CHICKWEED FAMILY 147 



4. Arenaria pusilla S. Wats. Dwarf Sandwort. Fig. 1684. 



Arenaria pusilla S. Wats. Proc. Amer. Acad. 17: 367. 1882. 

 Alsinopsis pusilla Rydb. Bull. Torrey Club 39: 316. 1912. 

 Minuartia pusilla Mattf. Bot. Jahrb. 57. Beibl. 126: 28. 1921. 



A very diminutive glabrous annual, usually much branched from the base, the branches filiform, 

 2.5-5 cm. high. Leaves linear-subulate, 2-4 mm. long, obtuse and somewhat fleshy; sepals nar- 

 rowly lanceolate, acuminate or acute, 2-3 mm. long, nerveless or obscurely 1 -nerved; petals 1-2 

 mm. long, or none ; capsule equaling the sepals ; seeds smooth. 



Sandy soils, Upper Sonoran and Arid Transition Zones; Whitman County, eastern Washington, to Siskiyou 

 County, California. Type locality : Yreka, California. April-May. 



5. Arenaria tenella Nutt. Slender Sandwort. Fig. 1685. 



Arenaria tenella Nutt. in Torr. & Gray, Fl. N. Amer. 1: 179. 1838. 

 Greniera tenella Gay, Ann. Sci. Nat. III. 4: 27. 1845. 

 Alsine tenella Torr. Bot. Wilkes Exp. 243. 1874. 

 Alsinopsis tenella Heller, Muhlenbergia 8: 96. 1912. 

 Minuartia tenella Mattf. Bot. Jahrb. 57. Beibl. 126: 29. 1921. 



Slender annual, the stems usually simple below, dichotomously branched above, 8-25 cm. high, 

 glandular-pubescent. Leaves subulate, 5-15 mm. long, prominently ribbed, the upper reduced; 

 pedicels filiform; sepals lanceolate, 2.5-3 mm. long, prominently 3-nerved; petals oblong, equal- 

 ing or exceeding the sepals ; capsule exceeding the sepals, ovoid ; seeds with a finely muriculate 

 crest. 



Dry soils in open grasslands, Humid Transition Zone; British Columbia to northwestern Oregon. Type 

 locality: "Rocky places, plains of the Oregon." May-July. 



6. Arenaria paludicola Robinson. Swamp Sandwort. Fig. 1686. 



Arenaria paludicola Robinson, Proc. Amer. Acad. 29: 298. 1894. 



Alsine palustris Kell. Proc. Calif. Acad. 3: 61. 1863. 



Arenaria palustris S. Wats. Bot. Calif. 1 : 70. 1876. Not Gay, 1845. 



A palustrine glabrous perennial, the stems usually simple, elongated, weak and flaccid, con- 

 spicuously sulcate, procumbent and rooting at the nodes, leafy throughout. Leaves linear- 

 lanceolate, 1-3 cm. long, 2-6 mm. wide, sparingly scabrous on the margins ; pedicels solitary in 

 the axils, 2-4 cm. long ; sepals 3 mm. long, ovate-lanceolate, acute, nerveless ; petals oblong- 

 obovate, 5-6 mm. long. 



Swamps, Transition and Upper Sonoran Zones; near Tacoma, Washington, and San Francisco, Santa Barbara, 

 and Los Angeles, California. Possibly more generally distributed but rarely collected. Type locality: San Fran- 

 cisco. May-Aug. 



7. Arenaria Nuttallii Pax. NuttaU's Sandwort. Fig. 1687. 



Arenaria pungens Nutt. ex Torr. & Gray, Fl. N. Amer. 1 : 179. 1838. 

 Arenaria Nuttallii Pax, Bot. Jahrb. 18: 30. 1893. 

 Alsinopsis occidentalis Heller, Muhlenbergia 8: 96. 1912. 



Stems many from a perennial taproot, loosely matted, ascending or decumbent, 6-12 cm. long, 

 glandular-villous throughout. Leaves subulate, 6-10 mm. long, crowded, pungent, ascending or 

 commonly recurved-spreading ; cymes few- to many-flowered; pedicels 5-15 mm. long; sepals 

 lanceolate, 4-5 mm. long, acuminate ; petals shorter than the sepals, oblong-linear ; capsule ovoid, 

 shorter than the sepals. 



Dry alpine ridges, Boreal Zones; British Columbia to northern California, Montana, Wyoming, and Nevada. 

 Type locality: "Summit of hills in the Rocky Mountain range (lat. 41)." June— Aug. In the Pacific States the 

 typical or Rocky Mountain form of the species is mainly in eastern Oregon where we have specimens from 

 Wallowa, Warner and Steens Mountains. The Cascade Mountains plants of Washington and Oregon are some- 

 what intermediate between this and the following varieties. 



Arenaria Nuttallii var. gregaria (Heller) Jepson, Fl. Calif. 492. 1914. {A. gregaria Heller, Bull. S. 



Calif. Acad. 2: 67. 1903.) Plants more densely glandular-villous and cinereous; leaves shorter, rather blunt 



and not pungent; petals as long as or longer than the sepals, broader. Siskiyou Mountains and North Coast 

 Ranges to Mount Senhedrin, Lake County, California. 



Arenaria Nuttallii var. gracilis (A. Gray) Robinson, Proc. Amer. Acad. 29: 30. 1894. {A. pungens yar. 

 gracilis A. Gray.) Less glandular-villous; leaves narrowly subulate with an attenuate pungent tip, ascending, 

 rarely spreading; flowers solitary or in few-flowered cymes; petals shorter than the sepals. High altitudes of the 

 central Sierra Nevada to the San Bernardino Mountains, California. 



8. Arenaria propinqua Richards. Boreal Sandwort. Fig. 1688. 



Arenaria propinqua Richards, in Frankl. 1st Journ. Bot. App. 738. 1823. 

 Arenaria verna var. hirta S. Wats. Bot. King Expl. 41. 1871. 

 Alsinopsis propinqua Rydb. Bull. Torrey Club 33: 140. 1906. 

 Arenaria verna var. propinqua Fernald, Rhodora 8: 32. 1906. 

 Arenaria verna var. pubescens Fernald, Rhodora 21 : 21. 1919. 



Plants densely glandular-puberulent, the stems arising from a slender taproot, branched from 

 the base and more or less tufted, 3-10 cm. high. Leaves linear-subulate, flat and strongly 3-nerved, 

 3-10 mm. long, ascending, pungent ; flowers in open cymes ; sepals lanceolate, 3 mm. long, 

 3-nerved; petals about 4 mm. long ; capsule a little shorter than the sepals. 



Rocky or sandy soils, Boreal Zones; British Columbia and the Hudson Bay to Siskiyou Mountains, California, 

 and New Mexico. Type locality: northern Canada. June-Aug. 



