular, 2 or 3 lobed, pubescent, dehiscent in 2 or 3 bivalved mericarps (cocci); endocarp thinly woody; columella persistent. Seeds globose, smooth, ecarunculate and exarillate, testa plain brown or mottled, hilum ellipsoid to narrowly oblong. Key to the species of Paranecepsia 1. Leaves with petioles 0.2–0.8 cm long and stipels 2.5–5 mm long; staminate inflorescences up to 9 cm long; pistillate flowers with sepals 5–9 mm long; ovary 3-locular; fruits 5–6 × 10 mm; seed coat plain brown ........................................................................Paranecepsia alchorneifolia Radcl.-Sm. ‒ Leaves with petioles 0.6–2.6 cm long and stipels (if present) 1–2.2 mm long; staminate inflorescences up to 1.3 cm long; pistillate flowers with sepals 9–15 mm long; ovary 2-locular; fruits 7–8 × 13 mm; seed coat mottled ............................Paranecepsia andrafiabensis Barberá & O.Lachenaud sp. nov. Paranecepsia alchorneifolia Radcl.-Sm. Kew Bulletin 30: 684 (Radcliffe-Smith 1975 publ. 1976). Material examined Type MOZAMBIQUE ‒ Niassa Province • into a forest gallery of a dried stream, at side of the road NegomanoMueda, ca 30 km N of Chomba; 11°20′ S, 38°30′ E; 11 Nov. 1959; staminate fl.; A. Gomes e Sousa 4514; holotype: K[K000425585], K[K000425586] (image!); isotypes: COI[COI00077121], COI[COI00077122] (image!), EA n.v., LISC[011861], PRE[PRE0659451-0] (image!), SRGH[SRGH0106464-0] (image!). Note: the holotype consists of two sheets with cross labelling as “sheet 1” and “sheet 2”, both with a “holotype” annotation in A. Radcliffe-Smith’s handwriting, and they should be taken to constitute a single specimen according Turland et al. (2018, Art. 8.3). There are several variations of the type collection label, the most specific of which is typewritten in Portuguese on COI[COI00077121] and indicates “Á beira de um rio seco, a poucos metros da ponte da estrada Mueda-Negomano, cerca de 30 kms oeste de Chomba [On the edge of a dry river, a few meters from the Mueda-Negomano highway 26 BARBERÁ P. et al., New species of Paranecepsia from Madagascar Fig. 2. Distribution of the genus Paranecepsia Radcl.-Sm. in east Africa and Madagascar. Paranecepsia alchorneifolia Radcl.-Sm. (circles), Paranecepsia andrafiabensis Barberá & O.Lachenaud sp. nov. (square). 27 European Journal of Taxonomy 834: 22–37 (2022) bridge, about 30 kms west of Chomba], 11°20′ S, 38°30′ E. The label coordinates are clearly very inaccurate (in Tanzania, ca 100 km from Chomba) but from Google Earth imagery the closest match to this bridge locality is 36 km NNW of Chomba at 11°15′49.54″ S, 39°10′55.09″ E, in an area presently very degraded by agricultural activity. Other material MOZAMBIQUE ‒ no locality; 4 Apr. 1960; sterile; A. Gomes e Sousa 4514A; COI, K, LISC[011862]. ‒ Maputo Province • gallery of the river Ridi, westwards Porto Amélia town; 12°55′ S, 40°15′ E; alt. 15 m; 1 Oct. 1964; sterile; A. Gomes e Sousa 4831; BR, COI, K. – Cabo Delgado Province • Macondes, andados 30 km de Chomba para Negomano, ao longo do rio Matiu; alt. 300 m; 13 Apr. 1964; sterile; A.R. Torre & J. Paiva 11880; LISC. TANZANIA ‒ Lindi Region • Nanjilinji Division, Likawage Ward, ca 6 km E of Liwiti Village, Dagano ya Kiyenje na Mavunji [Junction of Ndagano and Mavuji Rivers]; 9°7′ S, 39°10′ E; alt. 60 m; 14 Nov. 2005; staminate fl.; C.J. Kayombo, P. Ezrom, H. Makelele and A. Mabruki 5203; MO[5940755] • Namatimbili Forest; alt. 250 m; 26 Nov. 2001; pistillate fl.; F. Mbago and B. Mpanda 2244; K. ‒ Morogoro Region • Kilombero Game Control Area; alt. 300 m; 2 Nov. 1998; fruit; A.S. Mkeya and P. Metele 1062; MO[5677723], NHT • ibid.; staminate fl.; A.S. Mkeya and P. Metele 1063; K, MO[6575002], NHT • Kilombero Game Control Area (near Mofu village); alt. 550 m; 4 Oct. 1998; pistillate fl.; H.O. Suleiman/ Frontier team 934; DSM • Selous Game Reserve, Kigombe River; alt. 430 m; Nov. 1970; fruit; A.F. Rees T56; K • Vigade, Kidodi, Kilosa District; Nov. 1952; staminate fl.; S.R. Semsei 1046; K • Selous Game Reserve, Mlahi; 8°17′ S, 37°05′ E; alt. ca 275 m; 15 Oct. 1975; sterile; K.B. Vollesen MRC 2838; DSM, WAG • Selous Game Reserve, Lukula; ca 9°30′ S, 36°50′ E; 19 Nov. 1976; fruit; K.B. Vollesen MRC 4128; DSM, K • Selous Game Reserve, ca 4 km E of Mlahi; 8°17′ S, 37°07′ E; 31 Oct. 1977; staminate fl.; K.B. Vollesen MRC 4746; DSM, K. Distribution, habitat, and phenology Paranecepsia alchorneifolia is only known from southern Tanzania and northern Mozambique (Fig. 2), in gallery forest, bush savannah, and wooded grassland, between 15 and 550 m. Flowering specimens were collected in October and November, and fruiting ones in November. Paranecepsia andrafiabensis Barberá & O.Lachenaud sp. nov. urn:lsid:ipni.org:names:77302734-1 Figs 3–6 Diagnosis Paranecepsia andrafiabensis sp. nov. is morphologically similar to P. alchorneifolia, but differs from it mainly by having longer petioles (0.6–2.6 vs 0.3–0.8 cm long), stipels shorter or absent (1–2.2 mm when present vs 2.5–5 mm long, always present), shorter staminate inflorescences (< 1.3 cm vs 4.5–9 cm long), pistillate flowers with longer sepals (9–15 mm vs 5–9 mm long), bilocular ovary (vs trilocular), and seed coat mottled with dark and pale brown (vs uniformly brown). Etymology The specific epithet refers to the type locality, Andrafiabe village, at the western border of the Ankarana tsingy. Material examined Type MADAGASCAR ‒ Diana Region • Ambilobe, Andrafiabe, at the base of the wall of Ankarana; 12°55′40″ S, 49°03′41″ E; alt. 66 m; 21 Nov. 2019; pistillate fl.; P. Barberá, P. Antilahimena, J. Razanatsoa and S. Andriazafy 2770; holotype: MO-6956134; isotypes: BR, P, TAN. 28 BARBERÁ P. et al., New species of Paranecepsia from Madagascar Paratypes MADAGASCAR ‒ Diana Region • Andrafiabe, PM 200 from the camp, on the circuit to Grotte de Andrafiabe; 12°55′55″ S, 49°03′29″ E; alt. 72 m; 21 Nov. 2019; pistillate fl.; P. Barberá, P. Antilahimena, J. Razanatsoa and S. Andriazafy 2764; BR, MA, MO, P, TAN • ibid.; staminate fl.; P. Barberá, P. Antilahimena, J. Razanatsoa and S. Andriazafy 2765; BR, MO, P, TAN • ibid.; offshoot; P. Barberá, P. Antilahimena, J. Razanatsoa and S. Andriazafy 2767; BR, MO, P, TAN • Andrafiabe, at the base of the wall of Ankarana; 12°55′40″ S, 49°03′41″ E; alt. 66 m; 21 Nov. 2019; staminate fl.; P. Barberá, P. Antilahimena, J. Razanatsoa and S. Andriazafy 2769; BR, MA, MO, P, TAN • ibid.; 12°55′38″ S, 49°03′45″ E; alt. 49 m; 21 Nov. 2019; pistillate fl.; P. Barberá, P. Antilahimena, J. Razanatsoa and S. Andriazafy 2771; BR, MO, P, TAN • ibid.; 12°55′51″ S, 49°03′32″ E; alt. 48 m; 21 Nov. 2019; pistillate fl.; P. Barberá, P. Antilahimena, J. Razanatsoa and S. Andriazafy 2772; BR, MO, P, TAN • ibid., 12°56′08″ S, 49°03′22″ E; alt. 37 m; 23 Nov. 2019; pistillate fl.; P. Barberá, P. Antilahimena, J. Razanatsoa and S. Andriazafy 2797; BR, MO, P, TAN • ibid., 12°56′08″ S, 49°03′20″ E; alt. 38 m; 23 Nov. 2019; pistillate fl.; P. Barberá, P. Antilahimena, J. Razanatsoa and S. Andriazafy 2798; BR, MA, MO, P, TAN • ibid.; 12°56′05″ S, 49°03′23″ E; alt. 62 m; 23 Nov. 2019; staminate fl.; P. Barberá, P. Antilahimena, J. Razanatsoa and S. Andriazafy 2799; BR, MO, P, TAN • à la base du mur de l’Ankarana; 16–28 Jan. 1969; fr.; Service Forestier (R. Capuron) 28711_SF; BR[0000025668131V], G, K, MO[6911563], P[05570467], TEF • forêt au pied de la falaise de l’Ankarana; Jan. 1969; fr.; P. Morat 3054; MO[5990069], P[05570468], P[05570469], P[05570470], P[05570471], TAN. Description Medium sized tree, 5–15 m high, 14–40 cm DBH; bark smooth when young, with numerous warty lenticels, gray; older bark scaly forming small or medium-sized loosely attached plates; twigs cylindrical, glabrous, soon woody with pale buff-grey bark. Bud scales triangular to ovate, 2–5.5 × 0.7–2 mm, apex acuminate to very long acuminate, glabrous to densely pubescent on both faces. Stipules linear-lanceolate, 3–8 mm long, caducous, densely pubescent with simple trichomes to 0.8 mm long. Leaves with petiole 0.6–2.6 cm long, canaliculate above and obscurely bipulvinate, eglandular, glabrous to puberulous, trichomes sometimes confined to upper side of petiole in the older leaves; leaf blade elliptic to oblanceolate, 4–15.5 × 1.2–5.5 cm long; chartaceous to papyraceous, glabrous above, below with scattered short simple trichomes on the midrib and domatia present as hairy tufts in the axils of the secondary veins; midrib prominent above and more strongly so below; secondary veins 10–13 pairs, prominent on both sides, strongly ascending and irregularly arching near the margin; tertiary veins scalariform, prominent and rather dense beneath; quaternary veins very densely reticulate forming small squares, only visible with hand lens; base rounded to subcordate; apex acute to acuminate, sometimes rounded, and rarely emarginate; margin serrate with 20–30 glandular teeth per side; leaf glands absent, or 1–4(–5) present near the base of the lamina on the lower surface, rarely reaching upper parts of the leaf, flat, elliptic to rounded, 0.3–0.6 × 0.2–0.3 mm; stipels setaceous, 1–2.2 × 0.1– 0.15 mm, glabrous, inserted on the petiole distinctly below the blade insertion, erect, sometimes absent. Staminate inflorescences up to 1.3 cm long; axis slightly pubescent or with scattered trichomes, bearing up to 3 bracts and (1–)2–6 flowers and 1–3(–5) flowers per bract; bracts ovate to lanceolate, sometimes oblong, 2–3 × 1–1.5 mm, acute, densely pubescent outside, glabrous inside; bracteoles 1 per pedicel, linear, ca 1 × 0.2 mm, sparsely pubescent outside, sometimes absent. Staminate flowers with pedicel 3–5.5 mm long, jointed 1–2 mm from the base; bud subglobose, 1.8 mm in diameter, pubescent, greenish; calyx lobes 3–5, ovate-lanceolate, 2.7–4.8 × 0.4–2.5 mm, acute to shortly acuminate, papyraceous, appressed-pubescent outside at least towards apex, glabrous inside, yellowish to greenish; stamens 20–33, filaments 2–3.5 mm long, greenish, anthers 0.4–0.7 mm long, yellowish, thecae elliptic, connective minutely apiculate; disk glands elongated, glabrous, greenish. Pistillate inflorescences 1(–2)-flowered, axis glabrous; bract very narrowly lanceolate, 1.1–3 × 0.2–0.3 mm, acute, pubescent. Pistillate flowers with pedicel 0.6–1.6 cm long, articulate (0.1–)0.4–1 cm from the bract; sepals 4–5, separate from each other, slightly unequal in size, narrowly elliptic or elliptic to oblanceolate, sometimes oblong, 7–15 × 2–6(–7) mm, papyraceous, glabrous inside, sparsely pilose on the central part outside, hairy apically, conspicuously veined, apex acute to acuminate, 29 European Journal of Taxonomy 834: 22–37 (2022) Fig. 3. Illustration of Paranecepsia andrafiabensis Barberá & O.Lachenaud sp. nov. a. Branch with pistillate flower. b. Bud. c. Leaf base with stipels. d. Detail of the lower leaf surface with domatia. e. Leaf margin. f. Staminate inflorescence. g. Staminate flower. h. Stamen. i. Pistillate flower. j. Petal of pistillate flower. k. Ovary and stigmas, lateral view. l. Fruit with persistent calyx, lateral view. m. Fruit, top view. n. Seed, lateral view. From Barberá et al. 2797 (a–b), Capuron SF-28711 (c–e, l–n), Barberá 2799 (f), Barberá et al. 2765 (g–h), Barberá et al. 2771 (i), Barberá et al. 2798 (j), Barberá et al. 2764 (k). Drawn by O.Lachenaud. 30 BARBERÁ P. et al., New species of Paranecepsia from Madagascar rarely rounded, margins entire; petals (1–)2–5, unequal, linear or narrowly elliptic to narrowly oblanceolate, (0.2–)0.6–5(–5.4) × (0.05–)0.1–0.8(–1.2) mm, acute, glabrous, yellowish to greenish; staminodes 1 or absent, extending to the same length as the disc, basally terete, apically enlarged; disc 1.8–2.6 mm wide, yellowish to greenish, glabrous; ovary 2-locular, 2–4.2 × 3.5–7.3(–8.3) mm, greenish-yellowish; styles 2, 2.5–3.2 mm long, connate, pilose, greenish, stigmas bifid, shortly fimbriate. Fruits strongly bilobed, 7–8 × 13 × 7.5 mm, Fig. 4. Field photographs of Paranecepsia andrafiabensis Barberá & O.Lachenaud sp. nov. a. Forest of Paranecepsia andrafiabensis. b. Old trunk. c. Seedlings. d. Detail of old tree trunk. e. Detail of young tree trunk. From Barberá et al. 2769 (b, d), Barberá et al. 2767 (c), Barberá et al. 2798 (e). Photos by P. Barberá. 31 European Journal of Taxonomy 834: 22–37 (2022) minutely tuberculate, covered with a dense rufous puberulous indumentum, and with sparse longer whitish trichomes ca 0.2 mm long (one at the top of each tubercle), brownish when dry; pedicel 1.4–1.9 cm long; calyx and petals persistent; columella ca 5 mm long; seeds globose, ca 6 × 6 mm, testa mottled with dark and pale brown, hilum broadly ellipsoid, ca 2.2 × 2 mm. Distribution, habitat, and phenology Paranecepsia andrafiabensis sp. nov. is only known from the dry, deciduous forest on karstic limestone (‘tsingy’) that surrounds part of the base of the western wall of the Ankarana tsingy, in northwestern Madagascar, at elevations between 37 and 72 m. The flowering material of this species was collected in November and the fruiting one in January. Fig. 5. Field photographs of Paranecepsia andrafiabensis Barberá & O.Lachenaud sp. nov. a. Bud. b. Domatial hair tufts at primary-secondary vein junctions. c. Leaf base and stipule. d. Stipels. From Barberá et al. 2767 (a, c–d), Barberá et al. 2765 (b). Photos by P. Barberá. 32 BARBERÁ P. et al., New species of Paranecepsia from Madagascar Preliminary conservation assessment Paranecepsia andrafiabensis sp. nov. is endemic to northwestern Madagascar where it grows at the base of the western wall of the Ankarana tsingy. It is presently known from 11 herbarium specimens, two of them collected in fruit by Morat and Capuron in 1969, and recently (in 2019) several collections with Fig. 6. Field photographs of Paranecepsia andrafiabensis Barberá & O.Lachenaud sp. nov. a. Staminate inflorescence. b. Pistillate inflorescence. c. Detail of the bract of the pistillate flower. d. Pistillate flower, lateral view. e. Pistillate flower, top view. From Barberá et al. 2799 (a), Barberá et al. 2765 (b–c), Barberá et al. 2771 (d), Barberá et al. 2772 (e). Photos by P. Antilahimena (a) and P. Barberá (b–e). 33 European Journal of Taxonomy 834: 22–37 (2022) flowers and fruits were made at east of Andrafiabe village. All the collections represent seven occurrences and only one subpopulation of the species. We have verified that the species is abundant at this site with many seedlings and mature trees. Based on a 2 × 2 km cell size, the AOO is estimated as 4 km2, which is less than the upper threshold for “Critically Endangered” status under Criterion B2. The EOO is the same as the AOO. All known occurrences are located at the limits of a protected area (Ankarana National Park), and no specific threats have been identified at the present time. However, we estimate that the population size is less than 1000 mature individuals, and that the species presumably has a low dispersal ability. For these reasons, Paranecepsia andrafiabensis is assigned a preliminary status of VU D1. Notes The stipels at the base of the leaf blade are present on some specimens and absent in others, even on very young leaves; this appears to be individual variation. Discussion The addition of Paranecepsia brings the number of native Malagasy genera of Euphorbiaceae to 40 (5 alchorneoids), which contain over 450 species (14+ alchorneoids) (Madagascar Catalogue 2022). The other genera of alchorneoids in Madagascar include Alchornea Sw., Amyrea Leandri, Orfilea Baill., and Necepsia. Our phylogenetic reconstruction verifies the placement of the new species within the genus Paranecepsia and, as expected, shows similar relationships within the alchorneoids and related lineages as in Wurdack et al. (2005), including the paraphyletic position of the two Alchornea species sampled. The alchorneoids consist of 12–15 genera and ca 120 species that are currently classified in tribes Alchorneeae (Hurus.) Hutch., Agrostistachydeae (Müll.Arg.) G.L.Webster, Caryodendreae G.L.Webster, and Pycnocomeae Hutch. (Webster 2014). As suggested by Wurdack et al. (2005), the supported nodes of sister taxa indicate that Alchorneeae s. str. might be expanded to include the members of the alchorneoid clade. Potential synapomorphies in wood anatomy (Hayden & Hayden 2000; Wurdack et al. 2005) and in pollen (Nowicke & Takahashi 2002; Wurdack et al. 2005) have been indicated by previous authors supporting Alchorneeae s. str. within the alchorneoids. Further morphological studies and phylogenetic analyses need to be done, using more phylogenetically informative genetic regions and a broader taxon sampling within this clade, including a larger representation of its largest genus (Alchornea), needed to better understand the phylogenetic structure within the alchorneoids. However, our analysis expands the generic members of this clade confirming Paranecepsia, which, although previously sampled in Wurdack et al. (2005), was only represented by a single rbcL sequence of Paranecepsia alchorneifolia. Acknowledgements We wish to thank the botanists of the Missouri Botanical Garden’s Madagascar Program for their assistance in organizing the fieldtrip and specimen management, especially Faranirina Lantoarisoa, Sylvie Andriambololonera, Patrice Antilahimena, and Christian Camara. Field work was conducted under the collaborative agreements between the Missouri Botanical Garden and the Parc Botanique et Zoologique de Tsimbazaza, and the Ministère de l’Environnement, de l’Écologie, de la Mer et des Forêts. The first author would like to express her special thanks to Patrice Antilahimena (MBG), Jacquie Razanatsoa (TAN), and Sehilany Andriazafy (our guide from Andrafiabe) for their great assistance in the field trip and specimen management. We gratefully acknowledge courtesies extended by the staff of Ankarana National Park. The fieldwork was conducted with support of the Krukoff funds from the Missouri Botanical Garden. The herbarium curators of COI, DSM, K, LISC, NHT, P, TAN and TEF are thanked for their assistance while working in their institutes. Support from project PID2019108109GB-I00, funded by MCIN/AEI/10.13039/501100011033/ and FEDER “A way to make Europe” is also acknowledged. 34 BARBERÁ P. et al., New species of Paranecepsia from Madagascar References Bachman S., Moat J., Hill A.W., de la Torre J. & Scott B. 2011. Supporting Red List threat assessments with GeoCAT: geospatial conservation assessment tool. ZooKeys 150: 117–126. https://doi.org/10.3897/zookeys.150.2109 Castillon J.P. & Castillon J.B. 2018. A new threatened species of Euphorbia sect. Goniostema (Euphorbiaceae) from northern Madagascar. Candollea 73 (2): 187–191. 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Molecular phylogenetic analysis of uniovulate Euphorbiaceae (Euphorbiaceae sensu stricto) using plastid rbcL and trnL-F DNA sequences. American Journal of Botany 92 (8): 1397–1420. https://doi.org/10.3732/ajb.92.8.1397 Manuscript received: 14 March 2022 Manuscript accepted: 26 May 2022 Published on: 8 August 2022 Topic editor: Frederik Leliaert Desk editor: Pepe Fernández Printed versions of all papers are also deposited in the libraries of the institutes that are members of the EJT consortium: Muséum national d’histoire naturelle, Paris, France; Meise Botanic Garden, Belgium; Royal Museum for Central Africa, Tervuren, Belgium; Royal Belgian Institute of Natural Sciences, Brussels, Belgium; Natural History Museum of Denmark, Copenhagen, Denmark; Naturalis Biodiversity Center, Leiden, the Netherlands; Museo Nacional de Ciencias Naturales-CSIC, Madrid, Spain; Real Jardín Botánico de Madrid CSIC, Spain; Leibniz Institute for the Analysis of Biodiversity Change, Bonn – Hamburg, Germany; National Museum, Prague, Czech Republic. Appendix 1. GenBank accession numbers for the rbcL, trnL-F sequences used in the phylogenetic analysis. Voucher information is provided for the new generated sequences of Paranecepsia andrafiabensis Barberá & O.Lachenaud sp. nov. Alchornea cordifolia (Schumach.) Müll.Arg., AY794959, AY7947. Alchornea latifolia Sw., HM446755, HG971812. Alchornea laxiflora (Benth.) Pax & K.Hoffm., AY794957, AY794795. Alchorneopsis floribunda (Benth.) Müll.Arg., AY794962, AY794800. Amyrea sambiranensis Leandri, AY794964, AY794801. Aparisthmium cordatum (A.Juss.) Baill., MG718406, AY794793. Aubletiana macrostachys (Breteler) J.Murillo, AY794960, AY794798. Bocquillonia goniorrhachis Airy Shaw, AY794958, AY794796. Conceveiba guianensis Aubl., JQ626138, AY794791. Conceveiba martiana Baill., AY788170, AY794798. Conceveiba pleiostemona Donn.Sm., JQ591422, AY794794. Conceveiba terminalis (Baill.) Müll.Arg., AY794953, AY794790. Cyttaranthus congolensis J.Léonard, AY794965, AY794803. Discoglypremna caloneura (Pax) Prain, AB267916, AY794802. Mareyopsis longifolia (Pax) Pax & K.Hoffm, AY794961, AY794799. Moultonianthus leembruggianus (Boerl. & Koord.) Steenis, AY794982, MT040392. Necepsia afzelii Prain, DQ991511, DQ991514. Neoscortechinia kingii (Hook.f.) Pax & K.Hoffm., AB267912, AY794806. Paranecepsia andrafiabensis Barberá & O.Lachenaud sp. nov., Madagascar, Diana Region, P. Barberá 2772 (MO), ON505198, ON505201. Paranecepsia andrafiabensis Barberá & O.Lachenaud sp. nov., Madagascar, Diana Region, P. Barberá 2797 (MO), ON505197, ON505200. Paranecepsia andrafiabensis Barberá & O.Lachenaud sp. nov., Madagascar, Diana Region, P. Barberá 2798 (MO), ON505196, ON505199. Syndyophyllum occidentale (Airy Shaw) Welzen, AY794967, AY794805. Pseudagrostistachys ugandensis Pax & K.Hoffm., AY794966, AY794804. Erismanthus leembruggianus Boerl. & Koord., MF435457, HG971870. Paranecepsia alchorneifolia Radcl.-Sm., AB267926, —. Cheilosa montana Blume, MF435455, —. 37