410 



ROSACEAE 



3. Physocarpus alternans (M. E. Jones) J. T. Howell. Nevada Ninebark. 



Fig. 2364. 



Neillia monogyna var. alternans M. E. Jones, Zoe 4: 42. 1893. 

 Opulaster alternans Heller, Cat. N. Amer. PI. ed. 2. 5. 1900. 

 Physocarpus alternans J. T. Howell, Proc. Calif. Acad. IV. 20: 130. 



1931. 



Densely branched shrub 5-15 dm. high, bark shreddy, tawny or grayish white, young 

 twigs stellate-pubescent. Leaves 5-18 mm. broad, suborbicular, cordate, 3-7-lobed, the lobes 

 doubly crenate, rather thinly short-pubescent with stellate hairs on both surfaces; petioles 

 and pedicels stellate-pubescent, 5-10 mm. long; corymbs 3-12-flowered ; hypanthium stellate 

 on the back, glabrous within, 3-4 mm. broad ; sepals ovate, 3 mm. long, stellate on the back, 

 less so within ; petals suborbicular, 3-4 mm. long ; stamens about 20, alternating ones longer 

 and with more dilated filaments ; follicle solitary, about 5 mm. long, densely stellate-pubescent. 



Rocky canyon slopes, Arid Transition and Canadian Zones; White Mountains, Inyo County, California, 

 eastward through central Nevada to the Wasatch Mountains, Utah. Type locality: Duck Creek, altitude 7,300 

 feet, Schell Creek Mountains, Nevada. June-Aug. 



Physocarpus alternans subsp. panamintensis J. T. Howell, op. cit. 132. Upper surfaces of the leaves 

 densely stellate-pubescent, instead of thinly so. Otherwise like the typical species. Panamint Mountains, Inyo 

 County, California. Type locality: on saddle between Johnson and Surprise Canyons, altitude 8,500 feet. 



Physocarpus alternans subsp. annulatus J. T. Howell, op. cit. 133. Essentially the same as the typical 

 species except for a ring of hairs near the top of the hypanthium on the inner surface. Described from plants 

 collected on Wyman Creek, altitude 8,500 feet, White Mountains, Inyo County, California. Plants collected in 

 Marble Canyon of Black Canyon in the same mountain range are without this hairy ring, so the character seems 

 to have little taxonomic significance. 



3. SPIRAEA L. Sp. PI. 489. 1753. 



Shrubs with simple usually serrate leaves without stipules, and corymbose, racemose 

 or paniculate inflorescence. Flowers perfect. Hypanthium campanulate or turbinate. 

 Sepals 5. Petals 5, white or rose-colored. Stamens 15-70, inserted in one to several series 

 under the margin of the disk. Pistils 3-8, usually 5; ovules 2 to several. Follicles not 

 inflated, opening along the ventral side. Seeds tapering at both ends, pendulous; endo- 

 sperm scanty or none. [Greek, meaning twisted, the follicles twisted in some species.] 



About 70 species, natives of the north temperate zone. Type species, Spiraea salicifolia L. 



Panicle flat-topped; sepals not reflexed. 



Petals rose-colored. 1. -S - - densi flora. 



Petals white. 2. S. lucida. 

 Panicles elongated; sepals soon reflexed. 



Leaves green and glabrous or nearly so beneath. 3. S. Mensiesii. 



Leaves white-tomentose beneath. 4. 5". Douglasii. 



1. Spiraea densifldra Nutt. Rose-colored Meadow-sweet. Fig. 2365. 



Spiraea densiflora Nutt. ex Torr. & Gray, Fl. N. Amer. 1: 414. 1840. 

 Spiraea Helleri Rydb. Fl. N. Amer. 22: 248. 1908. 



A low shrub with ascending branches, 2-6 dm. high, glabrous throughout or with a few 

 hairs on the leaf margins. Leaves oval or elliptical, rounded at both ends, 1.5-3 cm. long, 

 crenate or serrate above the middle ; inflorescence flat-topped or rounded, 2-4 cm. broad ; 







2366 



2367 



2368 



2366. Spiraea lucida 



2367. Spiraea Menziesii 



2368. Spiraea Douglasii 



