292 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN [Vol. 8, No. 4 



Key to the Varieties of Macrolobium discolor 



1. Leaflets microscopically granulose-ceriferous on lower surface, margins narrowly in- 

 volute; bracts 4.5-5 mm. long; bracteoles 8.5-12 mm. long; ovary pilosulose margin- 

 ally 2. 



1. Leaflets pallid beneath but not granulose-ceriferous, margins plane; bracts 2.5 mm. 



long; bracteoles 5.5-6.5 mm. long; ovary villose marginally, .. 15c. var. egranulosum. 



2. Undersurface of leaflets glabrous or sometimes with very few hairs on costa base; se- 



pals dimorphic, adaxial pair 2.5-3 mm. long 15b. var. discolor. 



2. Undersurface of leaflets sparingly pilosulose; sepals homomorphic, adaxial pair 4—4.5 

 mm. long 15a. var. caudiculatum. 



15a. Macrolobium discolor var. caudiculatum (Ducke) Cowan, comb. nov. Figure 5b. 



Macrolobium caudiculatum Ducke, Trop. Woods 65: 28. 1941. 



Small tree, the branchlets pilosulose and puberulous. Stipules 5 mm. long, 1 

 mm. wide, lanceolate, acute, short-pilosulose externally, glabrous within. Peti- 

 oles 4-5 mm. long, both the petioles and the rachis pilosulose and puberulous. 

 Leaf blades 4-6-jugate, the pairs 20-25 mm. apart. Leaflets 3-5 cm. long, 1.5-2.5 

 cm. wide, the base subobtuse, the apex slightly refuse, the lower surface spar- 

 ingly pilosulose. Inflorescence 5.5 cm. long, the axis pilosulose and puberulous, 

 terminal or axillary; bracts 5 mm. long, triangular-lanceolate, the outer surface 

 puberulous; pedicels 2-2.5 mm. long; bracteoles broadly oval, 9.5 mm. long, 4.5 

 mm. wide, puberulous externally, sparingly strigulose within. Sepals 4-5.5 mm. 

 long, lanceolate or oblong, sparsely ciliolate. Petal not seen. Filaments villosu- 

 lose in the lower part. Ovary short-pilosulose on the margins, the gynophore 3 mm. 

 long, puberulous, inserted at the base of the hypanthium. Fruit unknown. 



Type Collection: A. Ducke (H.J.B.R. No.) 24064, "baixo Uaupes," Amazonas, 

 Brazil, Nov. 1932 (HOLOTYPE RB). Known only by the type collection. 



15b. Macrolobium discolor var. discolor. Figure 5b. 



Vouapa discolor (Benth.) Taub. Bot. Centralbl. 47: 393- 1891. 

 Vuapa discolor (Benth.) Kuntze, Rev. Gen. 1: 213- 1891. 



Branchlets pilosulose. Petioles (2-)5-10 mm. long, pilosulose. Leaf blades 

 (3-)4-5(-7)-jugate, the pairs 10-30 mm. apart, the rachis pilosulose. Leaflets 

 (1.5-)4-5(-7) cm. long, 1-3.5 cm. wide, the apex retuse, the lower surface granu- 

 lose-ceriferous, glabrous or rarely puberulous on costa base, the costa impressed 

 above. Inflorescence (3-X>(-13.5) cm. long, terminal, the axis puberulous; bracts 

 4 mm. long, 1.5 mm. wide, lanceolate, puberulous externally on the costa and at 

 the apex, sparsely puberulous within; pedicels 2-5 mm. long, puberulous; bracte- 

 oles 8.5-12 mm. long, 3.5-6 mm. wide, more or less elliptic, glabrous within. Se- 

 pals free or united basally, lanceolate, acute to long-acuminate, the adaxial pair 

 2.5-3 mm. long, 1-1.5 mm. wide, the others 5-7 mm. long, 1-3 mm. wide. Petal 

 blade (3.^-)5.5-7 mm. long, the claw (6.5-)9-12.5 mm. long. Ovary pilosulose on 

 the margins, 4-6-ovulate, the gynophore pilosulose, inserted on the adaxial hy- 

 panthial wall at or near the apex. Fruit unknown. 



Type Collection: R. Spruce 3755, "In syivis humilioribus secus fl. Guainiam," 

 upper Rio Negro, Venezuela, Nov. 1854 (HOLOTYPE K). 



Additional Specimens: VENEZUELA: Amazonas: Cerro Sipapo, near base camp, above 

 Cano Cuao, Dec. 1948, Maguire & Politi 27978 (GH, IAN, NY, P, RB, U); savanna near 

 Base Camp, Cerro Sipapo, Feb. 1949, Maguire & Politi 28819 (G, NY, US, VEN), 28823 

 (F, G, IAN, K, MO, NY, US, VEN); Esmeralda Savanna, Alto Orinoco, Sept. 1944, Steyer- 

 mark 58402 (F, VEN); Esmeralda, Grand Savanna-Sect. 1, Nov. 1928, Tate 289 (NY, US). 



15c. Macrolobium discolor var. egranulosum Cowan, var. nov. Figure 5b. 



Arbuscula 2-3 m. alta, ramulis pilosulis. Stipulae 5 mm. longae, subulatae vel 

 subulato-lanceolatae, intus glabrae, extus pilosulae. Petiolus 2-5 mm. longus, 



