234 



MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



[VOL. 10 



VENEZUELA. Amazonas: locis humidis prope Javita Orinocensium, Hum- 

 boldt & Bonpland 974 (photo of holotype at B in F, NY) ; bog, Rio Negro, at 

 base of Cerro Cucuy, 2 Mar 1944, J. T. Baldwin, Jr. 3213 (F, US, VEN) ; a lo 

 margo de un camino en la selva de Maroa ; alt. 127 m ; hierba de 15 a 30 cm; 

 alrededor de los arboles; 9 Feb 1942, Llewelyn Williams 14198 (F) ; en la selva 

 alta, tupida de Yavita; alt. 128 m; 24 Jan 1942, Williams 13967 (F) ; cienega de 

 ciperaceas, cerca Jacamin, Rio Casiquiare ; 25 Jan 1958, Vareschi& Madgefau 6740 

 (VEN) ; infrequent in forest near Base Camp, Cerro Sipapo (Paraque) ; alt. 

 125 m ; perennial herb ; flowers white ■ 1 Jan 1949, Maguire & Politi 28061 (NY) ; 

 occasional in sabanita along Yavita-Pimichin trail near Pimichin, Rio Guainia; 

 alt. 120-140 m; 22 Nov 1953, Maguire, Wurdack, & Bunting 36325 (NY) ; fre- 

 quent in sabanita 1 km east of Maroa, Rio Guainia; alt. 125 m; 16 Apr 1953, 

 Maguire & Wurdack 35691 (NY) ; occasional in savanna 0.5 km east of Maroa, 

 Rio Guainia; alt. 130 m ; 6 Oct 1957, Maguire, Wurdack, Keith, & C. K. Maguire 

 41712 (NY) ; Sabana Manacal, Rio Atabapo, 15 km above Guarinumo ; alt. 125 m ; 

 12 Jun 1959, Wurdack & Adderley 12955 (NY). COLOMBIA. Vaupes: frequent 

 in sabanita 0.5-1.5 km north of Puerto Colombia (opposite Maroa) ; alt. 130 m; 

 12 Oct 1957, Maguire, Wurdack, Keith, & C. K. Maguire 41854 (NY). BRAZIL. 

 Amazonas : Boca do I^ana, Estacamento, caatinga baixa ; arbusto, 20-40 cm ; flor 

 branca; 17 May 1948, Black 48-2727 (NY) ; Rio Icana, Tunui ; 1947, J. Murca 

 Tires 1910 (NY). 



This species was originally described by Humboldt, Bonpland, & Kunth in 

 the verbenaceous genus Buchia and later transferred to its proper position in the 

 Rubiaceae as congeneric with Perama by Hooker Alius in Bentham & Hooker's 

 Genera Plantarum. K. Schumann in the Flora Brasiliensis gave it only brief 

 mention, while Standley, in his Rubiaceae of Venezuela (Field Mus. Bot. Ser. 

 7: 475. 1931) knew it only from a photograph of the holotype specimen, likewise 

 describing the species very briefly. 



Some variation is shown in the amount of indument of the lower surface of 

 the leaf-blades, in leaf -shape, and in length of peduncle. In Wurdack & Adderley 

 42955 one specimen of the collection has sessile heads, whereas most of the in- 

 florescences in the same collection are variously pedunculate. Also, in this collec- 

 tion the lower surface of the leaf-blades are only sparsely sericeous to nearly 

 glabrate. There is likewise variation in habit from subacaulescent herbaceous 

 stems to#elongated subligneous ones with elongated internodes. 



2. Perama dichotoma Poepp. & Endl. Nov. Gen. & Sp. 3: 29. pi. 235. 1845; 

 K. Schumann, in Mart. Fl. Bras. 6(6) : 91. pl, 86. 1889. 



Key to the Varieties of Perama dichotoma 



1. Entire lower surface of leaf-blades completely covered with dense hirsutulous pubes- 

 cence, concealing the main nerves. 2c. P. dichotoma var. hirsutula. 

 1 . Lower surface of leaf -blades glabrous to hirsutulous or villous only along the principal 

 nerves, elsewhere glabrous or only sparsely pubescent, the main nerves evident and 

 not concealed by the pubescence. 

 2. Lower surface of leaf-blades glabrous or with appressed inconspicuous hairs 

 0.1-0.5 (-1) mm long; upper surface of leaf -blades with hairs 0.2-1 (-2) mm 

 i on „ 2b. P. dichotoma var. scaposa. 



