PHANEROGAMS— PROFESSOR BAYLEY BALFOUR. 73 



8. INDIGOFEEA. 

 Indigo/era, Linn. Gen. n. 889 ; Benth. et Hook. Gen. PI. i. 494. 



A very large genus of the warmer parts of the globe, attaining a maximum 

 in tropical and south Africa. Ten species are found in Socotra. Of these, two 

 are endemic; three are Arabian and south-west Asiatic species, one of them 

 also reaching Nile Land ; three are tropical African and southern Asiatic forms, 

 two of which also extend to Australia ; one is north Indian only, and the tenth 

 is a widely cultivated species. 



1. I. nephrocarpa, Balf. fil. in Proc. Roy. Soc. Edin. xi. (1882), 509. 

 Tab. XVIII, A. 



Depressa canescens ; foliis alterne trifoliolatis petiolatis strigosis ; stipulis inconspicuis ; 

 racemis paucifloris subsessilibus v. filiformiter pedunculitis ; legumine minuto 1-spermo 

 reniformi ; stylo persistente. 



Perennis depressa lignosa a basi rarnosissima congesta v. diffusa. Rami bumifusi saepe late 

 patentes fere pedales scabriduli. Folia alterne trifoliolata in forniis congestis |— £ poll, 

 longa brevissime petiolata dense pilis albis adpressis vestita, in diffusis | poll, longa 

 petiolo filiformi £ poll, longo sparsimque strigosa sed inter extremas multos gradus exhi- 

 bentia ; foliola obovata v. ssepe oblonga nee quam \ poll, longa majora subcrassa. Stipitla; 

 rninutse inconspicuse. Mores parvi 3-6 ad extremitatem rbacheos filiformis \-^ poll, longae 

 (in plantis congestis fere absentis) axillaris capitato-racemosee conferti ; pedicelli ^ poll, 

 longi ; bracteolae minutissimie setiformes. Calyx ^ poll, longus extus pilosus, lobis subu- 

 latis subaequalibus tubo inultolongioribus. Corolla purpurea ; vexillum orbiculare vix 

 unguiculatum ^ poll, longum extus pubescens ; alae angustae truueatse carina vexilloque 

 parum breviores. Stylus ovario quadruplolongior multoincurvatus. Zegumen fy poll, 

 diarn. reniforme curvatum strigosurn stylo persistente longo terminatuni 1-spermum. 



Socotra. A common plant of the plains. B.C.S. nn. 85, 104, 336 ? 

 Schweinf. n. 237. 



Distrib. Endemic. 



Amongst the one-seeded species of Indigofera this is easily recognised by 

 its fruit, which is so much bent upon itself as to become quite kidney- shaped f 

 and the long persistent style coils round it. 



As is so common in Socotran plants, its appearance when growing on the 

 harder portion of the limestone plains differs from its aspect when in more 

 congenial localities. In the first-mentioned circumstances it forms a hard, tufted 

 depressed plant (n. 85), with branches, at times almost spiny, always greatly 

 shortened, and hence the leaves, and the flowers, and fruit, which latter are in 

 almost sessile clusters, become aggregated into a compact form. When under 

 more favourable conditions, it gives off spreading branches with elongated 

 internodes, and the leaves are longly and delicately petioled, whilst the flowers 

 and fruits are in capitate racemes on slender rhachi (n. 104). 



We have a specimen (n. 336) from the island which I think is to be referred 

 to this species, but the leaflets have become long linear lanceolate, often a half- 



TRANS. ROY. SOC. EDIN. VOL. XXXI. K 



