1957] 



THE BOTANY OF THE GUAYANA HIGHLAND— PART II 



341 



is the only species of this subgenus with a cylindric hypanthium to which the 

 bracteoles are united. These are characteristics of subgenus Apoxypetala but in 

 all other respects D. jenmani belongs with the typical subgenus. It differs from 

 D. fraterna in the type of pubescence and the shape of the wax-granules on the 

 lower surface of the leaflets. D. fraterna also has a longer style, broader stigma, 

 and cupular hypanthium, from which the bracteoles are free. 



II. Section Triplopetala Cowan, sect. nov. 



A sectione Dicymbe 3 petalis stipitatis, duobus haud expansis differt. 

 TYPE species: Dicymbe amazonica Ducke. 



6. Dicymbe amazonica Ducke, Arch. Inst. Biol. Veg. 4:15. 1938. 



This is a very distinctive species in its possession of three petals; on the 

 basis of this character it is considered to represent a distinct section. In most 

 other respects it is quite closely related to the typical section, although it has a 

 rather different facies. Only parts of the type collection, Ducke 35091, have been 

 examined. 



Dicymbe subgenus Apoxypetala Cowan, subg. nov. 



A subgenere Dicymbe petalis singulis vel nullis, sepalis 5, bracteolis ad 

 apicem glande praeditis, ad cylindrici hypanthii basim adhaerentibus differt. 



TYPE species: Dicymbe uaip aruensis Cowan. 



III. Section Eremopetala Cowan, sect. nov. 



A sectione Apoxypetala petalo uno stipitato ceteris haud expansis differt. 

 TYPE species: Dicymbe froesii Ducke. 



7. Dicymbe yutajensis Cowan, sp. nov. 



Arbor 4-8 m alta, ramulis fuscis. Folia bijugata, glabra, petiolis 2 mm longis, 

 leviter compressis, rachibus 18-24 mm longis, supra leviter canaliculars; 

 petiolulis 1.5-2 mm longis, foliolorum laminae elliptico-ovales, coriaceae, 

 margine leviter revoluto, 3-6.5 cm longae, 2-3.5 cm latae, ad basim obtusae vel 

 subobtusae, ad apicem rotundatae leviter retusaeque, laminarum lateribus ambo- 

 bus tenuiter venulosis praecipue infra, costa leviter impressa supra, infra 

 salienti. Inflorescentiae terminales et axillares, composito-corymbosae, minute 

 strigulosae, ca. 8 cm longae; pedicellis 7 mm longis, minuto-strigulosis, bracteo- 

 lis oblongis, navicularibus, 8 mm longis, 4 mm latis, ad apicem umbonato- 

 glandularibus, glande 1 mm longa, obtusa, lateribus ambobus minuto-strigulosis, 

 ad hypanthii basem adharentibus. Hypanthium cylindricum, 3-4 mm longum, 

 leviter minuto-strigulosum, sepala duo adaxilia cohaerentia, 4 mm longa, ca. 

 1 mm lata, subulato-lanceolata, acuto, glabra, cetera 5 mm longa, 1.5 mm lata, 

 subulato-lanceolata, acuta, glabra; petala 5, uno adaxili petaloideo, stipite 4 mm 

 longo, striguloso, lamina ca. 8 mm longa, 5 mm lata, cetera triangularia, 0.7-1 

 mm longa. Stamina 10, libera, filainentis 11.5-12.5 mm longis, ad basim strigu- 

 losis, antheris oblongo-ovalibus, 2 mm longis, 1 mm latis, glabris. Stylus ad 

 basim strigulosus. Ovarium oblongum, 4.5-5 mm longum, 1.5 mm latum, striguloso- 

 velutinum, stipite ad hypanthii murum adnatum, parte libera ca. 0.5 mm longa, 

 striguloso-velutina. Fructus immaturus 6-6.5 cm longus, 2 cm latus, oblongus, 

 leviter strigulosus, 3-4-seminifer. 



TYPE: small bushy tree 4-8 m tall, fruiting only; lvs. 4-foliolate. Frequent on 

 northwest ridge above Camp Yutaje, elev. 1500 m, Serrania Yutaje, Cerro Yutaje, 

 Rio Manapiare, Terr. Amazonas, Venezuela, February 23, 1953, Bassett Maguire 

 & Celia K. Maguire 35379 (NY). 



