1953] 



REVISION OF MACROLOBIUM 



271 



long; sepals 5-5.5 mm. long; bracteoles 6.5 mm. long, 3 mm. wide, minutely puberulous 



externally; ovules 5. Eastern Peru 26. M. klugii. 



50. Leaves mostly unijugate but some bijugate, the leaflets 6.5-9.5 cm. long, subarcuate, 

 elliptic, the petioles 13-18 mm. long; inflorescence axis glabrous, the pedicels 6-8 

 mm. long; sepals 7-8 mm. long; bracteoles 10-11 mm. long, 5 mm. wide, glabrous; 

 ovules 1-2. Upper Rio Negro 35. M. palustre. 



Section 2. Stenosolen Harms, Repert. Nov. Sp. 3:51. 1906. 



Bracteoles opening incompletely on the adaxial side of the flower, opening 

 completely abaxially; hypanthium long-cylindric; sepals four, equal; petal sessile 

 or with a very short claw; gynophore inserted at top of the adaxial wall of the 

 hypanthium. 



TYPE Species: Macrolobium stenosiphon Harms, Repert. Nov. Sp. 3: 51. 1906. 



Key to the Species of Section 2. Stenosolen 



1. Leaves 2-30-jugate 2. 



1. Leaves unijugate 4. 



2. Leaves 20-30-jugate, the leaflets subfalcate-lanceolate , mucronate-acuminate, with se- 



riceous marginal band on upper surface; hypanthium 18-24 mm. long; sepals 18—22 mm. 

 long; petal 30-45 mm. long 39. M. stenosiphon. 



2. Leaves 2-13-jugate, the leaflets oblong, lanceolate-oblong, or elliptic, obtuse or bluntly 



acuminate, glabrous or ciliolate on margin; hypanthium, sepals and petal much shorter. 



• ; ; ; 3 - 



3. Leaflets elliptic, in 2-4 pairs; inflorescences cauliflorous, glabrous; ovary glabrous. 



Northern Trinidad 41. M. trinitense. 



3. Leaflets oblong or lanceolate-oblong, in 5-13 pairs; inflorescences terminal or axillary, 



pubescent or the pedicels glabrous; ovary pubescent throughout or only marginally. 

 Foothills of Andes in Colombia and Venezuela 40. M. colombianum. 



4. Leaflet strongly asymmetrical at base, the lower side rounded to subcordate, the upper 



side tapering 5. 



4. Leaflet cuneate at base or nearly so 8. 



5. Sepals 10—13 mm. long; hypanthium minutely puberulous. State of Aragua, Venezuela. . 



6. 



5. Sepals 17-22 mm. long; hypanthium glabrous. Southern Panama or Colombia 7. 



6. Petal blade 30 mm. long; leaflets oblanceolate-elliptic, bluntly acute; hypanthium 9-12 



mm long; bracts 2-3 mm. long 45. M. floridum. 



6. Petal blade 20 mm. long; leaflets elliptic-oval or broadly oblanceolate, broadly rounded; 



hypanthium 6.5-9.5 mm. long; bracts 1-1.5 mm. long 46. M. obtusum. 



7. Petal 28 mm. long, 12 mm. wide, sessile, glabrous; hypanthium 14 mm. long on a 4.5 



mm. stipe; bracteoles 17 mm. long, 6.5 mm. wide, minutely puberulous on outer surface; 

 leaflets elliptic, bluntly acuminate 47. M. archeri. 



7. Petal 47 mm. long, 15 mm. wide, the claw 5 mm. long, strigulose within on costa in the 



lower portion of petal; hypanthium 10 mm. long on a 3 mm. stipe; bracteoles 12 mm. 



long, 4 mm. wide, glabrous; leaflets oblanceolate, caudate-acuminate 



48. M. pittieri. 



8. Leaflets 4-10 cm. long, sessile, epunctate; sepals oblanceolate; ovary densely puberu- 



lous throughout 42. M. stenocladum. 



8. Leaflets 13.5-33 cm. long, usually petiolulate, punctate beneath, sometimes minutely 



so; sepals oblong; ovary puberulous marginally with lateral surfaces glabrous or mi- 

 nutely granular-puberulous 9. 



9. Pedicels 2.5-5 mm. long; bracteoles 9-13 mm. long; hypanthium 6-11 mm. long on a 



stipe 2.5-5.5 mm. long, minutely puberulous; sepals 10.5-15 mm. long, 3-5.5 mm. 

 wide; petal unguiculate, 24-34 mm. long; ovary minutely granular-puberulous on lateral 



surfaces. Western Peru and Colombia 43. M. ischnocalyx. 



9. Pedicels 0.5-1 mm. long; bracteoles 5.5—7.5 mm. long; hypanthium 3-4 mm. long on a 

 1 mm. stipe, glabrous; sepals 5.5-8.5 mm. long, 1-3.5 mm. wide; petal sessile, 11.5- 

 13.5 mm. long; ovary glabrous on lateral surfaces. Northwestern Panama and western 

 Colombia 44. M. modicopetalum. 



1. Macrolobium taxifolium Spruce ex Benth. in Mart. Fl. Bras. 15(2): 224. 1870. 

 Vouapa taxifolia (Spruce ex Benth.) Taub. Bot. Centralbl. 47: 394. 1891. 



