180 University of California Publications in Botany [VOL. 9 



5. CERASTIUM 



1. Cerastium arvense var. Sonnei (Greene), comb. nov. 



C. Sonnei Greene, Pitt., vol. 4, p. 303. 1901. 



Type locality. "From an altitude of 8,000 feet on Mt. Rose." 

 C. F. Sonne. 



Range. Sierra Nevada. 



Zone. Upper Transition and above. 



Specimen examined. Rosasco's, Tuolumne County, Chesnut and 

 Drew, June 25, 1889. 



This variety scarcely merits discrimination were it not for the fact 

 that in the higher mountains the familiar chickweed of the lowlands 

 (C. arvense L.) becomes conspicuously more viscid-glandular and 

 with shorter petals and capsules. By these characters the high country 

 plant approaches forms of C. alpinum L., especially C. alpinum var. 

 Beeringianum Regel (Bull. Soc. Nat. Mosc., vol. 35, p. 316). There is 

 preserved in the herbarium of the University of California a fragment 

 of a plant collected by Theo. Labouchere on Mt. Dana, July, 1915, 

 which is probably to be referred to the last named variety. The 

 specimen is, however, so small and immature, the capsule not evident, 

 that definite reference seems at present premature. The variety is 

 known to range from Alaska to New Mexico and Arizona. 



22. PORTULACACEAE (PURSLANE FAMILY) 



Stamens more than 5 (L. triphylla has 4-5 stamens but is recognized by the 



capsule with circumscissile dehiscence) 1. Lewisia 



Stamens 5 or fewer; capsule with valvular dehiscence. 

 Stamens 5; style deeply 3-divided. 



Stems from deep-seated globose corms 2. (/laytonia 



Stems from slender rootstocks ...3: Montia 



Stamens 3; style simple 4. Spraguea 



1. LEWISIA 



(All our forms are of the subgenus Oreobroma) 



Leaves all radical; root fusiform; plants without corms. 



Flowers red, numerous in divaricate panicles on impersistent scapes; leaves 



much shorter than the scapes 1. L. leana 



Flowers white on persistent recurving scapes (L. pygmaea sometimes has red 

 petals but its leaves always equal and usually exceed the 1- or 2-flowered 

 scapes). 



Sepals obtuse or truncate and glandular-denticulate 2. L. pygmaea 



Sepals acute, not glandular, and entire 3. L. nevadensis 



Cauline leaves opposite or whorled (2-5) ; stems from a small globose corm. 

 4. L. triphylla 



