88 BOTANY OF SOCOTRA. 



£ poll, longa. Pedunculi axillares 1-3-conferti pubescentes | poll, longi. Involucellum 

 5-lobatum. Capituhtm globosum. Florcs pilosi. Calycis dentes subciliati rotundati 

 ■^ poll, longi. Corolla \ poll, longa, petalis in parte superiore quarta liberis laciniis 

 deltoideis. Legumen stipitatum 4-5f poll, longum £ poll, latum compressum vix lente 

 curvatum v. fere subfalcatum ad extremitates ambos angustatum subtorulosum, margini- 

 bus planis, valvis lignosis intus septulatis extus convexis obscure lineari-venosis. Semina 

 6-8 globosa fusco-nigra. 



Nom. Vern. Sumach (B.C.S.). 



Socotra. On the plains near the sea on the north side of the island, 

 especially in the vicinity of Delishi. B.C.S. n. 191. Schweinf. n. 260. 



Distrib. Endemic. 



This gummiferous acacia is a very distinct species, referable to the vicinity 

 of A. abyssinica, Hochst. (Benth. Monog. Mimos. 510), and A. nubica, Benth. 

 (loc. cit. 511), the habitats of which are indicated by their names. The last 

 mentioned, however, probably extends into Arabia, about Mascate. Our plant 

 may be readily distinguished from A. abyssinica, by its shorter petioles, long 

 spines equalling the leaves, and by the woody and velvety valves of the pods. 

 From A. nubica its flat-margined pod-valves, as well as the long spines, separate 

 it. Bentham (loc. cit.) notes that Mimosa orfata, Forsk. (Flor. ^Egypt. Arab. 

 177), must be near his A. nubica, but its spines are described as equalling in 

 length the leaves. By this character it would approach more nearly our 

 Socotran plant. 



The bush is very common on the plains in many places. About Delishi, a 

 village east from the Hadibu plain, there are a great number of plants, and there 

 it is that the inhabitants collect the gum in quantity. The gum exudes in tears, 

 and is called " Sumach," the same name as is given to the bush. Although 

 they collect gum, the only use, so far as I could learn, to which they put it is in 

 making ink. It is a simple process. Some soot is mixed with water, and to 

 the mixture a little powdered gum added. A small split stick serves as a pen. 



For further remarks on the gum, see Appendix and Introductory Chapter. 



2. A. pennivenia, Schweinf. in Proc. Roy. Soc. Edin. xiii. (1883). Tab. 

 XXIV. 



Arbor ramis glabris fuscis ; foliis glaberrimis 2-3-pinnatis glandulis nullis ; foliolis laxe 

 7-9-jugis oblongo-obovatis nervo fusco medio dimidiatis venis utrinque 3-4-pinnatis ; 

 floribus albis in capitula racemum laxum formantia v. subpaniculatim dispositis, involucello 

 infra medium basin versus pedunculi griseo-tomentosi subcaduco ; calycis lobis rotundato- 

 ciliatis; corolla calyce dimidio longiore; staminibus exsertis ; legumine ignoto. 



Arbor 30-pedalis glaber. Rami fusci inermes lenticellis verrucosi, juveniles adventi angulosi 

 nigri spinis binis stipularibus fuscis rectis divaricatis £-£ poll, longis basi incrassatis et 

 connatis armati, fertiles congesti trifoliosi. Folia glaberrima 2-3-pinnata rhachi subalata 

 3 poll, longa basi incrassata glandulis nullis ; pinnae 2-3-jugae 2£ poll, longae laxe et 

 alterne v. opposite 15-20-foliolatre; foliola \-^% poll, longa \ poll, lata oblongo-obovata v. 

 eubobcuneata obtusissima v. emarginata basim versus gradatim acutata sessilia v. subsessilia 



