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149
THE GENEEA OF STAPELIE^.
The most recent number (March, 1890) of the ' Icones Plantaruni'
is devoted enth-ely to ilhistrations and descriptions of the
StajieliecB collected by Sir Henry Barkly in South Africa, from the
pen (and in some instances from the pencil) of Mr. N. E. Brown.
Mr. Brown has for twenty years worked assiduously at this
interesting and difficult group of plants, and the present may be
regarded as a contribution to the monograph which we hope for
from his pen. Besides the descriptions and figures, Mr. Brown
gives us a key to the genera, prefaced by an interesting sketch of
the growth of our knowledge of the group, and valuable remarks
based upon his studies of the plants in cultivation as well as in a
dried state. These tend to show that the reduction of genera here
made by Mr. Brown will be carried further as our knowledge of the
group increases. " In spite of having thus limited the genera to
few, rather than increased their numbers," he says, "I am of
opinion that some of the genera still retained are more artificial
than natural ; for instance, Frerea and Triclwcaulon only differ
from raralluma in habit, and Trichocaulon only differs from Hood in
in its corolla, for although some of the species have a different
corona, one has a corona undistinguishable from that of Hoodia;
possibly it would be more logical and convenient, after all, to do as
our predecessors did, and place them all in the genus Stapelia, with
the exception of JJecabelone, Diplocijatha, Duvalia, Huernut, and
Huerniopsis." Thirteen genera, however, are still retained, and
are arranged by Mr. Brown as follows :
I. Corona simple, outer corona wanting (very rudimentary in
Echidnnpnis. See also Caralluma hottentotonim).
1. Stems usually 4-angled, occasionally 5- to 6-angled, short.
Corolla distinctly campanulate ; coronal segments stout, with
the apex produced, erect. 8. Huerniopsis N. E. Br.
Corolla rotate, or rarely with a very short tube, not campanulate
; coronal segments crested on the back. 12. Pia-
RANTHUS E. Br.
2. Stems teretcly many-angled, tcssellate-tuberculate, elongating.
Corolla small, saucer-shaped ; coronal segments not crested.
8. EcHiDNOPsis Hook. f.
II. Corona double, outer corona present, arising from the staminal
tube.
1. Lobes ofthe corolla cohering at their apex. 4. PECTiNARiAlIaw.
2. Lobes of the corolla not cohering at their apex.
A. Limb of the corolla nearly entire, 5-cuspidate, the lobes
almost obsolete, outer cnrona cup-shaped, 5-lobed ; stems
with numerous tuberculate angles, the tubercles bristletipped.
6. HoowA Sweet.