lxvi 



BOTANY OF SOCOTRA. 



Some of the species included in the foregoing list have quite an exceptional 

 eastern extension in Socotra, and cannot justly be considered as plants of the 

 north-east corner of Africa and of south-west Asia. For instance, Campanula 

 dichotoma and Convolvulus siculus are not known further east than Syria upon 

 the mainland. Again some forms, whilst of Asiatic distribution, do not reach 

 the African coast. This is the case with Silene apetala and Cuscuta planiflora, 

 var. globidosa, which have a wide range on the north of the Red Sea, the latter 

 reaching into Asia Minor, the former spreading as far as the Canary Islands. 



Thirty-five Socotran species — of which seven are annuals — are found in 

 Africa, but do not reach Asia, and the distribution of some of these is remark- 

 able, bearing out the strong Abyssinian, south African and east and west tropical 

 African highland relationships of the flora. As an example of extreme sporadic 

 distribution, Sarcostemma Daltoni may be quoted, for it is known from the Cape 

 de Verde Islands, and now turns up in Socotra. The relationships of these 

 African species will be best understood from the following table : — 



List of thirty-five species of the phanerogamic flora of Socotra which 



are African but not Asian. 



Species. 



Diceratella incana, 

 Manna angolensis, . 

 Cadaba rotundifolia, 

 Aberia abyssinica, 

 Hypericum lanceolatum 

 Hibiscus ternatus, 

 Sterculia Triphaea, 

 Rhus glaueescens, 

 Crotalaria spinosa, 

 Tephrosia subtrittora, 

 ,, anthylloides, 

 ,, vicioides, 

 Kalanchoe rotundifolia, 

 Diricbletia glaucescens, 

 Conyza Hoehstetteri, 

 Achyrocline Luzuloides, 

 ,, Schimperi, 



Tripteris Lordii, 



Wahlenborgia riparia, 



Euclea Kellau, 

 Carissa Schimperi, 

 Adenium multillorum, 



Glossonema Revoili, 



Sarcostemma Daltoni, 

 Dremia angolensis, 

 Ecliidnopsis cereiformia, 

 Linaria bastata, 

 < >robanche abyasiDica, 

 Leucas Nenflizeana, 

 Buxus Ilildebiaudti, 

 Atwtralina capensia, 

 A iparagos africanus, 



E mil i isi\ he bispidula. 

 I'anicum nudiglume, 



Panicum atrosanguin- nn, 



Distribution and Remarks. 



Somali-land. Genus tritypic, other species natives of Persia. 



Tropical Africa. 



Nile-land. 



Abyssinia. 



Highlands of Africa, Madagascar, Mascarene Islands. 



Tropical Africa. Annual. 



From Abyssinia to Mozambique. 



Tropical and south Afiica. 



Tropical Africa. Annual. 



Abyssinia. 



Tropical Africa. 



Nubia and Abyssinia. 



South Africa. 



Somali-land. Distribution of genus is referred to on page lxi. 



Abyssinia and Kilima Njaro. 



Somali-land, Nile-land, Upper Guinea. 



Nile-land, Mozambique. Annual. 



Upper Nubia. Essentially a south African genus ; only two 

 species are north African. Represented by an endemic variety 

 on Soi-otra. Annual. 



Upper Guinea. Annual. 



Abyssinia. Distribution of genus is referred to on page lxi. 



Abyssinia. 



Mozambique. Belongs to a genus of five species only, one of 

 which occurs in Arabia, Nubia, and east tropical Afiica ; one 

 grows in Senegambia and west tropical Africa; one at Aden, 

 and one in Somali-land ; the fifth is the Socotran and Mozam- 

 bique plant. 



Somali-land. Genus of six or seven species natives of Arabia 

 and tropical Afiica ; one is south African. 



De Verde Islands. 



Tropical Africa. 



Abyssinia. Monotypic genus. 



Abyssinia. Annual. 



Abyssinia. 



Abyssinia, Dessi Island, east tropical Africa. 



Somali-land. 



South Africa. Genus is Australian and south African. 



Tropical and south Africa. Represented by an endemic variety 

 on Socotra. 



Tropical Africa. 



Abyssinia, Egypt. Annual. The Abyssinian variety major 

 also occurs on Socotra. 



Abyssinia, 



