14 POLYGONACEAE 



28. Chorizanthe rigida (Torr.) Torr. & Gray. 

 Rigid Chorizanthe or Spiny-herb. Fig. 1332. 



Acanthogonum rigidum Torr. Pacif. R. Rep. 4: 133. 1856. 

 Chorizanthe rigida Torr. & Gray, Proc. Araer. Acad. 8: 198. 1870. 



Stems erect, simple below, usually with a few short branches above, 3-8 cm. high, woolly- 

 tomentose. Leaves of the main stem alternate, the blades ovate to broadly obovate, 1-3 cm. long, 

 exceeded by the slender petioles, woolly-tomentose beneath, glabrous above, bearing 1 to several 

 short flowering branches in the axils, these densely clothed by subulate spinose bracts becoming 

 indurate and forming a dense thorny mass in age; involucres in clusters in the axils of the 

 bracts, the tube 2 mm. long, acutely 3-angled, prominently reticulate between the angles, teeth 3, 

 lanceolate, spreading, straight or spine-tipped, unequal, 4-15 mm. long; calyx-lobes oblong, 

 pubescent, yellow; stamens 9. 



Rocky ridges, Lower Sonoran Zone; Inyo County south through the Mojave and Colorado Deserts, Cali- 

 fornia to northern Lower California east to southern Nevada, western Arizona, and Sonora. Type locality: Un 

 William's River [Arizona], a fork of the Colorado." March-June. 



29. Chorizanthe Watsonii Torr. & Gray. 

 Watson's Chorizanthe or Spiny-herb. Fig. 1333. 



Chorizanthe Watsonii Torr. & Gray, Proc. Amer. Acad. 8: 199. 1870. 



Stems erect or ascending, 5-10 cm. high, well-branched, appressed villous-tomentose and 

 sometimes reddish. Leaves oblanceolate, 2-3 cm. long including the petiole, tomentose below, 

 appressed-vihous above ; lower bracts similar to the basal leaves but narrower, the upper acicular ; 

 involucres solitary or sometimes 2 or 3 in the axils of the cyme, cylindric, 3-4 mm. long, appressed- 

 pubescent, 5-toothed, four of the teeth short, recurved, uncinate, the anterior one much larger, 

 broadly lanceolate; calyx 3-4 mm. long, yellow, sparingly pubescent on the cylindric tube, the 

 lobes oblong, acute; stamens 9. 



Dry ridges and slopes, Upper and Lower Sonoran Zones; southeastern Washington and southwestern Idaho 

 south, east of the Cascade-Sierra Nevada Divide, to the Colorado Desert, California, and western Arizona. Type 

 locality: dry washes of the foothills from the Humboldt to Reese River, Nevada. April-June. 



30. Chorizanthe corrugata (Torr.) Torr. & Gray. 

 Wrinkled Chorizanthe or Spine-flower. Fig. 1334. 



Acanthogonum corrugatum Torr. Pacif. R. Rep. 5: 364. 18S6. 

 Chorizanthe corrugata Torr. & Gray, Proc. Amer. Acad. 8: 198. 1870. 



Stems erect, 5-15 cm. high, becoming much branched above, villous-tomentose. Leaves basal, 

 slender-petioled, the blades orbicular, 1-2 cm. broad, woolly-tomentose beneath, villous above; 

 bracts opposite, the lower foliaceous, spatulate, the upper reduced and acicular; involucres soli- 

 tary in the axils and loosely scattered in the lower forks, densely crowded above; the tube 

 cylindric, 2-5 mm. long, conspicuously transversely corrugated, 3-toothed, the teeth lanceolate, 

 equaling or exceeding the tube, spreading, the short spinose tip recurved not uncinate; calyx- 

 lobes oblong, obtuse; stamens 6; achene papulose at apex. 



Sandy washes and fiats, Lower Sonoran Zone; Death Valley region, California, to northern Lower California 

 and western Arizona. Type locality: near Fort Yuma, Arizona. March-May. 



31. Chorizanthe Vortriedei Brandg. 

 Vortriede's Chorizanthe or Spine-flower. Fig. 1335. 



Chorizanthe Vortriedei Brandg. Zoe 4: 158. 1893. 



Centrostegia Vortriedei Goodman, Ann. Mo. Bot. Gard. 21: 91. 1934. 



Stems low, spreading, trichotomously branched at the first node, dichotomous above, 6-15 cm. 

 long, sparsely and inconspicuously glandular. Leaves basal, spatulate, 1-2 cm. long, glabrous; 

 bracts small, deeply 3-lobed, the lobes triangular-lanceolate; involucres solitary at the rather 

 distant nodes, the tube 4-angled, 4-toothed, the teeth triangular-ovate, little spreading, cuspidate ; 

 flowers 2, on slender pedicels; calyx yellowish, 5-parted, the lobes 2-cleft and white at apex; 

 stamens 9. 



Dry gravelly or sandy soils, Upper Sonoran Zone; Santa Lucia Mountains, Monterey County, California. 

 Type locality: Santa Lucia Mountains, California. June— Sept. 



32. Chorizanthe insignis Curran. 

 Indian Valley Chorizanthe or Spine-flower. Fig. 1336. 



Chorizanthe insignis Curran, Bull. Calif. Acad. 1 : 275. 1885. 

 Oxytheca insignis Goodman, Ann. Mo. Bot. Gard. 21: 91. 1934. 



Stem erect, simple below, dichotomous with divergent branches above, 5-10 cm. high, glandu- 

 lar-puberulent. Leaves basal, narrowly spatulate, 8-15 mm. long, glabrous ; bracts 3-lobed ; lobes 

 lanceolate, 3-4 mm. long, the upper subulate-acicular ; involucres solitary at the nodes, very short- 

 peduncled, glandular, the tube prismatic-cylindric, 3-4 mm. long, slightly corrugated; teeth 5, 

 acicular, divergent, straight, about 3 mm. long; flowers 4-6, pedicelledj calyx rose-colored, 

 pubescent, the lobes oblong ; stamens 9. 



Sandy soils, Sonoran Zones; Inner Coast Ranges, Monterey and San Luis Obispo Counties, California. Type 

 locality: "Indian Valley near the Salinas River," near the boundary of Monterey and San Luis Obispo Counties. 

 June— Sept. 



