MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



| VOL. 10 



able resemblance in aspect, M. iluensis is more closely related to species 18-27 

 of Cogniaux' monograph; all of these species have either glandular filaments, 

 smaller flowers, or smaller bracts. 



Miconia superba Ule. 



A£. pachypoda Gleason, Fieldiana Bot. 28: 435. 1952. 



Certainly two morphologically distinct species arc involved in the M. pachy- 

 poda-M. superbar-M. acutifolia Ule complex, the ends of the line being alti- 

 tudinally separated (as quite clearly seen by me on the Chimanta Massif). In 

 the ecotone, however, there apparently has been hybridization, and unfortunately 

 Ule 8695 represents an intermediate. In overall features (flower and leaf size), 

 the Ule collection falls slightly nearer M. pachypoda. The intermediates here 

 placed under M. acutifolia show varying development of gland-tipped hairs up 

 to 1.5 mm long on the stems, petioles, and inflorescence, but have the leaf and 

 flower size of the eglandular Ule 8694. In the cumbres, M. acutifolia shows a leaf 

 size reduction over the subcumbre elements and, like typical M. acutifolia, lacks 

 glandular hairs. 



In addition to the above complications, I believe there has been some hybridi- 

 zation between M. acutifolia and the widespread species M. guianensis (Aubl.) 

 Cogn. and N. dodecandra (Desr.) Cogn, both of which are found in the eastern 

 tepui slope forests. Maguire 33416, from Ilu-tepm, apparently is M. acutifolia 

 with strong introgression (broad leaves, rather smaller stellate hairs) from 

 M. guianensis. Cardona 211 ( Auyan-tepui) , Steyermark &' Wurdack 1003 

 (Chimanta Massif), and Steyermark 59718 (Ptari-tepui) have rather narrow 

 rigid leaves suggestive of M. acutifolia, but with the strongly stellate-pubescent 

 hypanthia of M. dodecandra. The species nodes in these four taxa (all char- 

 acterized by stellulate-pubescent tori) may be keyed as follows: 



1. Hypanthia densely stellulate-pubescent. M. dodecandra. 



1. Hypanthia glabrous at anthesis. 



2. Stems densely setose with simple hairs 5-12 mm long. M. superba. 



2. Stems with or without gland-tipped smooth hairs, but without simple hairs. 



3. Leaf blades thin-coriaceous, the lower surface pubescence pale brown. M. guianensis. 

 3. Leaf blades rigid-coriaceous, the lower surface pubescence tawny. M. acutifolia. 



The key characters for separation of M. superba and M. acutifolia, including 

 most hybrid elements, are : 



Stem seta* (in part at least) simple, without glandular-tips, 3-12 mm long; leaf blades 

 10-25 cm wide, the lower surface pubescence pale brown; hypanthium plus calyx 

 6.5-7 mm long. M. superba. 



Stem setulae absent or gland-tipped, to 1.5 mm long; leaf blades at most 7 cm wide, the 



lower surface pubescence rufous; hypanthium plus calyx 4.5-5 mm long. M. acutifolia. 



The variability between M. superba and M. acutifolia may be arranged lineally 

 as follows : 



M. superba. 



1. Unadulterated, as in M. pachypoda, with only simple long cauline 

 pubescence. 



VENEZUELA, Edo. Bolivar. Chimanta Massif : Steyermark 75152, Wurdack 

 34077. Serrania Paujil : Bernardi 6824. Aprada-tepm : Bernardi 776. Ptari-tepui : 

 Steyermark 59447. Uu-tepui: Maguire 33612. Cerro La Danta: Steyermark & 

 Nilsson 223. BRITISH GUIANA. Karowtipu: Tillett & Tillett 45556. 



