312 LEGUMINOSAE 



rare in Solano Co. and is soUloni found again in anything like its former luxuriance or robustness. 

 The var. colunibinura is to be regarded as an exactly parallel mutant, since it developed under 

 the same conditions in the same locality. Morphologically viewed these two forms represent 

 extreme variations in the T. albopurpureum group. It is possible to present a long series 

 of specimens of T. albopurpureum with increasing size of heads ending in T. olivaceum and 

 another similar series ending in var. columbinum. The banner of T. olivaceum is oblong, with 

 the apex irregularly denticulate; the oblong brown seeds are faintly mottled. The banner of 

 var. columbinum is ovate-oblong, dilated at base ; the oval broAvn seeds are unmottled. 



Locs. — Anderson, Shasta Co., Alice King; Penryn, Placer Co., Curran; Willows, Glenn Co., 

 Jepson 13,657; Vacaville, Jepson 13,660; Sweeney Creek, nw. Solano Co., Jepson 8249. 



Var. columbinum Jepson. Dove Clover. Heads dove-color, longer than broad, 6 to 12 

 lines high; flowers similar to those of the species; pods pubescent, 1-seeded. — Sacramento Valley: 

 Vacaville, Jepson 13,656 ; Sweeney Creek, nw. Solano Co., Jepson 8251 ; College City, Colusa Co., 

 Alice King, 



Var. griseum Jepson. Heads gray, broadly ovate, 6 to 8 lines high ; corollas less completely 

 concealed. — San Carlos Range. 



Refs. — Trifolium olivaceum Greene, Pitt. 1:4 (1887), type loc. Vacaville, Solano Co., 

 Greene; McDer. N. Am. Sp. Trifolium 213, pi. 85 (1910) ; Jepson, PL W. Mid. Cal. ed. 2, 227 

 (1911), Man. 546, fig. 536 (1925). T. columbinum var. olivaceum Jepson, Fl. W. Mid. Cal. 307 

 (1901). Var. columbinum Jepson, Man. I.e. T. cohimbinum Greene, I.e., type loc. Vacaville, 

 Solano Co., Greene; Jepson, Fl. W. Mid. Cal. 306 (1901). T. olivaceum f. columhinum McDer. 

 I.e., pi. 86; Jepson, Fl. W. Mid. Cal. ed. 2, 228 (1911). Var. griseum Jepson, Man. I.e., type loc. 

 New Idria, San Benito Co., Jepson 2708. 



17. LOTUS L. Bird's-foot Trefoil 



Herbs or suffrutescent plants. Leaves alternate, pinnately compound, with 

 3 to many leaflets; stipules foliaeeous, searious, or gland-like. Flowers solitary or 

 umbellate, mostly leafy-bracteate. Calyx-teeth subequal. Corolla yellow to white, 

 often marked with rose, red or purple. Stamens diadelphous. Pod flattened or 

 terete, straight to strongly arcuate, one to many-seeded, dehiscent or indehiscent. — 

 Species 110 to 155, all continents; best represented in the northern hemisphere. 

 (Ancient Greek plant-name.) 



Bibliog. — Bentham, Geo., Observations on the genus Hosaekia and the American Loti (Trans. 

 Linn. Soc. 17:363-368, — 1835). Gray, A., Synopsis of the species of Hosaekia (Proc. Acad. 

 Phila. 15:346-352,-1863). Greene, E. L., Enumeration of N. Am. Loti (Pitt. 2:133-150,— 

 1890). Ottley, A. M., A revision of the California species of Lotus (Univ. Cal. Publ. Bot. 10:189- 

 305, pis. 61-82, — 1923) ; [the genus Lotus in] Jepson, Man. 547-556,-1925. 



A. Stipules foliaeeous or searious; flowers several to many in long-peduncled umbels; pods 



dehiscent, straight, not beaked or only abruptly and shortly so, 



remaining erect (Subgenus Hosackia). 



Bract usually distant from the umbel ; pedicels V2 to 5 lines long. 



Herbage densely white-velvety ; corolla-banner reddish, mngs white ; n. Sierra Nevada 



1. L. incanus. 

 Herbage not velvety. 



Herbage (in mature plant) glabrous or subglabrous. 



Corolla greenish-yellow; umbels mostly one-sided; leaflets thickish 



2. L. crassifolius. 



Corolla Avhite, the banner red; umbels not one-sided; leaflets thinnish 



3. L. aioriginus. 

 Herbage short-villous, often viscid-glandular ; corolla-banner red, keel and wings white ; 



leaflets thinnish 4. L. stipularis. 



Bract borne at base of umbel or none ; pedicels about % line long. 



Herbage glabrous; stems arising from a thickened root-crown; claws of petals well exserted 

 from calyx-tube. 



Bracts foliaeeous; corolla-banner yellow, the wings rose or lUac; Coast Ranges 



5. L. formosissimus. 

 Bracts usually reduced to a searious involucre; corolla-banner and keel yellow, the mngs 



white; n. Sierra Nevada 6. L. pinnatus. 



Herbage appressed-pubeseent ; stems arising from a slender branched rootstock; claws of 

 petals scarcely or obscurely exserted from calyx-tube 7. L. oblongifolius. 



