!()() 



MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



[vol. 10 



of Macrocentrum are much more extensively distributed than previously indi- 

 cated. The best-collected of the widespread species is M. glandulosum Gleason, 

 known from the western Venezuelan sandstone area eastward to Cerros Venamo 

 and Uei (Steyermark & Nilsson 317, 445) in extreme southeastern Estado Bolivar 

 (and certainly to be expected on the Kaieteur Plateau in British Guiana). 



Boyania Wurdack, gen. nov. 



Tribus Bertolonieae sensu Cogniaux. Flores 5-meri. Stamina isomorphica ; 

 connectivum basi antice 1-appendiculatum postiee appendice plerumque caudi- 

 formi descendenti instructum ; ovarium superum 5-loculare, Genus monotypicum. 



Boyania ayangannae Wurdack, sp. nov. Fig. 67, a-f . 



Herba suffruticosa simplicicaulis vel vix ramosa 15-50 em alta ; caulis primum 

 dense glandulis sessilibus vel vix stipitatis rubris obsitus tarde glabratus. Petioli 

 1-1.5 cm longi lateraliter dense setulosi pilis laxis 0.5-1 mm longis, nodis inter- 

 petiolaribus membrana elliptica ca. 2 mm alta stipuliformi caduca instructis; 

 lamina 5-12 X 3-6 cm late ovato-elliptica apice late acuta basi obtusa vel 

 rotundata membranacea, supra sparsissime vel modice strigulosa pilis laxis 0.5-1 

 mm longis, subtus in superficie sparse et in venis modice cum glandulis sessilibus 

 clavatis obsita in venis primariis sparse glanduloso-setulosa alioqui glabra, 5- 

 nervata jugo marginali tenuiore venulis laxe retieulatis, ad margines inconspicue 

 undulato-serrulata et distanter ciliolata dentibus ca. 2-2.5 mm inter se distantibus. 

 Inflorescentia 2-3 cm pedunculata, pedunculo glabro circum medium bibracteato 

 bracteis 4-9 mm longis strigulosis trinervatis ; ramuli plerumque 4 verticillati 

 divaricati 3-5 cm longi glabri floribus 3-5 seeundis ; bracteolae ca. 2x1 mm 

 elliptico-obovatae glabrae ad margines vix erosae ad pedicelli basim insertae; 

 pedicelli 3-5 mm longi basim versus glabri ad apicem sparse laxo-setulosi. 

 Hypanthium (ad torum) 2.1-2.5 X 2.3-2.4 mm dense vel modice pilis fragilibus 

 laxis glanduliferis basi incrassatis ad 1.5 mm longis obsitum vix 10-costatum ; 

 calycis tubus 0.4-0.5 mm altus, lobis obverse ellipticis apiee rotundatis et 0.1 mm 

 unimucronulatis extus tuboque dense pilis laxis fragilibus plerumque non 

 glandulosis interdum apicem versus paucibarbellatis 1.5-3.5 mm longis ornatis. 

 Filamenta 2.5-3 mm longa glabra ; antherarum thecae 3.4-4 mm longae subulatae 

 minute uniporosae, appendice dorsali 0.8-1.2 mm longa, appendice ventrali 

 0.8-1 X 0.2-0.4 mm distaliter vix expansa et emarginato-truncata vel trilobulata. 

 Stylus #8-9 X 0.25 mm glaber ; stigma truncatum ; ovarium apice in collum 0.8 

 mm altum marginaliter dense brevissimeque glanduloso-setulosum circum styhim 

 protractum. Fructus ignotus. 



Type. Herb, leaves medium green above and whitish green beneath, calyx red, 

 corolla white, infrequent on rotting logs in talus forest along northeast side of 

 Mt. Ayanganna, upper Mazaruni River basin, Pakaraima Mts., British Guiana, 

 alt. 800-900 m, 16 Aug 1960, Stephen S. Tillett, Carolyn L. Tillett, & Rufas 

 Boyan 45152 (holotype US 2343864). Paratypes. BRITISH GUIANA, Pakaraima 

 Mts. Mt. Ayanganna: talus forest slopes on northeast side, alt. 800-915 m, Till- //, 

 Tillett, & Boyan 45000, 45151. Membaru-Kurupung Trail: rocks in gorge, alt. 

 1000 m, Maguire & Fanshawe 32405. 



All of the previously described genera and species of Bertolonieae have, as 

 far as is known, 2-4-celled ovaries. Boyania would key otherwise to Diplarpea 

 (with long calyx lobes and oblong anthers with a short blunt dorsal calcar) or 

 to Monolena (with glabrous hypanthia and connectives merely tuberculate 



