The Groivth- Forms of Natal Plants. 
681 
STEM SUCCULENTS. 
These belong to a very few genera in the family Asclepiadaceae, viz. : 
Caralluma lutea (stems 1^-4 in.), Stajjelia gicja7itea, and Stajjelia woodii, 
Huernia hystrix, Sarcostemma viminale, Cynanchtmi sarcostemmatoides, and 
about 28 species of JEupJiorhia. 
The total number of Stem Succulents is therefore cir. 80. 
The genus Etiphorhia is very well represented in Natal and is one of the 
most heterogeneous in its growth-forms. It includes common field weeds 
and large trees, e.g. E. tirucalU and E. grandidens. The tree Euphorbias 
are very abundant in the dry river valleys and rocky hillsides of the Low 
Yeld region. The Euphorbiaceae have not yet been dealt with in the Flora 
Capensis. 
All stem succulents, like the other members of the families to which they 
belong, have a milky latex. This distinguishes the African forms from the 
similar " Cactoid " forms of America. The latex in both Euphorl)ias and 
Asclepiads is contained in the coenocytic type of laticiferous element. The 
readiness with which it flows shows that in most cases it is under high 
pressure in the plant. 
EPIPHYTES. 
If we restrict ourselves to the seed -bearing plants, the Epiphytes of 
Natal are about equal in number to the Stem Succulents. A large number 
of Pteridophyta and Bryophyta might, however, be added. 
The total number of Epiphytes is cir. 84, the bulk of them being Orchids. 
They are not particularly abundant individually. The species Bhipsalis 
cassytha, our only representative of the family Cactaceae, is a fleshy, cord- 
like plant hanging from trees, but often found also on rocks. Hence it 
might have been included among Stem Succulents. 
Bermatohotrys saundersii (Scroph.), a recently discovered species of 
Cyrtanthus (C einiJhyticus J. M. Wood), and two species of Peperomia, with, 
cir. 80 species of Orchids belonging to the genera Polystacliya, Angraecum, 
and Mystacidiiim, complete the list. Fic2is natalensis begins its life as an 
epiphyte. 
HETEEOPHYTES. 
These, though a small group, formed one of Warming's six main 
classes, and rightly so, for they differ from all other growth-forms among 
flowering plants. 
In Natal we have the following : Cuscuta (4 species) and Cassytho 
capensis (holo-parasitic stem parasites), Lorantlms (5 species), Visciim 
(8 species) (hemi-parasitic stem parasites). 
