MEMOIKS FBOM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 155 



47. Horkelia saxosa (Lemmon). 



Potentilla saxosa Jjemmon ; Greene, Pittonia, 1: 171. 1888. 



Perennial, slender, about 3 dm. high, pubescent and viscid-glandular ; leaves pinnate ; leaflets 

 5-7 pairs, reniform-flabelliform, 1-1.5 cm. long, cleft to the middle into oblong acutish segments. 

 Cyme open. Hypanthium saucer-shaped. Petals yellow, spatulate-oblanceolate. Stamens 20-30; 

 filaments filiform. Pistils 8-10. 



It resembles H. Baileyi in habit, biit differs in the broader leaflets, and the numerous stamens. 

 In this respect and by the fact that the open space between the stamens and pistils is rather narrow, it 

 approaches Potentilla proper in the structure of the flowers. 



Lower California: Lemmon and wife, 1888 (San Eafael Mountains in crevices of rock); C. R. Or- 

 cutt, N"o. 650, 1882 ; 1883. 



3. STELLARIOPSIS. 



Potentilla § Stellariopsis Baillon, Hist. PI. 1: 370. 1867-9. 



Hypanthium saucer-shaped, small. Bractlets, sepals and petals 5. Petals white, 

 elliptic or round-ovate, white, slightly unguiculate. Stamens 15, inserted on the mar- 

 gin of the disk, separated some distance from the pistil ; filaments filiform, long ; anthers 

 purplish, didymous, obcordate, each half nearly pear-shaped, dehiscent by a subterminal 

 pore. Pistil single, surrounded by numerous bristles ; style long and slender, terminal. 

 Mature achene very large for the size of the fiower, at last assuming a more or less hori- 

 zontal position. Seed inserted near the base of the style, pendulous and anatropous. 



The genus contains a single species, native of California, of very peculiar habit and 

 wormlike silky leaves. The general structure of the flower is intermediate between 

 Potentilla and Horkelia {Ivesia), from which genera it differs by the single pistil and the 

 structure of the anthers. 



I. Stellariopsis santalinoides (Gray). 



Ivesia santalinoides Gray, Proc. Am. Acad. 6: 531. 1865. 



Gray, Proc. Am. Acad. 7 : 339 ; Wats. King's Rep. 5 : 448 ; Brewer & Wats. Bot. 

 Cal. 1: 183 ; Rothrock, Wheeler's Exp. 4 : 360 : Rattan, An. Key W. Coast Bot. 52. 



Potentilla santalinoides Greene, Pittonia, 1 : 106. 1887. 



Greene, Fl. Fran. 1 : 69. 



Illustrations: Plate 95, f. 1-2; dissection of flower, /. 3; pistil, /. 4; stamen, 

 /. 5; fruiting hypanthium and calyx, /. 6. 



Root deep, perennial, not very thick, crowned with a short erect caudex, which is 

 densely covered with hairy scales. Stems several, erect, much branched, more or less 

 silky-villous on the lower portion with long white spreading or reflexed hairs. Stipules 



