94 MALVACEAE 



6. Malvastrum arcuatum (Greene) Robinson. Northern Malvastrum. Fig. 3182. 



Malveopsis arcuata Greene, Man. Bay Reg. 66. 1894. 



Malvastrum arcuatum Robinson in A. Gray, Syn. Fl. N. Amer. 1^: 311. 1897. 

 Malacothamnus arcuatus Greene, Leaflets Bot. Obs. 1 : 208. 1906. 

 Sphaeralcea arcuata Arthur, Torreya 21: 11. 1921. 



Erect shrub 1-2.5 m. high, densely stellate-tomentose throughout, the hairs appressed, white 

 on stems and leaves, stramineous and slightly scurfy on the calyces. Leaves ovate, 1-4 on. 

 broad, 1.5-5 cm. long, obscurely 3-5-lobed, crenate, rugose, veiny and paler beneath; petioles 

 stout, '0. 5-2 cm. long; stipules lanceolate, 5-8 mm. long; inflorescence interrupted-spicate, some- 

 what' secund, flowers sessile ; involucellate bractlets linear-subulate, 5-8 mm. long, equaling or 

 surpassing the calyx-tube ; calyx obovate, 6-10 mm. long, densely stellate-pubescent ; calyx-lobes 

 ovate, acute to short-mucronate, 2-4 mm. long and broad; petals 15-20 mm. long, rose-colored; 

 stamineal column slender, about one-third to half as long as the petals, glabrous ; carpels reni- 

 form-ovate, about 3 mm. high, closely appressed-stellate-pubescent on the summit and about one- 

 third down the backs ; seeds dark brown, irregularly stellate-puberulent, surface minutely tessel- 

 lated. 



Occasional on hillsides and dry ravines, Upper Sonoran Zone; San Mateo County to southern Santa Clara 

 County, California. Type locality: eastern slopes of the Coast Range back of Belmont, San Mateo County. 

 May-Sept. 



7. Malvastrum nesioticum Robinson. Insular Malvastrum. Fig. 3183. 



Malvastrum nesioticum Robinson in A. Gray, Syn. Fl. N. Amer. 1^: 312. 1897. 



Malacothamnus nesioticus Abrams, Bull. N.Y. Bot. Gard. 6:419. 1910. 



Sphaeralcea nesiotica Jepson, Man. Fl. PI. Calif. 634. 192S. 



Sphaeralcea fasciculata var. nesiotica Jepson, Fl. Calif. 2: 501. 1936. 



Malvastrum fasciculatum var. nesioticum McMinn, 111. Man. Calif. Shrubs 348. 1939. 



A much-branched shrub 1-2 m. high, stems, inflorescence, and lower surfaces of the leaves 

 minutely but densely stellate-canescent. Leaves pentagonal, leathery, 3-5-lobed, cordate, 2-4.5 

 cm. long, green and glabrate above, densely fine-canescent beneath, irregularly crenate, margins 

 often revolute; petioles stout, 5-15 mm. long; stipules ovate, 2-3 mm. long; inflorescence a 

 rigid, ascending panicle, many-flowered; involucellate bractlets setaceous, 2-3 mm. long; calyx 

 campanulate, 5-8 mm. long, finely but densely stellate-canescent, the lobes broadly ovate, 2-3 

 mm. long, 3-5 mm. wide at the base, abruptly acute, veiny at maturity; petals rose-pink, 10-15 

 mm. long, slightly clawed; stamineal column about equaling the calyx-lobes; carpels oboyate- 

 reniform, 4 mm. high, stellate-puberulent on the summit ; seeds irregularly covered with minute 

 stellate puberulence. 



Dry slopes and small canyons. Upper Sonoran Zone; Santa Cruz Island, Santa Barbara County, California. 

 Type locality: "Island of Sta. Cruz.'' April-Aug. 



Malvastrum nesioticum subsp. Nuttallii (Abrams) Wiggins. (Malacothamnus Nuttallii Abrams, Bull. 

 NY. Bot. Gard. 6: 417. 1910; Sphaeralcea fasciculata var. Nuttallii Jepson, Fl. Calif. 2: 501. 1936.) Leaves 

 equally pubescent on both surfaces, not revolute; calyx-lobes glabrous on the inner surface except at the very 

 tip. Rocky hillsides and small gulches, Upper Sonoran Zone; Santa Barbara and Ventura Counties, California. 

 Type locality: Casitas Pass, Ventura County, California. 



8. Malvastrum Palmeri S. Wats. Palmer's Malvastrum. Fig. 3184. 



Malvastrum Palmeri S. Wats. Proc. Amer. Acad. 12:250. 1877. 

 Sphaeralcea Palmeri Jepson, Man. Fl. PI. Calif. 633. 1925. 



A stout leafy shrub 1-2.5 m. high, densely and coarsely stellate-tomentose throughout with 

 scurfy, tawny hairs. Leaves broadly ovate to pentagonal, 5-lobed, 2-6 cm. broad, 2.5-7 dm. long, 

 truncate to subcordate at the base, crenate-serrate, densely stellate-tomentose on both surfaces ; 

 petioles 1-3 cm. long; stipules ovate to lance-triangular, abruptly acuminate, 6-10 mm. long, 

 sparsely pubescent ; inflorescence of dense capitate terminal, usually solitary clusters, the flowers 

 sessile, subtended by ovate, entire or 3-lobed foliaceous bracts; involucellate bractlets ovate- 

 lanceolate, acuminate, equaling or exceeding the calyx-lobes; calyx densely stellate-pubescent, 

 the lobes ovate, acute or short-acuminate, 2^ mm. broad, 4-6 mm. long; petals obovate, emar- 

 ginate or rounded at the summit, 10-14 mm. long, rose-colored; carpels obovate-reniform, 3-3.5 

 mm. high, stellate-pubescent on the summit, glabrous on the backs and sides. 



Canyons and hillsides near the sea, Upper Sonoran Zone; in San Luis Obispo County, California. Type 

 locality: Cambria, a mile from the sea, San Luis Obispo County. April-Aug. 



Malvastrum Palmeri var. involucratum (Robinson) McMinn, 111. Man. Calif. Shrubs 339. 1939. (Mal- 

 vastrum involucratum Robinson in A. Gray, Syn. Fl. N. Amer. l^: 310. 1897.) Differs from M. Palmeri m 

 having leaves bright green and glabrate on the upper surface; entire, somewhat narrower bracts subtending the 

 flowers; and the heads of the inflorescence denser and frequently several subterminal clusters below the terminal 

 one. Hillsides and valleys in the Upper Sonoran Zone from Carmel Valley to Jolon, Monterey County, California. 

 Type locality: Jolon, Monterey County. 



9. Malvastrum aboriginum Robinson. Indian Valley Malvastrum . Fig. 3185. 



Malvastrum aboripinum Robinson in A. Gray, Syn. Fl. N. Amer. 1^: 311. 1897. 

 Sphaeralcea aboriginum Jepson, Fl. Calif. 2: 498. fig. 240. 1936. 



A Stout shrub 1-1.5 m. high, with densely stellate-tomentose foliage and branches. Leaves 

 ovate to orbicular, shallowly cordate and 3-5-lobed, irregularly dentate-crenate, 1 . 5-5 cm. long, 

 nearly as broad to slightly wider, densely pubescent on botH surfaces with short-rayed, tawny 

 stellate hairs; petioles 0.5-3 cm. long, stout; stipules lance-ovate, 4-6 mm. long; inflorescence 



