142 MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 
California: Chesnut & Drew, 1888 (Hy-Am-Pum Valley, Humbolt Co., in pine 
woods). 
27. Horkelia Howellii (Greene) Rydb. 
Potentilla Howellii Greene, Pittonia, 1: 104. 1887. 
Horkelia Howellii Rydb. Bull. Torr. Bot. Club, 25: 55. 1898. 
Howell, Fl. N. W. Am. 1: 181. 
ILtusTrATIoNS: PLare 87, f. 1; dissection of flower, j- 2; pistil, f 3; stamen, f. 4; 
fruiting hypanthium and calyx, f. 5. 
Caudex covered with densely hispid scales (remains of the lower part of the stip- 
ules). Stem slender, strict and simple, more or less red, sparingly villous and somewhat 
glandular. Lower stipules finely twice dissected into filiform, curved and hairy seg- 
ments, the upper 5-10 mm. long, ovate, more or less dissected into oblong or lanceolate 
lobes. Basal leaves numerous, more or less villous, especially the rachis, in age glabrate, 
with 5-20 pairs of small crowded leaflets, these often divided to the base into two or three 
oblong or oval, entire, or 2-3-cleft segments 3-10 mm. long. Cyme open with divergent 
branches but with very short pedicels. Hypanthium cupulate, villous and glandular, in 
fruit 3-4 mm. in diameter; bractlets linear or linear-lanceolate, smaller than the lanceolate 
sepals. Petals white, broadly spatulate, with somewhat erose apex, exceeding the sepals. 
This species and the next differ from all the other species of Huhorkelia intheir leaves, 
the leaflets being, as in Jvesia, divided to near the base and more or less imbricated. 
The structure of the flowers is almost the same as in the preceding species. It is appar- 
ently a rare, or at least local, plant of southwestern Oregon. Specimens seen : 
Oregon: Thomas Howell, 1884 and 1887; T. S. Brandegee, 1885 (Waldo); L. F. 
Henderson, No. 1407, 1887 (Merlin). 
$6. SERICATAE. 
28. Horkelia sericata Wats. 
Horkelia sericata Wats. Proc. Am. Acad. 20: 364. 1885. 
Rattan, An. Key W. Coast Bot. 52; Howell, Fl. N. W. Am. 1: 181. 
Potentilla sericata Greene, Pittonia, 1: 104. 1887. 
ILLusTRATIONS: PLATE 81, f.6; dissection of flower, f. 7; pistil, f. 8; stamen,f. 9; 
fruiting hypanthium and calyx, f. 20. 
Caudex covered with densely hirsute scales. Stems several, very slender, strict and 
simple, somewhat villous aad tinged with red. Stipules lanceolate, about 5 mm. long, 
