1953} 



BOTANY OF THE GUAYANA HIGHLAND 



153 



pales 7-12, frequent, ridge Southwest Escarpment, 1850 m. alt., 30291. Summit 

 Cerro Paru, Terr. Amazonas, Venezuela, January, 1951, Cowan & Wwrclack; 

 shrub 1-3 m. high, flowers yellowish, West Riiu s=»t 2000 m. alt., 31102; shrubs 



0. 2-2.0 m. highj flowers brownish, locally frequent in drier savannas, cumbre be- 

 yond West Rim, 2000 m. alt., 31162. 



This attractive shrub had previously been represented from Cerro Duida only 

 by the type and paratype, Tate 1014 and 415 respectively. Now it has been rather 

 widely collected and studied in the field as shown by the above citations of ex- 

 siccatae from Cerro Huachamacari, separated from Duida by the 20-kilometer- 

 wide valley of the Rio Cunucunuma, and from Cerro Paru about 75 kilometers to 

 the northward on the Rio Paru, tributary of the Rio Ventuari. This species shows 

 little variation throughout its extended range. It was assigned by Blake 28 as the 

 type species of the subgenus Stomal ochaet a Blake of Stenopadus. It is to be 

 questioned if this group, with stiffly erect narrow corolla lobes, can correctly be 

 considered as congeneric with members of the subgenus Eustenopadus, in which 

 the corolla lobes are much broader and prominently coiled. 



Stenopadus in the broad sense is now accredited with twelve species. The fol- 

 lowing key may serve to differentiate them and to indicate their general relation- 

 ship and geography. 



Key to the Species of Stenopadus 



1. Corollas with recurved and coiled lobes which are shorter than the tube (subg. Eus- 



tenopadus Blake). 

 2. Leaves subcoriaceous, not at all reticulate; heads solitary. 



3. Leaves broadly elliptic, strongly pinnate-nerved; known from the 



region of Mt. Roraima only. 1. S. connellii (Baker) Blake. 



3. Leaves obovate to oblanceolate, lateral nerves merely prominulous. 

 4. Heads conspicuously stipitate or contracted at the base; phyl- 

 laries in 10 or more series; leaf blades obovate to broadly ob- 

 lanceolate (10-) 12-25 cm. long, 6-8 cm. wide; presently known 

 only from Cerro Sipapo. 2. S. kunhardtii Maguire. 



4. Heads sessile, not at all stipitate or contracted at the base; phyl- 

 laries in 8 or fewer series; leaf blades oblanceolate (7-)8-12 

 (-15) cm. long, 3.5-6.0 cm. broad; presently known only from 

 Cerro Huachamacari. 3« S. huachamacari Maguire. 



2. Leaves coriaceous, strongly reticulate. 

 3. Branchlets densely pubescent. 



4. Heads 1-3 sessile or on very short peduncles, ca. 15-flowered; 

 outer phyllaries ca. 2.5 mm. wide, inner ca.1.5 mm. wide; leaves 

 obovate 4-10 cm. long; branchlets densely strigillose; known 

 only from Cerro Duida. 4. S. talaumij olius Blake. 



4. Heads apparently solitary, ca. 30-flowered; outer phyllaries 

 3.5-9.0 mm. wide, inner 2-3 ram. wide, branchlets densely stri- 

 gose; leaves obovate 5-12 cm. long; known only from Cerro 

 Duida. 5. S. eurylepis Blake. 



3. Branchlets glabrous; leaves oblanceolate (10-) 15-17 cm. long; pe- 

 duncles sparsely strigillose, usually 5-30 mm. long; heads 2-3, 

 20-25-flowered; small trees of the Upper Rio Caroni, State of 

 Bolivar. 6. S. cardonae Maguire & Lasser. 



1. Corollas with stiff erect lobes which are longer than the tube. 



2. Leaves essentially glabrous, 1-nerved (subg. Stomatochaeta Blake). 

 3. Stems thinly tomentose or strigose, leaves 2 cm. or more in length, 

 petiolate. 



4. Stems tomentose; leaves oval to cuneate, 2-4 cm. long; corollas 

 20-25 mm. long. 

 5. Heads with about 15 flowers. 



Bull. Torrey Club 58: 490. 1931. 



