1963] 



BOTANY OF THE GUAYANA HIGHLANDS PART V 



155 



Both C. reticulata and the more distantly related C. vaupesana Wurdack have 

 hypanthia and calyptras setose. The leaf blades of C. neblinae (as also C. retic- 

 ulata) are strikingly similar to those of Graff enrieda rupestris Ducke ; vegeta- 

 tively G. rupestris may be distinguished by the strigose or appressed-setose 

 vegetative buds and immature petiole apices. 



Maguireanthus Wurdack, gen. nov. 



Tribus Bertolonieae. Pubescentia stellata. Flores 5-meri. Stamina isomorphica ; 

 antherae oblanceolatae, connectivo ad basim prolongato dorsaliter breviter ap- 

 pendicular. Ovarium 3-loculare. Genus monotypicum. 



Maguireanthus ayangannae Wurdack, sp. nov. Fig. 66, d-i. 



Simplicaulis erecta ad 25 cm alta ; caulis petiolis laminis inflorescentia 

 hypanthiisque dense stellato-puberulus, pilis pallidis ramulis plerumque 4-6 

 gracilibus ca. 0.3 mm longis. Folia opposita aequalia; petioli 1.5-5 cm; lamina 

 8-12 X 6-8 cm ovata apice hebeti-acuta basi plerumque truncata membranacea, 

 supra sparsissime strigulosa pilis simplicibus ad 1 mm longis ad margines 

 undulato-denticulata et ciliolata ciliis simplicibus 0.3-0.4 mm longis et 1-2 mm 

 inter se distantibus pubescentia alioqui stellata, 7-plinervata jugis 1-2 mm et 

 3-8 mm et 7-19 mm supra basim insertis supra planis et glabris subtus leviter 

 elevatis nervulis laxe (ca. 4x4 mm) reticulatis. Pedunculus 2-8 cm longus apice 

 cum ramis duobus recte divaricatis secundifloris 2.5-10 cm longis. Flores 5-meri 

 breviter (ca. 1 mm) pedicellati ; hypanthium (ad torum) 2x3.5 mm (alis 

 exclusis) 10-alatum alis antesepalis ca. 1 mm et intersepalis ca. 0.3-0.5 mm 

 eminentibus; calycis tubus 1 mm altus, lobis 0.8 X 1.5 mm late triangularibus 

 apice late hebeti-acutis. Petala 5.4-5.8 X 2.3-2.4 mm spathulata apice hebeti-acuta 

 glabra non ciliata. Antherarum thecae 2.3-2.4 mm longae basim versus attenuatae 

 apice 0.5 mm latae poro 0.25 mm diam, connectivo sub thecis ad filamenti in- 

 sertionem 0.8 mm prolongato dorsaliter cauda 0.3-0.4 mm longa lanceolata hebeti- 

 acuta descendente ornato; filamenta 3-3.1 mm longa glabra. Stylus 6.2 X 0.4-0.6 

 mm glaber; stigma 0.6 mm diam vix expansum truncatum; ovarium glabrum 

 apice in collum carnulosum 0.4-0.5 mm altum prolongation. Fructus ca. 5 mm 

 longus ; semina 0.6 X 0.25 mm anguste pyramidata imperspicue papillosa. 



Type. Herb, flowers white^ occasional in creek beds, montane slopes of Mt. 

 Ayanganna, British Guiana, alt. 1000-1500 m, 5-6 Feb 1955, Bassett Maguire, 

 W. M. C. Bagshaw, & Celia K. Maguire 40579 (holotype US 2342569). 



The general aspect of Maguireanthus, along with the ventrally exappendic- 

 ulate stamen connectives, suggests Bertolonia or Salpinga; neither of these genera 

 shows the relatively long connective prolongation nor the anther shape of the 

 new genus. Although habit variation within Macrocentrum is great, the con- 

 nective prolongation is always much shorter than the dorsal appendage. In 

 both pubescence type and inflorescence, Maguireanthus differs from all other 

 Bertolonieae. 



Tryssophyton Wurdack, gen. nov. 



Tribus Bertolonieae. Flores 4-meri. Stamina in dimensionibus anisomorphica 

 in forma ut in Marcetia. Ovarium 4-loculare superum lobulis membranaceis 4 

 coronatum. Genus monotypicum. 



