MUSTARD FAMILY 77 



species from Delano, Kern Co. (Z>. Steinwand), the pods show considerable variation in com- 

 pression: they may be (a) compressed throughout, (b) compressed on lower half and obcom- 

 pressed on upper half, or (c) they may be somewhat contorted with the compression obscure. 

 Variation similar to this is often met with in T. gracile and is paralleled in T. capparideum 

 Greene. In a field near the Mountain House, eastern Alameda Co. (Jepson 15,349), two forms 

 of T. capparideum were found : first, plants of branching habit which bore the inflated-subcylin- 

 dric type of pod usual to T. capparideum, and also pods compressed below, sometimes obcom- 

 pressed above; second, strictly erect plants bearing only the type of pods characteristic of 

 typical T. capparideum. Prolonged consideration of T. capparideum seems convincing that it 

 is to be regarded as a sporting or reversionary form of T. gracile and not as a species in the sense 

 that T. gracile is a species. Its features are so remarkable, however, that we retain it here, for 

 the time, as a nominal species. 



Plants, when robust, with mostly straggling branches ; pods 2-valved and 2-celled 1. T. gracile. 



Plants commonly erect; pods 4-valved and 1-celled 2. T. capparideum. 



1. T. gracile Hook. Dobie Pod. Stems erect or at last very diffuse, 5 to 14 

 inches long; leaves pinnatifid, the segments commonly linear, acutish, cleft or 

 entire ; basal leaves 1 to 4 inches long, petioled ; cauline leaves more or less reduced, 

 subsessile or sessile; pedicels axillary, 3 to 10 lines long, spreading; stamens very 

 unequal; pods linear, strongly obcompressed throughout, tardily dehiscent, 1 to 

 1^ inches long; seeds in 2 rows. 



Valleys and hill slopes, 200 to 2200 feet : plains and low hills on the borders of 

 the Great Valley; South Coast Ranges; Inyo Co. and south through the Mohave 

 Desert to San Diego Co. Mar.-Apr. 



Field note. — In the vernal grassland formation Tropidocarpum gracile is a common species, 

 especially in the inner South Coast Eange region. While it is infrequent or absent from the more 

 sterile clays it is common on the intermediate clays and frequently it is one of the dominants. 

 On spots of very rich soil it sometimes develops colonies three to twelve feet across. Such colonies 

 are pure and represent a dense and very tangled growth. 



Locs. — Salt Creek, w. Tehama Co., Jepson 178c; Marysville Buttes, Jepson 13,491; Auburn, 

 comm. W. S. SliocTcley ; Eio Linda, n. Sacramento Co., Jepson 16,595; Salmon Falls, Eldorado 

 Co., Jepson 15,752; Kinsley, Mariposa Co., Charlotte Eoak; St. Helena, Clara Hunt; Corral 

 Hollow, Jepson 9567, 9573; Los Buellis Hills, Santa Clara Co., R. J. Smith; Stanford, C. F. 

 Baker 336 ; Guadalupe Mine, Santa Clara Co., Jepson 9087 ; Soledad ; Little Eabbit Valley, San 

 Benito Co., Jepson 16,134; Cholame Valley, se. Monterey Co., Jepson 16,183; Santa Margarita, 

 Jepson 11,970; Waltham Creek, San Carlos Eange, Jepson 2691; Madera, Jepson 15,156; Spark- 

 ville, Fresno Co., Jepson 15,141; Goshen; Tulare, Davy 3097; Three Elvers, W. Fry 150; Inde- 

 pendence, S. W. Austin 431; Searles, Mohave Desert; Granite Wells, Mohave Desert; Barstow; 

 Eedlands, Parish; San Jacinto, Gregory; San Felipe; San Diego, Cleveland. 



Var. dubium Jepson. Pod 1-celled below, the partition persistent in the upper third or 

 fourth; otherwise like the species. — West side of the San Joaquin Valley and south to coastal 

 Southern California. 



Eefs. — Teopidocabpum gracile Hook. Ic. PI. t. 43 (1836), type loc. "Monterey", Douglas; 

 Jepson, Fl. W. Mid. Mid. Cal. 223 (1901), ed. 2, 189 (1911), Man. 434 (1925). Var. scabrius- 

 culum Greene, Fl. Fr. 278 (1891). T. scahriusculum Hook. Ic. PI. t. 52 (1836), type loc. "Mon- 

 terey", Douglas. Var. dubium Jepson, Man. 434 (1925). T. duMurn Dav. Erythea 2 :179 (1894), 

 type loc. near Los Angeles, Davidson; Jepson, Fl. W. Mid. Cal. 223 (1901), ed. 2, 189 (1911). 

 In neither T. gracile nor T. scabriusculum is the locality "Monterey" recorded on the original 

 specimens in Herb, Hook. (Kew). See note under Thelypodium flavescens Wats. 



2. T. capparideum Greene. Alkali Pod. Stem stoutish, erect, 8 to 10 inches 

 high, simple or sparingly branched; foliage as in T. gracile, the upper leaves some- 

 what more deeply parted and with longer subentire segments; pods linear-oblong, 

 7 to 10 lines long, 2 lines wide, somewhat inflated, 1-celled, conspicuously 6-nerved, 

 tipped with a short style; valves 4, the dehiscence beginning at the apex; seeds in 

 4 rows. 



Alkaline soil, 25 to 500 feet : Mt. Diablo range and bordering plains. Mar. 



Locs.— Clayton, Davy 1262; Byron, Greene; Mountain House, e. Alameda Co., Jepson 15,349; 

 TrHiCV J^icllGTlGT S* SiolGfti 



Eefs.— Tropidocarpum capparideum Greene, Pitt. 1:217 (1888), type loc. eastern Contra 

 Costa Co. near the San Joaquin Eiver, Greene; Jepson, Fl. W. Mid. Cal. 223 (1901), ed. 2, 189 

 (1911), Man. 435 (1925). 



