92 



MEMOIRS, OF THE NEW YORK BOTANICAL GARDEN 



[VOL. 10 



COMBRETACEAE" 1 



The three new species of Terminalia described below, together with two 

 recently described species, T. quintalata Maguire of eastern Guayana, in the 

 Kaieteur Savanna, British Gniana Pakaraima, and Gran Sabana Regions, at 

 4-1200 m altitude, and T. yapacana Maguire of low altitude savannas of western 

 Guayana, notably those of Yapacana, Rio Yatua, and Maroa, constitute a group 

 of species which has, apparently, no close affinity with any other known New 

 "World species of the genus. 



These five species all have coriaceous or subcoriaceous leaves, obovate to 

 oblong in shape with short, thick, flattened petioles. This typo of loaf, or at least 

 something similar, is common enough in Malaysian and Polynesian species, but 

 usually associated with drupe-like fruits. Our species, however, have 4—5 winged 

 fruits with membranaceous wings which can be described in general terms as 

 " ' Covribretum-like." The inflorescences are axillary spikes varying from sub- 

 capitate to elongate. 



There is little doubt that we have here a rather isolated group of mutually 

 related species, and a new sectional name must be provided for them. 



In the New World, the nearest affinity in leaf -type seems to be in Ramatuela, 

 an Amazonian genus very closely related to Terminalia and not indeed very 

 convincingly separable from the latter. Although it would be going too far to 

 suggest that sect. Pachyphyllum in any way represents the ancestry of Rama- 

 tuela, it is at least true that the discovery of the five species placed in the new 

 section has reduced the gap between Ramatuela and Terminalia in South 

 America. 



Terminalia sect. Pachyphyllum Maguire & Exell, sect, now 



Flores 4—5-meri in spicas axillares pedunculatas elongatas vel subcapitulatas 

 dispositi. Fructus sessilis 4-5-alatus, alis membranaceis. Ramuli crassi. Folia 

 spiraliter ordinata coriacea plerumque conferta breviter petiolata, petiolo crasso 

 applanato. 



Type species. Terminalia virgata Maguire & Exell. 



Key to the Species of Terminalia sect. Pachyphyllum 



1. Fruits mostly 4-winged; leaves usually obtuse to subcordate at the base. 



2. Branchlets and young leaves densely greyish- villous-tomentose ; spikes subcapitate 



to rfTore or less elongate. 1. T. virgata. 



2. Branchlets either glabrous or soon glabrescent ; spikes subcapitate. 



3. Lower receptacle (ovary) glabrous. 2. T. opacifolia. 



3. Lower receptacle (ovary) densely pilose. 3. T. guaiquinimae. 



1. Fruits mostly 5-winged; leaves cuneate at the base, the lamina merging almost im- 

 perceptibly into the petiole. 

 4. Fruits up to 10 X 9 mm, slightly longer than broad; leaves obovate to obovate- 



elliptic, usually 4—9 cm broad when fully developed. 4. T. quintalata. 



4. Fruits up to 7 X 9 mm, slightly broader than long; leaves elliptic to narrowly 



elliptic, up to 3.5 mm broad. ( 5. T. yapacana. 



1. Terminalia virgata Maguire & Exell, sp. now Figure 10. 



Arbor virgata flexuosa 6-10 m alta, ramulis dense cinereo-villosis crassis 

 4—12 mm diam. Folia spiraliter ordinata ± conferta breviter petiolata, petiolo 



By Bassett Maguire and A. W. Exell. 



