200 



ROSACEAE 



Acad. 24:11 (1925). Var. clevelandii Jepson, Man. 495 (1925) ; M. & J. I.e., 24:12 (1925). 

 P. clevelandii Greene, Pitt. 1 :102 (1887), type loc. Laguna, e. San Diego Co., Cleveland. UorTcelia 

 clevelandii Evdb. Bull. Terr. Club 25:54 (1898); Mem. Dept. Bot. Columbia Univ. 2:129, pi. 

 Gl (1898). U. calif ornica Bdg. Zoe 4:204 (1893). 



41. P. stenoloba Greene. Sonojia Honey-dew. (Fig. 164.) Stems ascend- 

 ing or erect, 5 to 12 (or 15) inches high; herbage villous but more or less green, 

 glandular-aromatic; leaves pinnate, the basal with blades I14 to 7 inches long; 

 petioles i/o to 2I/2 inches long; 

 leaflets 17 to 31, cuneate-obo- 

 vate, 2 to 4 lines long, cleft I/2 

 to % the way into about 4 lin- 

 ear lobes; cymes compact, the 

 clusters subcapitate on the 

 ends of the branches; flowers 

 3 to 31/^ lines wide; calyx-tube 

 shallow, truncate at base, 1 to 

 iy2 lines wide, % to % line 

 high; calyx-lobes linear; petals 

 white, euneate or oblanceolate, 

 emarginate, 1% to 2l^ lines 

 long; stamens 10; filaments di- 

 lated (triangular- to narrow- 

 lanceolate) ; achenes many, 

 smooth or nearly so. 



Sandy soil of valleys or 

 ridges, 150 to 2000 feet : Coast 

 Kanges in Sonoma Co., Marin 

 Co. and San Luis Obispo Co. 

 Apr.-June. 



Geog. note. — Potentilla steno- 

 loba Greene occurs apparently in 

 only a few scattered localities. The 

 type of Potentilla micheneri Greene, 

 a form at somewhat higher altitude, 

 has crowded leaflets, thus approach- 

 ing rather closely the condition in 

 the subgenus Ivesia. Other collec- 

 tions of this form from the same 

 localitj^ (Mt. Tamalpais, Michener 

 4" Bioletti) show much less reduc- 

 tion of leaflets and differ mainly 

 from typical P. stenoloba in the 

 somewhat broader bractlets and the 

 shorter leaflet-segments, characters 

 too slight to serve as the basis of a 

 variety. The collection from near 



Sebastopol (Crum 1091) was taken from a colony growing in dry sandy soil. Although this 

 species has at times been described as non-glandular, the Sebastopol plants were markedly glandu- 

 lar, exhaling the very characteristic Horkelia odor. The root-crown in this species develops heavy 

 horizontal branches resembling rootstocks. From these structures arise stolons 6 to 14 inches long. 



Locs. — Laguna, near Forestville, Sonoma Co., M. S. Baker 3005c; Sebastopol, Sonoma Co., 

 Crum 1091; Mt. Tamalpais, K. Brandegee; San Luis Obispo, Curran. 



Eefs. — Potentilla stenoloba Greene, Erythea 3:36 (1895). EorTcelia fusca var. tenuiloha 

 Torr. Pac. R. Rep. 4:84 (1857), type loc. laguna of Santa Rosa Creek, Bigelow. H. tenuiloha 

 Gray, Proc. Am. Acad. 6:529 (1865). P. tenuiloha Greene, Pitt. 1:105 (1887) ; Jepson, Fl. W. 

 Mid. Cal. 283 (1901), ed. 2, 209 (1911), Man. 493 (1925), not P. tenuHoba Jord. (1852). P. 

 micheneri Greene, Erythea 1:5 (1893), type loc. Mt. Tamalpais, Michener. Horkelia micheneri 

 Eydb. Bull. Torr. Club 25:54 (1898) ; Mem. Dept. Bot. Columbia Univ. 2:127, pi. 59 (1898) in 

 part. P. tenuiloha var. micheneri Jepson, Fl. W. Mid. Cal. 283 (1901), ed. 2, 210 (1911). 



Fig. 164. Potentilla stenoloba Greene, a, habit, 

 X V2 ; b, pair of leaflets, X 2^4 ; c, long. sect, of fl., X 5; 

 d, stamens, X 10. 



