1963] 



BOTANY OF THE GUAYANA HIGHLANDS PART V 



167 



2. Adulterated, with both simple and gland-tipped cauline hairs. 

 VENEZUELA, Edo. Bolivar. Roraima : Vie 8695 (isotype MG). 

 M. acutifolia. 



1. Atypical, with large leaves and gland-tipped stem hairs, but reddish 

 lower leaf surface pubescence and normal flower size. 



VENEZUELA, Edo. Bolivar. Uaipan-tepui: Phelps & Hitchcock 437 (NY). 



2. Typical, except for gland-tipped stem hairs. 



VENEZUELA, Edo. Bolivar. Chimanta Massif : Car dona 1958, Steyermark 

 75827, Steyermark & Wurdack 1138, Wurdack 34168, 34264. Uaipan-tepui: 

 Phelps & Hitchcock 404. 



3. Typical. 



VENEZUELA, Edo. Bolivar. Roraima: Vie 8694 (isotype MG). Ilu-tepui: 

 Maguire 33403. Sororopan-tepui : Steyermark 60135. Ptari-tepui : Steyermark 

 59587. 



4. Atypical cumbre. with shorter relatively broader leaves. 

 VENEZUELA, Edo. Bolivar. Uei-tepui (Serra do Sol) : Maguire & Maguire 



40414. Chimanta Massif : Steyermark & Wurdack 744. 



Miconia silicicola Gleason. 



Originally described from Roraima and Duida, this widespread species is now 

 known also from the Chimanta Massif, Ilu-tepui, Guanay, Yutaje, and Coro-Coro. 

 The foliage is quite variable in shape, ranging from obovate-elliptic and scarcely 

 contracted to a clasping base to broadly oblanceolate with narrow base. The 

 compiled floral description shows the following : hypanthium 3.8 X 3.5 mm, calyx 

 tube 1.3 mm, the lobes closed in bud and 0.1-0.4 mm high at anthesis each with 

 an external subapical tooth ; petals 4x2 mm, white, obovate with rounded apex, 

 externally cadueously pulverulent; stamens slightly dimorphic in size; filaments 

 5 or 4.5 mm, very sparsely glandular-setulose, the hairs 0.1 mm long; anthers 

 4.1 or 2.8 mm, subulate, the connective base with 1-4 pairs of short-stalked 

 glands ; style 7 X 0.5-0.6 mm, sparsely glandular-setulose on the basal half ; 

 stigma subcapitate, 0.65 mm diam. ; ovary 3-celled, 1/5-inferior, the apical collar 

 0.3 mm high and sparsely glandular-setulose. The slightly smaller flowers and 

 leaves, as well as the stipitate (stalk 0.05-0.1 mm) sublepidote-stellate lower leaf 

 surface pubescence, differentiate M. silicicola from M. plukenetii Naud. ; the latter 

 has sessile sublepidote-stellate foliar hairs. 



Miconia tillettii Wurdack, sp. nov. 



M. pseudocapsxlari Wurdack affinis sed floribus paniculatis non secundis 

 calycis dentibus exterioribus anguste triangularibus vix eminentibus. 



Frutex vel arbor parva 1.5-8 m inflorescentiis exceptis glabra. Folia aequalia 

 vel vix inaequalia ; petioli 1.5-5 cm; lamina 10-30 X 4.5-10 cm elliptica vel vix 

 obovato-elliptica apice per 1-1.5 cm subabrupte hebeti-acuminata basi cuneata 

 membranacea fragilis 5-plinervata jugo interiore subalternatim 1-2.5 cm supra 

 basim inserto jugo exteriore attenuato marginali nervis secundariis plerumque 

 5-10 mm inter se distantibus tertiariis paucis laxissime reticularis integra. 

 Panicula 6-13 cm longa pyramidata inconspicue caduceque furfuracea ramulis 

 ultimis in dichasiis 2-3-floris interdum congestis ; bracteolae 0.3-0.5 mm longae 

 subulatae persistentes ca. 0.8-1 mm infra hypanthium insertae ; flores 5-meri ca. 

 1-1.2 mm pedicellati glabri. Hypanthium (ad torum) 2.5 X 1.5 mm anguste 

 oblongum vix 10-costatum ; calycis tubus 0.1 mm altus, lobis interioribus 0.5-0.6 



