232 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN [VOL. 10 



at hand, it is also evident that the differences now manifested can best be ex- 

 pressed as specific taxa. 



Perama Aubl. PL Guian. 1 : 54. 1. 18. 1775. 



This is a genus of annual or perennial, mainly small, herbaceous plants of 

 wide distribution in the Guayana area from the Guianas to Venezuela, and ex- 

 tending south in eastern Brazil to the states of Goyaz, Bahia, and Minas Geraes. 

 The genus has not been treated since the account by Schumann in Martius 's Flora 

 Brasiliensis in 1889 (6°: 87-91). One of the species from Minas Geraes, Brazil, 

 described as new below has been an herbarium name for the past three decades, 

 while another from the same state is as yet inadequately known. 



An interesting feature of the genus is the dimorphism of the corollas of some 

 of the species, especially in P. galioides, in which flowers having long-exserted 

 styles and included anthers on short filaments contrast with those having shorter 

 included styles and stamens on filaments exserted from the orifice. Great variation 

 is exhibited in the pubescence and foliage of the plants as well as habit, leading 

 to many intergrading forms. In general, however, the species are well-character- 

 ized in a distinct, well-marked genus, which is notable in possessing a 2-parted 

 calyx and a circumscissile dehiscent capsule. 



Key to the Species of Perama 



1. Leaves either rosulate and clustered fit the base of the plant, or, if not clustered, 

 commonly 25-90 mm long and 10-25 mm wide ; calyx-lobes ovate or suborbicular- 

 ovate to triangular, the lobes shorter than or only slightly longer than the 

 hypanthium or ovary. 



2. Inflorescence commonly of 2-6 glomerate spikes, rarely solitary; calyx navicular, 

 the lobes 1-1.8 mm long; corolla-tube densely and conspicuously pubescent; 

 leaves crowded at or near the tips of the subligneous or herbaceous, thickened 

 stems. 1. P. plantaginea. 



2. Inflorescence of solitary heads on the branches; calyx segments broadly trian- 



gular to ovate, 0.5-1.2 mm long; corolla-tube sparsely and minutely puberulent 

 to moderately villosulous; leaves rosulate, at the base of the filiform stems. 



2. P. dichotoma. 



1. Leaves borne along the length of the stem from base towards summit, 2-13 mm long, 

 0.2-4.5 mm wide; calyx-lobes setaceous or linear-lanceolate, much longer than the 

 hypanthium or ovary. 



3. Leaves ternate or quaternate. 3. P. galioides. 

 3. Leaves in pairs. 



4. Corolla rose; flowers among the dense mass of leaves in the upper part of the 



* stem; corolla-lobes and stamens 5. 6. P. vellerea. 



4. Corolla yellow; flowers in a definite head terminating the stem or branches of 

 the stem; corolla-lobes and stamens 4. 

 5. Stem simple, monocephalous, 1.5-4 cm tall; all the leaves linear-lanceolate; 

 calyx equaling corolla or nearly so; seeds minutely scrobiculate with super- 

 ficial cells. 4. P. mexiae. 

 5. Stem usually branched and frequently with 2-many heads, rarely simple and 

 monocephalous, 10-40 cm tall; lower leaves commonly ovate to lanceolate; 

 calyx shorter than the corolla-tube; seeds lineolate. 5. P. hirsuta. 



1. Perama plantaginea (H.B.K.) Hook. f. in Benth. & Hook. Gen. PL 2: 148. 

 1873. Fig. 78, A-C. 



Buchia plantaginea H.B.K. Nov. Gen. & Sp. 2: 270. pi. 132. 1819. 



Distribution : at low altitudes in drainage of the upper Rio Negro and Orinoco 

 from the rivers Orinoco, Guainia, and Negro in Venezuela, to the Rio Icana in 

 Amazonian Brazil. 



