1963] 



BOTAXY OF THE GUAYANA HIGHLANDS PART V 



201 



This geographical hiatus is interesting in that the British Guiana species 

 differs in various respects from all the other species of the genus, while the species 

 from Brazil and southwestern Venezuela are a closely knit group with detailed 

 relationships. The species from British Guiana is the only one of the genus in 

 which all the corolla-lobes show pubescence on their inner surface, whereas in 

 all the other species only one of the corolla-lobes is pubescent within. In the 

 species from British Guiana the calyx-lobes are not cut down all the way, thus 

 leaving a partial tube or hypanthium, whereas in all the other species, the calyx- 

 lobes are deeply cut to the base with overlapping or imbricating margins ; they 

 are also more foliaceous and conspicuous than in H. jenmani. Finally, it should 

 be noted that in H. jenmani the inner surface of the stipules has loose fairly 

 evident ascending hairs, whereas in the other species the pubescence consists of 

 a tomentum of very short and minute puberulence. These differences may be 

 expressed in the following key to the species. 



Key to Species of Henfiquezia 



1. Lower surface of leaves gray-whitish with dense minute papillate excrescences; inner 

 surface of stipules hirtellous with obvious loose ascending hairs; inner surface of 

 all the corolla-lobes villosulous or puberulous ; British Guiana. 1. 77. jenmani. 



1. Lower surface of leaves pale green or green, glabrous but not showing dense papillate 

 excrescences; inner surface of stipules appressed-tomentulose or sericeous, the 

 hairs not obvious: inner surface of only one corolla-lobe villosulous or bearded; 

 southwestern Venezuela, eastern Colombia, and northwestern Brazil. 

 2. Calyx-lobes 25-30 mm long, nearly as long as the corolla-tube. 4. 77. lonr/isepala. 



2. Calyx-lobes 4-18 mm long, 1/4-5/8 as long as the corolla-tube. 



3. Calyx-lobes relatively short, 4-8 mm long, acute or subacute, without over- 

 lapping, imbricate margins, not completely parted to the summit of the 

 ovary, a distance of 3.5-4.5 mm separating top of ovary from base of calyx- 

 lobe; stipules usually absent during or after anthesis; inflorescence usually 

 longer than broad, the 2-4 secondary lateral axes short and ending in the 

 pedicels; lateral nerves sulcate above. 2. 77. verticillata. 



3. Calyx-lobes foliaceous, relatively elongated, 10-18 mm long, generally acu- 

 minate to caudate, some of the lobes with a prolonged apex, some of them 

 with partly overlapping, imbricate margins, the lobes parted all the way down 

 to the summit of the ovary; stipules persistent during and after anthesis; 

 inflorescence usually broader than high or as broad as high, dichotomously 

 cyniose, the 2-3 secondary axes elongating into tertiary axes before ending 

 in the pedicels; lateral nerves impressed or prominulous above. 



3. 77". nitida and varieties. 



1. Henriquezia jenmani Schum. in Mart. Fl. Bras. 6 6 :135. 1889. 



Distribution. British Guiana, along the Mazaruni river and at its junction 

 with the Essequibo River. 



BRITISH GUIANA. Mazaruni River ; tree from 10 to 40 or more feet high ; 

 Sep 1880, G. S. Jenman 629 (holotype K, photo NY) ; Bartico Point, Essequibo 

 and Mazaruni River junction; foreshore on saiiriv silt at or below tide level; 

 13 Sep 1942, Forest Dept. Fiehl No. F 847 (Record No. 3583) (F, NY). 



Reported by N. E. Brown (Trans. Linn. Soc. II 6 : 33. pi. 4. 1901) on collection 

 of Mc Connell & Quelch 711 from Mazaruni River, British Guiana ("This hand- 



K, showing adnation of calyx to summit of ovary with relative distance between lobes and 

 summit of ovary, X 2. L, showing bearding of fifth corolla-lobe and contiguous portion of 

 corolla-tube, X 1. M, showing sericeous zone within of hypanthium and lower part of calyx- 

 lobes, X 2. 



