174 BOTANY OF SOCOTRA. 



Order XLVII. GENTIANE^. 



A large family of annual or perennial herbs, rarely shrubby, dispersed over 

 the whole world, but most abundant in mountainous temperate regions. Of 

 the two Socotran genera, one is essentially Indian and east Asian, but reaches 

 in one species tropical Africa, and the Mascarene Islands ; the other has a 

 wide range in the northern hemisphere. 



1. EXACUM. 



Exacum, Linn. Gen. n. 141 ; Benth. et Hook. Gen. PL ii. 803. 



A small genus of some twenty-five species of mostly herbaceous plants with 

 beautiful flowers. The majority are natives of India, but a few extend to 

 China, and the Malay Archipelago. One occurs in tropical Africa and the 

 Mascarene Islands. The three Socotran species are endemic. 



1. E. caeruleum, Balf. fil. in Proc. Roy. Soc. Edin. xii. (1883), 80. Tab. 

 LIU. 



Suffruticosum humile glabrum ; foliis sessilibus v. subsessilibus ovatis trinerviis ; floribus 

 pentameris magnis terminalibus solitariis v. in dichasia pauciflora dispositis ; calycis lobis 

 alatis ; corolla? segmentis cseruleis ellipticis ; antheris lateraliter ad medium debiscentibus. 



Suffrutex vix pedalis lignosus Immilis glaber subprostratus multiramosus, caule tetragono ramis- 

 quebrevibus tortuosis. Folia sessilia v. basalia subsessilia 1-1£ (rarius 2^) poll. longa £-§ 

 (rarius 1) poll, lata ovata late acuta subamplexicaulia basi saepe subcordata crasse coriacea 

 trinervia nitida margine revoluta. Flores magni pentameri ad extremitates ramulorum 

 solitarii v. in dicbasia pauciflora aggregati pedicellati ; pedicelli |— 1 poll, longi erecti. 

 Calycis lobi late ovati acuminati £ poll, longi anguste alati, alis sub fructu auctis. 

 Corollce segmenta elliptica obtusa caerulea £ poll, longa. Anther w £ poll, longae sursum 

 leviter attenuatse et incurvatse lateraliter ad medium debisceutes. Stylus ovario 

 duplolongior apice subcircinatus. Capsula globosa £ poll, longa. 



Socotra. On the higher parts of the Haghier hills, at an elevation of 2500 

 feet. B.C.S. n. 403. Schweinf. n. 672. 



Distrib. Endemic. 



A small woody plant with lovely blue flowers. We only found it on the 

 top of the Sicante Peaks, south from Tamarida, but Schweinfurth has it from 

 above Kischen, so that it probably occurs over the whole Haghier range. 



It is quite distinct as a species belonging to the pentamerous section of 

 the genus. It has resemblance with the Ceylon species E. Walkeri (Arn. in 

 Griseb. Gent. 110, and in DC. Prod. ix. 45), but is quite different from it. 

 The woody suffruticose habit is somewhat exceptional in the genus. 



2. E. affine, Balf. fil. in Proc. Roy. Soc. Edin. xii. (1882), 80 ; Regel Garten- 

 flora xxxii. (1883), 34, t. 1108; Hemsl. in Gard. Chron. xix. (1883), 368. 



Annuum erectum ramosum ; foliis ellipticis v. ovatis acutis longe petiolatis 5-nerviis ; floribus 

 pedicellatis cernuis 5-meris ; calycis lobis late alatis ; corollas lobis obovatis violaceis ; 

 antberis ad apicem debiscentibus. 



