PHANEROGAMS — PROFESSOR BAYLEY BALFOUR. 183 



The Socotran plant is the large-leaved form of the species, the true H. 

 ovalifolium, Forsk. 



8. H. (Orthostachys) strigosum, Willd. Sp. i. 743 ; DC. Prod. ix. 546 ; 

 T. Anders, in Journ. Linn. Soc. v. (1860), Snppl. 25 ; Boiss. Flor. Orient, iv. 

 143 ; Clarke in Hook. Flor. Brit. Ind. iv. 151. 



H. laxiflorum, Roth. Nov. PL Sp. 102 ; DC. Prod. ix. 548. 



H. bracteatum, R. Br. Prod. 493 ; DC. Prod. ix. 547 ; Clarke in Hook. Flor. Brit. Ind. iv. 151. 



H. bicolor, Hochst. et Steud. in herb. Schimp. Arab. n. 848 ; DC. Prod. ix. 546 ; Ach. Rich. 



Tent. Flor. Abyss, ii. 85. 

 H. brevifolium, Wall. Cat. 914; DC. Prod. ix. 546. 

 IT. zeylanicum, Wall. Cat. 2091. 



Socotra. On the plains. B.C.S. n. 531. Schweinf. n. 282 in lit. 



Distrib. Southern Asia, tropical Africa and Australia ; widely spread. 



The specific name above cited is to be regarded as a convenient one under 

 which to group a multiplicity of forms described by various botanists as 

 distinct species, of which a partial list is given. The forms run into one 

 another so completely that specific diagnoses seem to me of doubtful value. 



Our n. 351 may be considered as very near the type, and resembles much 

 the forms growing at Aden and in Arabia generally. Besides it, we have two 

 other forms which I refer to the following varieties. 



var. scabrum. 



H. scabrum, Retz. Obs. ii. 8 ; Clarke in Hook. Flor. Brit. Ind. iv. 152 ; Wight Ic. t. 1389. 



Socotra. On the plains. B.C.S. n. 552. Schweinf. nn. 391 in lit, 790. 



One of the most distinct forms, by its tufted habit and somewhat rosulate 

 leaves. 



var. marifolium. 



H. marifolium, Retz. Obs. ii. 8 ; DC. Prod. ix. 547 (excl. syn.); Clarke in Hook. Flor. Brit. 



Ind. iv. 152 ; Wight Ic. t. 1390. 



Socotra. On the plains. B.C.S. n. 553. 



A very fragmentary specimen, probably of this form, which is characterised 

 by having slightly larger flowers and longer bracts than the preceding. 



9. H. (Orthostachys) nigricans, Balf. fil. in Proc. Eoy. Soc. Edin. xii. 

 (1883), 81. Tab. LIV, B. 



Suffruticosum intricato-ramosum decorticans ramulis strigosis angulosis; foliis suboppositis 

 breviter petiolatis parvis ab forma elliptica ad formam obovatam variantibus nigricantibus 

 strigosis; inflorescentiis paucifloris bracteatis; corollse tubo calyci aequilongo, limbo 

 magno ; stigmate truncato vix bilobato ; nuculis scabridis. 



Suffrutex lignosus intricato- multoque ramosus, cortice glauco albido papyraceo erumpente, 

 ramulis ultimis brevibus 2-4 poll, longis internodiisque sursum dilatatis complanatis 

 strigosis. Folia parva opposita v. subopposita breviter petiolata elliptica v. subrotundata 



