1963] 



BOTANY OF THE GUAYANA HIGHLANDS PART V 



45 



survey. However, species of adjacent floras which appear infrequently on the 

 fringe of the Guayana area are included; conversely, species typical of areas 

 beyond the Guayana range but found occasionally in the latter are noted. 



Aiouea benthamiana Mez, Jahrb. Bot. Gart. Berlin 5 : 48. 1889. 



Aiouea brasiliensis y glabri flora Meissner in DC. Prodr. 15 1 : 83. 1864, quoad Spruce 2414. 



Type. Prope San Gabriel de Cachoeira, ad Rio Negro, Amazonas, Brazil, 

 Spruce 2414 (isotype, fl. NY). 



Distribution. Tree or shrub growing along the Rio Negro and its tributaries 

 in Brazil and possibly extending into Colombia, with a single collection noted 

 from eastern Brazil in the Amapa region. BRAZIL. Amapa : infrequent in 

 riverine forest on right bank of Rio Amapari, Serra do Navio, Cowan 38596 

 (fr.NY). 



The species is distinctive for the very small, delicate, green or yellow flowers 

 borne in dense clusters at the tips of reddish branchlets of much-branched 

 panicles which are frequently longer than the shining, yellow-green leaves, these 

 usually with undulate margins. According to the collector's note on the above- 

 cited specimen, the fruit is ellipsoid, green, borne in a dark red cupule. 



Aniba castanea C. K. Allen, sp. now Fig. 29. 



Arbor gracilis ad 6 m alt., gemmis gracilibus anguste lanceolatis longo- 

 acuminatis dense minuteque pallide subferrugineo-subsericeis, ramulis atro- 

 brunneis subangulatis, mox striatis ± teretibus, subferrugineo-pubescentibus. 

 Folia alternata, saepe ad apicem ramulorum opposita, petiolis satis robustis 

 pubescentibus, mox glabrescentibus, atratis canaliculars 6-12 mm longis et ad 

 basim 3 mm latis, laminis utrinque glabris, juventute permembranaceis utrinque 

 castaneis, mox-subcoriaceis, supra opaca viridescentibus subtus pallide castaneo- 

 brunneis ellipticis, (8-) 10-18 cm longis et (3-) 4-7 cm latis, ad basim attenuato- 

 cuneatis saepe recurvatis et leviter decurrentibus, ad apicem attenuato-acumina- 

 tis, acumine ad 2 cm longo vel obtuse acuto, penninerviis, costa supra pallide 

 castaneo-brunnea ± impressa, subtus concolor conspicue elevata, nervis ± 5- 

 paribus, juventute tenuissimis inconspicuis utrinque concoloribus, mox subtus 

 conspicue elevatis ad angulo 35° divergentibus, rete venularum juventute 

 utrinque conspicuo mox supra obscuriori. Inflorescentia axillaris subterminalis- 

 que, ut videtur pauciflora, minute pubescens, anguste racemoso-paniculata, 

 pedunculo ad 2 cm longo, ad (post anthesin) 7 cm longa et 2 cm lata. Flores 

 ad 0.8-1 mm longi, minute pubescentes, pedicello gracili 0.3 mm longo ; perianthio 

 suburceolato, lobis ovatis ad 1 mm longis quam tubo crasso duplo longioribus; 

 staminibus fertilibus pubescentibus ser I & II ad 0.7 mm longis, antheris late 

 ovatis, locellis aliquantum parvis apicali-introrsis, connectivo inconspicuo prod- 

 ueto, filamentis ± crassis quam antheris ±: duplo longioribus, ser III sub- 

 rotundatis ad 25 mm longis, locellis satis magnis extrorsis quam filamentis satis 

 crassis triplo brevioribus, biglandulosis, glandulis ± ovatis stipitatis, ser IV 

 abortivo ±0.5 mm longis, pubescentibus ; gynoecio glabro ad 4.5 mm longo, 

 ovario ± ovato-ellipsoideo glabro, st3 T lum gracilem subaequanti, stigmate ± at- 

 tenuato-inconspicuo. Infructescentia matura ? depauperata minute pubescens ad 

 4.5 cm longa. Fructus maturus? in sicco castaneus, oblongo-subrotundatus, 

 obscure apiculatus, ad 12 X 10 mm, cupula in sicco atrato-brunnea cyathiformi 

 glabrata minuto-verruculosa ad 10 mm longa, 15 mm diam. et 5 mm alt., pedicello 

 ±5 mm longo et 2 mm lato subtenta. 



