BUTTERCUP FAMILY 531 



Greene l.c., type loc. Witch Creek, San Diego Co., Alderson. Var. CAESIUM Jepson. T. caesium 

 Greene, Fl. Fr. 309 (1892), type loe. Sierra foothills, Greene; cf. K. Brandegee, Zoe, 4:81 

 (1893). 



5. T. occidentale Gray. Leaflets 1 to 2 inches long ; achenes few, lanceolate 

 or oblong-lanceolate, acuminate, scarcely oblique, 3 to 4 lines long, % to 1 line 

 wide, the sides with 3 prominent ribs or nerves. 



Moist shady places, extreme northern California. North to British Columbia, 

 thence east to the Atlantic. Rare with us. 



Locs. Plumas Co. (ace. Syn. Fl. I 1 : 16); Wooley Creek, w. Siskiyou Co., Butler 359. 

 Kef. THALICTRUM OCCIDENTALE Gray, Proc. Arn. Acad. 8:372 (1872), type from Ore., 

 E. Hall. 



12. MYOSURUS L. 



Dwarf annuals with entire tufted basal leaves and naked 1-flowered scapes. 

 Flowers whitish or yellowish, small (li/o to 2 lines broad). Sepals 5, spurred 

 at base. Petals 5, with a nectar-bearing hollow at the summit of the slender claw, 

 Stamens 5 to 20. Achenes numerous, crowded on a long and slender spike- 

 like receptacle. Ovules attached near the summit of the cell. Species 7, all 

 continents. (Greek mus, a mouse, and oura, a tail, in allusion to the curious 

 receptacles.) 

 Flowers raised on scapes; achenes with an appressed beak. 



Back of aehene narrow, its keel ending in a straight or spreading subulate beak 



1. M. aristatus. 

 Back of achene rhomboidal, flattish, its low keel ending in a short or nearly obsolete 



beak 2. M. minimus. 



Flowers sessile in a close cluster on the ground, or shortly scapose; achenes with a spreading 

 beak 3. M, alopecuroides. 



1. M. aristatus Benth. Scapes several, % to 1% inches high ; leaves mostly 

 shorter than the scapes ; petals present or wanting ; spike-like receptacles 2 to 4 

 lines long; achenes thin- walled, the narrow back continued into a subulate 

 straightish or spreading beak. 



Mountains of the western United States. Occurring in extreme northern 

 California; also in Bear Valley, San Bernardino Mts. (ace. Parish). 



Var. lepturus Jepson n, comb. More slender, 1 to 3 inches high; carpels beakless or very 

 short-pointed; carpel-spike 3 to 8 lines long. Range of the species: Livermore and Sacra- 

 mento valleys (ace. Greene, Fl. Fr. 296). 



Eefs. MYOSURUS ARISTATUS Benth. in Hook. Lond. Jour. Bot. 6:458 (1847), type loc. 

 Camas Prairie, Coeur d'Alene, Ida., Gejrer 332; (cf. a paper by Tidestrom on this species, 

 Torreya 16:228-230, fig. 1, 1916). M. apetalus of N. Am. authors, not of Gay; Parish, 

 Zoe 4:161 (1893). Var. LEPTURUS Jepson. M. apctalus var. lepturus Gray, Bull. Torr. Club 

 13:2 (1886), based on spins, from n. Gal., Lemmon, and Ore., Howell. 



2. M. minimus L. MOUSE TAIL. Scapes 2 to 6 inches high, the slender 

 spike-like receptacles % to 1%, commonly about 1 inch long; leaves linear- 

 filiform, 1 to 2 inches long ; mature achenes with somewhat rhomboidal back and 

 very low keel ending in a straight appressed or rarely obsolete tip. 



Low ground : inner Coast Ranges ; Sacramento and San Joaquin valleys ; far 

 eastward. Back of achene broader than in the preceding. 



Locs. Tulare, Davy 3083; Mt. Eden, Alameda Co., K. Brandegee; lower San Joaquin, 

 Bioletti; Vacaville, Greene; Haas Slough, Solano Co., Jepson; Dixie Mts., Lassen Co., M. S. 

 Baker; Modoc Co., E. M. Austin. The plant from Livermore Valley (Greene), cited by Huth 

 as the type of M. breviscarpus var. calif ornicus Huth in Engler, Bot. Jahrb. 16:285 (1893) 

 probably should be listed here. 



Var. apus Greene. Spike-like receptacles nearly or quite sessile in a cluster amongst and 

 shorter than the leaves. Lower San Joaquin Valley; San Diego Co.; Lower California. This 

 variety is referred to M. sessilis Wats, (type loc. Umatilla Co., Ore.) by Huth (Engler, Bot. 

 Jahrb. 16:285, 1893). We have seen no specimens of M. sessilis from Oregon. 



Var. filif ormis Greene. Scapes 1 to 6 inches high ; receptacles not tapering, very slender, 

 almost thread-like. San Francisco and Antioch, ace. Greene. 



