92 
MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 123 
$5. HIRSUTAE. 
Resembling somewhat the preceding group, but with more numerous and often dis- 
sected leaflets, broader filaments, and lower stipules which are once or twice pinnately dis- 
sected into linear or filiform hairy segments. 
Cyme fastigiately corymbose. 
Leaves oblong-cuneate, 2—5-toothed at the apex. 
Plant silky ; leaflets about 4 pairs. [22. H. congesta. | 
Plant hirsute ; leaflets 4-10 pairs. 23. H. hirsuta. 
Leaflets divided to near the base into linear segments. 
Stem more or less glandular ; segments linear, acute, 1-2 mm. wide. 24. H. daucifolia. 
Stem silky-villous, not glandular ; segments narrowly linear, less than 1 mm. wide. 
25. H. carwifolia. 
Cyme’ open and lax. 
Leaflets cuneate, cleft half their length at the apex into oblong-acute segments. 
26. H. laxiflora. 
Leaflets divided to the base into oblong or oval segments. 27. H. Howellit. 
$6. SERICATAE. 
This group contains a single species somewhat resembling the last one of the pre- 
ceding group, but the stipules are not dissected. Cyme lax and few-flowered. Leaflets 
densely white-silky, crowded as in most [vesiae. 
One species. 28. H. sericata. 
Subgenus HorKELIELLA. 
$7. PURPURASCENTES. 
Stem slender, erect and strict, eyme open. Leaflets very numerous, over 20 pairs. 
Hypanthium campanulate ; sepals reflexed in anthesis. Petals strap-shaped. Stamens 
20, in three series, the inner (antipetalous) ones the shortest; filaments all lanceolate. 
Pistils rather numerous. 
In the numerous leaflets and the 20 stamens the group approaches Jvesia, but the 
floral structures are otherwise exactly asin Horkelia, especially the Californicae group. 
Plant 3-4 dm. high, smooth ; leaflets 5-8 mm. long. 29. H. pinetorum. 
Plant 1-2 din. high, densely pubescent ; leaflets 2-8 mm. long. 30. H. purpurascens. 
