ROWLEE; SYNOPSIS OP THE GENUS OCHROMA l6l 



November to February. These species grow in contiguous 



regions and, though they may overlap somewhat in distribution, 



they are nevertheless distinguished by well marked morphological 



characters. 



With the exception of O. limonensis all these species flower 



and fruit in the dry season of their respective regions. In 



northeastern Costa Rica there is no well defined dry season 



and this probably accounts for the exceptional flowering period 



of O. limonensis. 



» 

 Key to vSpecies 



Calyx lobes carinate. Outer sepals triangular acuminate. 



Leaves thin, green on both sides, conspicuously 5 to 7-lobed, glabrous 



or nearly so i. O. concolor. 



Leaves thick, rusty-pubescent, at least beneath, obsoletely 3 to 5- 

 lobed. 



Flowers 10 cm. long 2. 0. lagopus . 



Flowers 15 cm. long or more. 



Calyx tube cylindric 3. 0. limonensis. 



Calyx tube widened upward 4. 0. grandiflora. 



Calyx lobes not carinate. 



Leaves repand-dentate 5. 0. lomentosa. 



Leaves not repand-dentate. 



Calyx lobes triangular, acute, coriaceous. 



Leaves rusty-tomentose on both sides, the hairs 5 to 7- (mostly 



6)branched 6. 0. velutina. 



Leaves glabrous and dark green above, white and stellate- 

 pubescent beneath, the hairs 10 to i5-(mostly i2)branched. 



7. O. bicolor. 

 Calyx lobes elliptic or orbicular, obtuse, herbaceous. 

 Calyx lobes elliptic; leaves densely velutinous beneath. 



8. 0. boliviana. 

 Calyx lobes orbicular; leaves scantily pubescent beneath. 



9. 0. ohtusa. 

 I. Ochroma concolor, n. sp. Barrios balsa. 



A tree attaining 25 meters in height and i meter in diameter, in 

 woodlands developing a long, smooth trunk, in the open a short trunk 

 and a round, symmetrical top ; heartwood in older trees red, wet, and 

 heavy, the wood of young trees white and light; leaves thin and mem- 

 branous, large and conspicuously lobed, with 5 to 7 acute lobes 

 separated by broad, convex sinuses, green and glabrous on both sides 

 except for a few tufts of brownish tomentum on the primary veins 

 beneath; stipules large, ovate, with prominent midribs; flowers 10 

 cm. long, glabrous; calyx tube 6 cm. long, glabrous within; calyx lobes 

 very dissimilar, 2 cm. long, the outer 2 acuminate, with a prominent 



