52 CRUCIFERAE 



387 (1911), Man. 424 (1925). Var. dolichocarpa Fer. Rhod. 11:140 (1909), typo loc. w. 

 Klickitat Co., Wash., Suksdorf 2022. B. vulgaris var. arcuata B. & W. Bot. Cal. 1:40 (1876). 



12. RADICULAIIill 



Nearly or quite jjlabrons herbs, soiiu'tiiiics j^rowinp; in Avater, mostly in wet 

 places. Leaves toothed or piniiatifid or pinnately divided. Flowers small, white 

 or yelloAV. Sepals spreading: in anthcsis. Petals scarcely clawed. Stigma capi- 

 tate, nearly sessile. Pod linear or oblong, terete or nearly so, valves mostly 

 1-nerved. Seeds minute, in 2 rows in each cell; cotyledons accumbent. — About 

 50 species, all continents but most abundant in the north temperate zone. (Dimin- 

 utive of Latin radix, radish. ) 



Flowers white; petals distinctly clawed, nearly twice the length of the sepals; perennial 



1. K. nasturtium-aquaticum. 

 Flowers yellow; petals scarcely clawed, shorter or little longer than the sepals. 

 Pods linear, more or less curved upward ; annual or biennial. 



Stems several from the base, diffuse ; leaves pinnately parted or divided, the lobes mostly 



regular and equal 2. B. curvisiliqua. 



Stem one, erect, branching above the base; leaves Ij'rately pinnatifid 3. E. palustris. 



Pods oblong, turgid, straight; low diffuse plants; perennial 4c. E. sinuata. 



1. R. nasturtium-aquaticum Britten & Rendle. Water Cress. Stems ascend- 

 ing or prostrate at base and rooting at the nodes; herbage glabrous; leaflets or 

 segments 3 to 9, ovate or nearly round, the terminal always the largest, or the 

 lowest leaves without lateral leaflets; flowers white, 2 to 2^) lines broad; petals 

 nearly twice the length of the sepals; pods divaricately spreading, I/2 to 1 inch 

 long, the pedicels % to as long. 



Abundant in slow-flowing creeks (especially where not bordered by trees) and 

 about springs in the mountains, 1 to 6000 feet: throughout California. Europe. 

 May-Aug. 



Immigration note. — While this plant has long been thought an introduced plant, it seems 

 not to be such in the most usual sense, that of involuntary introduction through modern trade and 

 traffic. There is developing a considerable body of evidence that Water Cress was present in 

 North America and in California before the advent of the historical settlements by Europeans. 

 This subject is well discussed by S. B. Parish in the Bulletin of the Southern California Academy 

 of Sciences (19': 18,— 1920). 



Locs. — Yreka, Butler 1056; Kneeland Prairie, Humboldt Co., Tracy 3830; Ulatis Creek, 

 nw. Solano Co., Jepson 13,401; Berkeley, Jepson; Dorrington, Calaveras Co., Jepson; Monterey 

 coast, Jepson; Cajon Pass, Peirson 372; Santa Ana, Alice King. 



K«fs. — Eadicxtla nasturtium-aquaticum Britt. & Rendle, Brit. Seed PI. 3:1907; Jepson, 

 Man. 424 (1925). Sisymbrium nasturtium-aquaticum L. Sp. PI. 657 (1753), type European; 

 Britt. & Br. 111. Fl. ed. 2, 2:162, fig. 2033 (1913). Nasturtium officinale R. Br.; Ait. Hort. Kew. 

 ed. 2,4:110 (1812); B. & W. Bot. Cal. 1:43 (1876); Jepson, Fl. W. Mid. Cal. 221 (1901), ed. 2, 

 187 (1911). Eoripa nasturtium Rusby, Mem. Torr. Club 3^:5 (1893). 



2. R. curvisiliqua Greene. Western Yellow Cress. Stems several to many 

 from the base, diffuse (rarely erect), 3 to 7 inches long (rarely to 1 or 1^/^ feet 

 long) ; herbage glabrous; leaves mostly % to 2 inches long, or the lowest or basal 

 often 3 to 12 inches long, their blades pinnatifid or pinnately parted (the seg- 

 ments varying from linear and commonly entire to oblong or ovate and either 

 entire, toothed or pinnatifid) ; pods linear, terete, more or less curved, 2i/2 to 7 

 lines long, the pedicels 14 to l^/^ lines long. 



Frequent in stream beds, margins of pools and marshy places, 10 to 7500 feet : 

 throughout California. North to British Columbia, east to Wyoming, south to 

 Lower California. Exceedingly variable in foliage. May- July. 



Locs. — Sierra Nevada: Hume Lake, Fresno Co., K. P. Kelley ; Hetch Hctchy, A. L. Grant 

 854; Belle Mdw., Tuolumne Co., Jepson 6488; Dorrington, Calaveras Co., Jepson 10,174; Blue 

 Canon, Placer Co., II. A. WalTcer 1208; Truckee, Sonne; PrattvUle, Plumas Co., Cleveland; Goose 

 Lake Valley, Modoc Co., R. M. Austin; Little Hot Springs Valley, Modoc Co., M. S. Baker; Still- 

 water, Shasta Co., M. S. Baker ; Medicine Lake, Siskiyou Co., M. S. Baker. Great Valley: Yuba 



