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Summary: A review of Crassula zombensis (Cras-
sulaceae), a hardly known species documented
only by few collections from Zomba Plateau
(Malawi) and the Serra de Gúruè (Mozambique),
is provided, describing its history, specimens, lo-
calities and habitats. On Zomba Plateau, C.
zombensis may grow as an epiphyte on Xerophyta
kirkii (Velloziaceae); further species (succulents,
orchids, herbs) known to occur epiphytically on
Xerophyta spp. in Malawi are listed. The IUCN
Red List Conservation Status is assessed as Near
Threatened (NT).
Zusammenfassung: Eine Übersicht über Crassula
zombensis (Crassulaceae), eine kaum bekannte
Art, die nur durch wenige Aufsammlungen vom
Zomba-Plateau (Malawi) und der Serra de Gúruè
(Mosambik) dokumentiert ist, beschreibt die Ge-
schichte, Herbarexemplare, Fundorte und den Le-
bensraum der Art. Auf dem Zomba-Plateau
kommt C. zombensis auch epiphytisch auf Xero-
phyta kirkii (Velloziaceae) vor; weitere Arten
(Sukkulenten, Orchideen, nicht-sukkulente krau-
tige Pflanzen), die in Malawi epiphytisch auf Xe-
rophyta spp. vorkommen, werden aufgelistet. Der
IUCN Rote Liste Gefährdungsgrad wird als
potenziell gefährdet (NT) bewertet.
Keywords: Crassula zombensis, Crassulaceae,
Flora of Malawi, Flora of Mozambique, Zomba
Plateau, Serra de Gúruè (Namuli Mt.).
Introduction
The Crassulaceae of tropical south-east Africa
comprise the genera Crassula, Kalanchoe (incl.
Bryophyllum), and Cotyledon and received a com-
plete treatment by Fernandes (1983) for the
“Flora Zambesiaca” (FZ), covering Botswana,
Malawi, Mozambique, Zambia, Zimbabwe and the
Caprivi Strip of Namibia. With some 24 species,
Crassula is by far the largest genus in the area.
Since Fernandes’ treatment, additional contribu-
tions were published on the taxonomy and nomen-
clature (e.g., Wickens, 1982; Rowley, 2003; van
Jaarsveld, 2003) and the chorology (eg., Harris et
al., 2011; Thiede et al., 2017) of Crassula in the
FZ area.
Many Crassula species in the FZ area are
widespread (Fernandes, 1983), ranging from
southern to SE Africa (e.g., C. setulosa Harv.), to
SE Africa and Madagascar (e.g., C. fragilis
Baker), to Eastern and Central Africa (e.g., C.
alsinoides (Hook. f.) Engl.), or up to NE Africa
(e.g., C. vaginata Eckl. & Zeyh.) or even Asia (e.g.,
C. schimperi Fisch. & Mey.), and are dealt with in
several flora works and taxonomic papers. In con-
trast, species of local or restricted distribution
such as C. maputensis R. Fernandes, C. morrum-
balensis R. Fernandes and C. zombensis Baker f.
(Fernandes 1983) remained poorly known. Cras-
sula zombensis, a species only known from two
mountain areas in Malawi and Mozambique, be-
longs to the least known Crassula species in the
FZ area and is dealt with in detail here.
Methods
The second (TPCB) and third author (BJH)
both lived for many years in Malawi and carried
out field studies on the Zomba Plateau. The first
author (JT) studied a specimen in the National
Herbarium of Malawi (MAL) on 09.04.1991, and
further specimens from digital images. Specimen
and observation data were provided by the Royal
Botanic Gardens, Kew (K) via the Global Biodi-
versity Information Facility (www.gbif.org) or
other resources, 2017-05-01 or later. The extent of
occurrence (EOO) and the area of occupancy
(AOO) were calculated with the online conserva-
tion assessment tool GeoCAT (2017).
212 Bradleya 35/2017
Bradleya 35/2017
pages 212–216
Crassula zombensis (Crassulaceae) - a hardly known species
from Malawi (Zomba Plateau) and Mozambique (Serra de
Gúruè/Namuli Mt.)
Joachim Thiede1, Pastor Theo Peter Campbell-Barker2, & Bruce J. Hargreaves3
1. Schenefelder Holt 3, 22589 Hamburg, Germany (email: joachim_thiede@gmx.de).
2. Faringdon Avenue, Lutterworth LE17 4DJ, England (email: theo.cb@talktalk.net).
3. Pryor Street, Bakersfield, CA 93308, USA (email: brucejhargreaves@hotmail.com).
Results and discussion
Type collection and publication. The first and
type collection of C. zombensis consisting of seven
short, leaf-bearing stems (Whyte s.n., K) was
made in December 1896 by Sir Alexander Whyte
(1834–1908), government botanist under the Bri-
tish administration in the then Nyasaland (now
Malawi). He collected the plant without exact lo-
cality on Zomba Mountain (Zomba Plateau), a
massif in southern Malawi up to 2087m high for-
ming part of the Shire Highlands (Figure 1).
Whyte sent significant plant collections from Nya-
saland to Kew and the British Museum, among ot-
hers also the type specimens of Crassula nyikensis
Baker f. (now included in C. globularioides Britten
(APD 2016) and of Monadenium parviflorum
N.E.Br. (now Euphorbia neoparviflora (N.E.Br.)
Bruyns). Kew botanist Edmund Gilbert Baker
(1864–1949) soon thereafter published C. zomben-
sis as a low perennial herb with leaf-bearing
stems branched from the base with opposite
white-hairy, narrowly lanceolate leaves 12.5–19
mm (6–9 lines) long (Baker 1897: 266).
Additional specimens. Further collections of C.
zombensis on Zomba Plateau were not made until
more than 70 years later: in 1967 by Malawian
botanist A. J. Salubeni near Ngondolo Compound
(Salubeni # 812; K, MAL), and in 1970 by Kew
botanist R. K. Brummitt and Malawian botanist
E. A. Banda opposite Malosa saddle (Brummitt &
Banda # 12377; K). A. Moriarty’s specimen # 347
(K) collected at Ngondola in 1970 was misidenti-
fied as C. globularioides and served as voucher for
plate 36 (Fig. 3) in her book (Moriarty, 1975) la-
belled with that wrong name. The rather narrow
leaves and long, slender stems with distinct in-
ternodes, and the description as “flowering stems
which grow from creeping branches” (Moriarty,
1975: 72) clearly place Moriarty # 347 here.
In July 1962, the succulent researcher L. C.
Leach and South African botanist E. A. C. Schelpe
collected a Crassula (Leach & Schelpe # 11483, K)
on “Namuli Peaks”, granitic peaks in the Serra do
Gúruè in NE Mozambique (Figure 1). The speci-
men was identified as C. zombensis by the Ger-
man botanist and Crassula student H. Ch.
Friedrich in 1971, but this first record from
Mozambique and outside Zomba Mountain was
not published until Fernandes (1978). Fernandes
(1978) cited two further specimens preserved from
cultivated material originally collected 1966 and
1967 in the Serra do Gúruè at Namuli Peak and
near the Rio Licungo cascade, respectively (Torre
& Correia # 14734, LISC; Torre & Correia #
16030, LISC).
Further studies. Binns (1968: 41) and Harg-
reaves (1978: 35) briefly mentioned C. zombensis
from Zomba Plateau. Moriarty’s (1975) plate 36
(Fig. 3), labelled C. globularioides, is vouchered
213
Bradleya 35/2017
Figure 1. Distribution of Crassula zombensis (or-
ange dots) in Malawi (Zomba Mt.) and Mozam-
bique (Serra do Gúruè); dots may represent more
than one record
Map: Wikimedia Commons 2015.
Figure 2. Crassula zombensis flowering in culti-
vation, originally collected near Chingwe’s Hole
on Mt. Zomba, Malawi (29 Aug. 1978).
Photograph: Bruce J. Hargreaves
by Moriarty # 347 which is actually C. zombensis,
but the leaves on the plate are much too broad for
the latter. The description (Moriarty, 1975 : 72)
mixes features of both species: The “flowering
stems which grow from creeping branches” fit
with C. zombensis, whereas the leaves “ovate-
lanceolate” forming “rosettes” and the localities
“Zomba and Mulanje” fit with C. globularioides;
C. zombensis is absent from Mt. Mulanje. Fer-
nandes (1978: 196–197, tab. xiv & xv) down-
ranked C. zombensis to a variety of C. swaziensis
Schönl. (= C. swaziensis [subsp. swaziensis] var.
zombensis (Baker f.) R. Fernandes), a species
from Southern and SE Africa with likewise hairy,
but larger and broader leaves often in ± dense
rosettes (Thiede et al., 2017) – a decision hardly
followed by subsequent authors. Fernandes also
corrected the growth form of C. zombensis, de-
scribing it as forming ± dense mats of prostrate,
thin, branched main stems with erect to ascend-
ing, leafy stem-tips (cf. Figure 3). This growth
form became apparent from additional specimens
available to Fernandes (Brummitt & Banda
12377; Leach & Schelpe 11483), but not from the
type consisting of stem-tips only. In addition, Fer-
nandes reproduced two specimens (Leach &
Schelpe # 11483, SRGH; Torre & Correia # 14734,
LISC) - the sole photographs of C. zombensis pub-
lished as yet. Hargreaves (1979: 29–30) published
a third locality from Zomba Plateau “on rocks on
the other side of the forest from ‘Chingwe’s Hole’“
and a sketch of the plant. A plant from this local-
ity was cultivated by him and brought into flower
(Figure 2). Campbell-Barker also observed C.
zombensis near ‘Chingwe’s Hole’ where it is not
common, eventually growing epiphytically on Xe-
rophyta shrubs (Figure 3), observed it at Ngon-
dolo where it was found more common, and
discovered a further, as yet unpublished, small
population about 30ft. (ca. 9m) wide, growing at
an altitude of about 1600m exclusively on Xero-
phyta, about 700ft. (ca. 213m) above the small vil-
lage of Kumbawa (in the central depression of the
Zomba massif half-way between the Zomba and
Malosa saddles). Fernandes (1983), in his Flora
Zambesiaca treatment, recognized C. zombensis
again on species level and provided a detailed de-
scription. Hargreaves (1991: 81) briefly men-
tioned C. zombensis, Porembski (1996: 5) listed it
as an inhabitant of inselbergs in Malawi and
Mozambique, and van Jaarsveld (2003: 84) pro-
vided a short account.
214 Bradleya 35/2017
Figure 3. The first published habitat photograph of Crassula zombensis in bloom on Mt. Zomba, grow-
ing as epiphyte on the xerophytic shrub Xerophyta kirkii (with long and narrow green leaves and large
white flowers on lower right). Photograph: Pastor Theo Peter Campbell-Barker.
Distribution and habitats. Crassula zombensis
is known from four localities on Zomba Plateau in
Malawi (at Ngondolo Compound, opposite Malosa
saddle, near Chingwe’s Hole, and above Kum-
bawa) and from two localities in the Serra do
Gúruè in Mozambique (Namuli Peaks and near
the Rio Licungo cascade), growing on rock
outcrops and slopes at 1600–1900m (Zomba mas-
sif) and 1200–1370m (Serra de Gúruè).
Conservation status. Based on the specimens
and sight records cited here, the conservation sta-
tus of C. zombensis is assessed with the IUCN Red
List system (IUCN, 2001). The extent of occur-
rence (EOO) is 449km2which is far below the
threshold of 5000km2for Endangered (EN). The
corresponding area of occupancy (AOO) is 24km2
based on a cell width of 2km which is also below
the threshold for EN (<500km2). Neither Zomba
Plateau nor the Serra do Gúruè is formally pro-
tected. Immediate threats present on Zomba
Plateau (invaders, grazing, grass fires, deforesta-
tion, spread of pine plantations) are not known to
threaten the C. zombensis rock habitats. In
Malawi, Xerophyta stems with adhering epiphytes
are collected and sold as brushes, pot cleaners and
natural torches (Morris, 1996: 490; Campbell-
Barker, obs.), but it is unknown whether C.
zombensis is affected. The status of the habitats
in the Serra do Gúruè is unknown.
The extent of occurrence (EOO) and the area of
occupancy (AOO) would qualify for EN, but no ad-
ditional criteria for EN or for Vulnerable (VU)
such as reduction in population size or population
decline are met with or are unknown, so that C.
zombensis is classified as Near Threatened (NT).
Epiphytic occurrence on Xerophyta.The pho-
tograph by Campbell-Barker (Figure 3) showing
C. zombensis as epiphytic on a Xerophyta shrub
represents the first record of the species occurring
as an epiphyte. The persistent bilobed scale-like
leaf sheaths arranged like roof tiles (cf. Figure 3)
permit the identification of the phorophyte as X.
kirkii (Hemsl.) L.B.Sm. & Ayensu, the sole
shrubby Xerophyta species on Mt. Zomba (cf.
Behnke et al., 2013). The sole epiphyte on Xero-
phyta previously known from Zomba Plateau is
the orchid Polystachya johnstonii Rolfe (Morris,
1970: 65; Moriarty, 1975: 56; Hargreaves, 1979:
33; la Croix et al., 1983: 92; la Croix et al., 1991:
229; Cribb & la Croix, 1997).
The occurrence of epiphytes on Xerophyta
shrubs is not uncommon in Malawi (and else-
where in tropical Africa): On a rock outcrop at
Sombani Plateau on Mt. Mulanje (S Malawi),
about 70 % of the Xerophyta shrubs supported epi-
phytic orchids of six different species and with ten
orchid plants per shrub on average (Morris, 1970:
13–14). Further epiphytes on Xerophyta spp. in
Malawi include Crassula setulosa Harv. (both
Zomba massif & Mt. Mulanje, Campbell-Barker
obs.), C. globularioides Britten (Morris, 1970: 13,
Mt. Mulanje; Campbell-Barker obs., Mt. Mulanje:
Sombani Plateau), Cynanchum viminale (L.)
Bassi (most probably ssp. mulanjense (Liede &
Meve) Goyder; formerly Sarcostemma viminale
(L.) R.Br., Apocynaceae; Campbell-Barker obs.,
Mt. Mulanje); Plectranthus spp. (Lamiaceae; la
Croix et al., 1991: 8; Campbell-Barker obs., Mt.
Mulanje), Helichrysum densiflorum Oliv.
(Strugnell, 2006: 54, Mt. Mulanje), H. whyteanum
Britten (Morris, 1970: 13, Mt. Mulanje), and about
a dozen species of orchids especially in the genus
Polystachya (Morris, 1970; la Croix et al., 1983; la
Croix et al., 1991). Polystachya johnstonii from the
Shire Highlands and Mt. Mulanje has been found
exclusively on Xerophyta shrubs (Morris, 1970:
63–65; Moriarty, 1975: 56; la Croix et al., 1983:
92; la Croix et al., 1991: 7–8, 229; Cribb & la Croix
1997) and is one of few examples for host-specifity
among epiphytic orchids (Porembski, 2003).
Crassula zombensis Baker f., Diagnoses
africanae, X. Bull. Misc. Inform. 11(128–129):
266. (Aug–Sep) 1897.
= Crassula swaziensis var. zombensis (Baker f.)
R. Fernandes in Bol. Soc. Brot., Sér. 2, 52: 196, t.
14 & 17. 1978.
MALAWI, [Southern Region, Zomba Distr.,] Mt.
Zomba found on rocks, 4000–6000 ft., xii.1896, A.
Whyte s.n. (K barcode K000310459! holo).
MALAWI, [Southern Region,] Zomba Distr.,
Zomba Mt., near Ngondolo Compound. Herb 3–
6in (7.6–15.2cm) high. Flowers white, leaves
thick, fleshy. 15.viii.1967, A.J. Salubeni 812 (K
barcode K000285845!; MAL!; SRGH).
MALAWI, Southern Region, Zomba Distr., Zomba
Plateau, below road to summit opposite Malosa
saddle, U.T.M. grid ref. 745: 8304; rocky slopes.
Stems, leaves and sepals dark red; petals white;
anthers yellow. 1900m, 2.viii.1970, R.K. Brummitt
& E.A. Banda 12377 (K barcode K000285844!).
MALAWI, [Southern Region,] Zomba Distr.,
[Zomba Mt.,] Plateau at Ngondola. Sunbaked
rocks, and also seepage rock, often with Xero-
phyta. Leaves become very colourful - pink grey
ochre-green. Flowers white with red centres.
4.viii.1970, A. Moriarty 347 (K barcode
K000318217!; as C. globularioides).
MOZAMBIQUE, Zambesia Prov., Namuli Peaks,
W. face, ca. 4500ft. [1371m]. On rock outcrops.
Plants mat forming, apical portions of stems as-
cending. Flowers white, leaves purplish in dry si-
tuations. 26.vii.1962, L.C. Leach & E.A.C.L.E.
Schelpe 11483 (K barcode K000285847!; LISC;
SRGH).
ex cult. Sintra (Portugal), leg. iv. 1968, coll. MO-
215
Bradleya 35/2017
ZAMBIQUE, Zambesia Prov., in summis jugis
Gúruè, pr. cataractam, ad viam versus “Pico Na-
muli“, ad rupes, ca. 1200m, 21.ii.1966, Torre &
Correia 14734 (LISC) (cited from Fernandes 1978:
196–197 & tab. xv).
ex cult. Sintra (Portugal), leg. iv. 1968, coll. MO-
ZAMBIQUE, Zambesia Prov., encosta da serra do
Gúruè, picada pela cascata do rio Licungo, em di-
recção ao régulo Mgunha, ao km 18 da fábrica
Moçambique; erva suculenta sobre rocha, inflo-
rescência do ano anterior, floresta ribeirinha com
Parinari, Syzygium, Anthochleista, etc.; ca.
1300m, 9.xi.1967, A.R. Torre & Correia 16030
(LISC) (cited from Fernandes 1978: 197).
Acknowledgements
The authors are indebted to Graham Charles
(UK) for his editorial work. The first author (JT)
acknowledges the staff of the National Herbarium
of Malawi (MAL) for granting access to its collec-
tions in April 1991, and a travel assistance grant
received from the Emmy and Alfred B. Steffens
Memorial Fund of the University of Hamburg in
1991.
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