102 APOCYNACEAE 



Loamy slopes or rocky rifts : Southern California mountains, 5000 to 9000 feet; 

 North Coast Ranges from Napa Co. to Siskiyou Co., 300 to 5500 feet; Sierra Nevada 

 from Tulare Co. to Modoc Co., 3000 to 9000 feet. East to Nevada, north to Idaho 

 and British Columbia. June-July. 



Note on variation.^ — In the higher Sierra Nevada the herbage is commonly glabrous. At 

 lower altitudes in the Coast Eanges or Sierra Nevada the plants may be (a) glabrous (Whitmore, 

 Shasta Co., Alma Weigart) ; or (b) the stems and petioles may be puberulent, the leaves glabrous 

 or essentially so (Hamilton sta., Mariposa Co., A. L. Grant 831) ; or (c) the plants may be pu- 

 berulent (St. Helena, Jepson 14,622) ; or (d) the plants may be puberulent save the upper side 

 of the leaves or the upper side be provided with extremely scattered microscopic hairs (betw. 

 Dyers ranch and Hawkins Bar, New River, Jepson 1987). Pubescence or various degrees of it or 

 the lack of it is not a.ssociated with any other characters. Between Marble Fork Kaweah River 

 and Round Mdw. we observed two plants growing side by side which were in every apparent way 

 identical save that one was glabrous and the other puberulent {Jepson 696). 



On the erect stems of Apocynum cannabinum the leaves stand in rather closely erect pairs, 

 whereas on the diffuse branches of Apocynum pumilum the spreading leaves display their upper 

 surface to the sky. High temperatures may bring a marked change in this position in the case 

 of A. pumilum. On exposed ridges or dry slopes the leaves borne on spreading stems m.ay take 

 up a hanging or pendulous position during the high insolation period of midsummer days. The 

 assumption of such a protective position was observed to great advantage on the Devil's Back- 

 bone near Trinity Summit in July, 1902. The opposite leaves turn directly downward, back to 

 back, and thus lessen transpiration, as was also noted on the Marble Pork Kaweah River in June, 

 1900. 



Locs. — S. Cal. mts. : Palomar Mt., Jepson 14,626; Tahquitz, San Jacinto Mts., Sail; Pre- 

 dalba, San Bernardino Mts., Airams 2775 ; Vincent Gulch. San Gabriel Mts., Peirson 882. North 

 Coast Ranges : Howell Mt., Napa Range, Jepson 14,024 ; Lyons Valley, M.iyacamas Range, Jep- 

 son 2252 ; Asa Bean Plat, Middle Eel River, se. Trinity Co., Jepson 14,620 ; Devil's Backbone, near 

 Salmon Summit, Jepson 2097 ; Cold Spr., Woolly Creek, w. Siskivou Co., Butler 77 ; Sisson, Jepson 

 14,625 ; Yreka, Butler 75. Sierra Nevada : Wolverton Creek, Tulare Co., W. Fry 369 ; Bubbs Creek, 

 Kings Canon, Jepson 808 ; Huntington Lake, Jepson 12,984 ; Hazel Green to Big Mdws., Mariposa 

 Co., Jepson 14,623; Kennedy Mdws., Tuolumne Co., A. L. Grant 171; Bear Valley, Nevada Co., 

 Jepson 14,621 ; Pioneer sta.. North Fork Yuba River, Jepson 16,785 ; Martin Sprs., Eagle Lake, 

 Brown 4' Wieslander 3; Butte Lake, Lassen Co., J. Grinnell; Mt. Bidwell, Modoc Co., Manning. 



Refs. — -Apocynum pumilum Greene, Man. Reg. S. F. Bay 240 (1894) ; Woodson, Ann. Mo. 

 Bot. Gard. 17:101 (1930). A.androsaemifolium\3.T. pumilum Gray, Syn. Fl. 2:83 (1878), "Cali- 

 fornia to British Columbia"; Jepson, Fl. W. Mid. Cal. 380 (1901)", ed. 2, 321 (1911), Man. 769, 

 fig. 755 (1925). A. rhomloideum Greene, Pitt. 5:60 (1902), type loc. Napa Valley floor e. of St. 

 Helena, Jepson 14,625. A. viarum Hel., Muhl. 2:110 (1906), type loc. Nevada City, Heller 8110. 



A. androsaemifolium var. incanum DC, Prod. 8:439 (1844) ; Woodson, Ann. Mo. Bot. Gard. 17:91 

 (1930). A. stenolohum Greene, Lflts. 2:183 (1912), type loc. Davis Creek, Modoc Co., M. M. 

 Austin. A paniculatum Greene, Lflts. 2:183 (1912), type loc. Warner Creek, Modoc Co., S. M. 

 Austin. A pulchellum Greene, Lflts. 2:186 (1912), type loc. "mountain meadows of Lassen Co.," 



B. M. Austin. A. rotundifolium Greene, Lflts. 2:186 (1912), type loc. Placer Co., Carpenter. 

 A. arcuatum Greene, Lflts. 2:187 (1912), tj'pe loc. Gravelly Valley, South Fork Eel River, n. Lake 

 Co., Jepson. A. eercidium Greene, Lflts. 2:188 (1912), type loc. Fort Bidwell, Modoc Co., Man- 

 ning. A. austinae Greene, Lflts. 2:188 (1912), type loc. Lassen Creek, Modoc Co., R. M. Austin. 

 A. luridum Greene, Lflts. 2:189 (1912), type loc. Lassen Creek, Modoc Co., B. M. Austin. A diver- 

 sifolium Greene, Lflts. 2:189 (1912), type loc. Fredalba, San Bernardino Mts., Abrams. A. an- 

 drosaemifolium var. nevadense Jepson, Man. 769 (1925), type loc. Huntington Lake, A. L. Grant 

 1124. 



3. A. cannabinum L. Indian Hemp. Stems erect, rather strict, simple below, 

 2 to 4 feet high ; herbage of a light almost yellowish green, glabrous or sometimes 

 more or less puberulent; leaf-blades oblong or oval to oblong-ovate or lanceolate, 

 abruptly acuminate, obtuse at base or the lower often subcordate, 2i/2 to 414 inches 

 long, sessile or short-petioled; calyx-lobes a little exceeding the corolla-tube; co- 

 rolla greenish, 11/4 to 1% lines long; follicles pendulous, 3 to 3^2 inches long. 



Stream- and river-banks and moist flats, ^250 to 7500 feet : vndely distributed 

 in California, more common toward the interior. Ea,st to Florida and Nova Scotia, 

 north to British Columbia. May-July. 



Field note.- — The herbage of Apocynum cannabinum is poisonous to cattle. The native 

 tribes used the mature stems for making rope and cord ; from their fibres they manufactured a 

 superior product. Apocynum pumilum Greene was also used as a source of fibre. 



