258 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN | VOL. 10 



on outside with grayish margins, inside brown with dark purple-blackish streaks, 

 margined gray; anthers grayish-brown; 7 Mar 1962, J. A. Steyermark & L. 

 Aristeguieta 25 (holotype VEN, isotype NY); same locality; leaves mostly 

 in 3's; tree 15 m; leaves erect-ascending, coriaceous, deep green above with 

 midrib and nerves raised above; 19 Apr 1960, Steyermark & Nilsson 326 

 (paratype NY, Upssala, VEN) ; vicinity of km 131-132, in dwarf forest on 

 summit of plateau in sandstone soil, between Luepa and Cerro Venamo; alt. 

 1300 m; 10 Mar 1962, Steyermark & Aristeguieta 92 (paratype NY, VEN). 



This species, and the newly described P. eglandulosum Steyerm. of British 

 Guiana, possess the largest capsules and seeds thus far known of any of the 

 species of Platycarpum. Although resembling the size and shape of the fruits 

 of P. eglandulosum, P. rugosum has the outer surface of the pericarp more 

 conspicuously areolate-rugose with large areoles, whereas in P. eglandulosum 

 the outer surface of the pericarp is more finely areolate with the areolations less 

 prominent. Moreover, the lower leaf surface of P. eglandulosum has a different 

 type of pubescence, this being of a dual nature consisting of a soft, dense, villous 

 type covering a minutely tomentulose surface in the reticula between the veins, 

 whereas in P. rugosum the pubescence consists of just one type of long strigose 

 hairs, the reticula between the veins lacking the tomentulose vestiture but with 

 a glabrous surface minutely white-puncticulate. The upper surface of the leaf- 

 blade in P. rugosum is glabrous or sparingly strigose or scabro-puberulent, but 

 in P. eglandulosum is more densely pilose. 



The petiolar glands in P. rugosum are peculiar for the genus. Instead of the 

 occurrence of one gland at or near the base of the ventral side of the petiole, 

 the more usual condition found, there are instead two small glands attached 

 laterally on the petiole 2-4.5 mm above its base in addition to the usual single 

 gland found at the very base of the petiole. Thus, three glands may be present 

 and associated with each petiole in this species. 



Although dozens of trees were observed in fruiting stage at the time of the 

 second visit to the area, only a few possessed inflorescences. In those trees where 

 some inflorescences were still extant, all flowers were small, in fact, the smallest 

 size of any species of the genus. Whether this is a normal condition, or rather 

 represents late or aborted stages of flowering, can be decided only by future 

 collections taken in full anthesis. In the short, contracted type of inflorescence 

 which it possesses, P. rugosum suggests P. rhododactylum, a species having 4 

 instead of 5 calyx-lobes, smaller fruits, and glaucous or glaucescent nearly 

 glabrous lower leaf surfaces. 



10. Platycarpum eglandulosum Steyermark, sp. nov. 



Arbor 15-20 m ; ramulis novellis hirsutulis ; foliis ternatis coriaceis petiolatis, 

 laminis ellipticis vel elliptico-oblanceolatis apice obtusis vel subacutis in petiolum 

 2-8 mm longum brunneo-hirsutulum cuneatim angustatis, 10-19.5 cm longis 3-6.5 

 cm latis, supra scabrido-pilosis pilis pallidis, subtus pallidioribus conspicue 

 molliter villosis pilis brunneis vel pallidis vetustioribus magis parce pilosis 

 venularum reticulo minutissime dense albo-tomentello inter ■ reticulum, nervis 

 lateralibus utroque latere 17-21 eis et costa media elevatis; petioli glandulis 

 nullis vel obsoletis ; floribus ignotis ; capsulis compressis rotundato-obreniformibus 

 4.5-5.5 cm latis 3.8-4.7 cm altis, valvis 4 mericarpiis lignosis 1.5-2 mm crassis 

 extus ferrugineis vel fuscis areolatis minute tomentulosis ; seminibus maturis in 

 quoque loculo 2 elliptico-sublunatis 4.2-4.8 cm longis ca. 2.5 cm latis (altis) 



