MUSTARD FAMILY 299 



43. THYSANOCARPUS Hook. Fl. Bor. Amer. 1 : 69. pi. 18. f. A. 1833. 



Erect slender sparingly branched annuals, with minute white or rose-colored flowers 

 in slender elongated racemes. Sepals spreading, ovate. Petals spatulate. Stamens 6 or 

 rarely only 4. Ovary 1-celled, 1-ovuled. Silicle indehiscent, orbicular, strongly com- 

 pressed, winged, the wings entire, crenate or perforated, or with radiating nerves. [Name 

 from two Greek words, meaning fringe and fruit, in reference to the winged pod.] 



A genus of 3 or 4 species, natives of western North America. Type species, Thysanocarpus curvipes 

 Hook. 



Fruiting pedicels recurved their whole length; wings of the pods with broad radiating nerves or sometimes 

 nerveless. 



Basal leaves rosulate, usually hirsute; cauline lanceolate, auriculate. 1. T. curvipes. 

 Basal leaves not rosulate, usually glabrous, entire or sparingly laciniately toothed. 



Wings of the pod entire or crenate. 2. T. laciniatus. 



Wings of the pod divided into spatulate lobes, often revolute. 3. T. conchuliferus. 



Fruiting pedicels straight up to the abruptly recurved apex; wings of the pods with narrow almost filiform 



radiating nerves. 4 - T. radians. 



1. Thysanocarpus curvipes Hook. Hairy Fringe Pod. Fig. 2089. 



Thysanocarpus curvipes Hook. Fl. Bor. Amer. 1 : 69. pi. 18. f. A. 1833. 

 Thysanocarpus pulchellus Fisch. & Mey. Ind. Sem. Hort Petrop. 2: 50. 1835. 

 Thysanocarpus curvipes var. involutus Greene, Fl. Fran. 275. 1891. 



Plant more or less hirsute, the stems branching above, 2-5 dm. high. Basal leaves rosulate, 

 oblong in outline, pinnatifid with short blunt lobes or dentate; stem leaves lanceolate, sagittate, 

 auriculate-clasping, 1-2 cm. long; pedicels very slender, strongly recurved, 3-6 mm. long; pod 

 2-5 mm. in diameter, usually tomentose, wings entire or crenate, rarely perforated, often very 

 convex on one side; style very short, about 0.5 mm. long. 



Grassy hillsides, Upper Sonoran and Transition Zones; British Columbia and Idaho south to Lower Cali- 

 fornia. Type locality: "On moist ground near the Great Falls of the Columbia." 



This is a variable species and several segregates have been proposed. The following are the most pro- 

 nounced : 



Thysanocarpus curvipes var. longistylus Jepson, Man. Fl. PI. Calif. 447. 1925. Style slender, 1.25-2 

 mm. long, often slightly curved; pods as in the typical form. Arid Transition Zone, Sierra Nevada, California. 



Thysanocarpus curvipes var. elegans (Fisch. & Mey.) Robinson in A. Gray, Syn. Fl. N. Amer. I 1 : 

 114. 1895. Extremes readily distinguished from the typical species in the larger (5-7 mm. broad) perforated 

 pods; style exserted beyond the broad wing, 1-1.25 mm. long, but these characters are variable as is also the 

 pubescence of the pod. Grassy slopes, Upper Sonoran Zone; central California. 



2. Thysanocarpus laciniatus Nutt. Narrow-leaved Fringe Pod. Fig. 2090. 



Thysanocarpus laciniatus Nutt. ex Torr. & Gray, Fl. N. Amer. 1: 118. 1838. 



Plants smooth or nearly so and glaucous, the stems 2-4 dm. high, branching above. Leaves 

 not rosulate at base, the lower linear, subentire or pinnatifid into narrow linear acute segments ; 

 upper leaves narrowly linear, 2-3 cm. long and only 2-3 mm. wide, narrowed at base, and not 

 auriculate or obscurely so; pod elliptical to orbicular, 3-4 mm. in diameter, wing entire or 

 crenate, not perforated, reticulate, the body usually glabrous; pedicels slender, deflexed. 



Grassy plains and hillsides, Upper Sonoran Zone; Inner Coast Ranges of central California to Lower 

 California and Arizona. Type locality: Santa Barbara, California. March-April. 



Thysanocarpus laciniatus var. crenatus (Nutt.) Brewer in Brewer & Wats. Bot. Calif. 1: 49. 1880. 

 General habit of the typical species, but the stem usually a little stouter and more strictly erect ; pods usually 

 glabrous with the broad wings crenate and more or less perforated between the conspicuous radiating nerves. 

 Monterey County south to Santa Barbara, California. 



Thysanocarpus laciniatus var. emarginatus (Greene) Jepson, Man. Fl. PI. Calif. 447. 1925. Lower 

 part of stem hirsute; pods orbicular; glabrous wings entire or crenate, scarious, the radiating nerves wanting 

 or very short. California Coast Ranges from Contra Costa County to San Diego County. 



Thysanocarpus laciniatus subsp. desertorum (Heller) Abrams. (T. desertorum Heller, Muhlenbergia 2: 

 47. 1905.) Herbage glabrous and very glaucous; leaves rather thick and usually bluntly acutish; pods gla- 

 brous or often minutely scabrous, orbicular; wing scarious, entire, crenate or lobed, radiating nerves absent 

 or very short. Desert slopes from Inyo County, California, to Lower California. 



3. Thysanocarpus conchuliferus Greene. Island Fringe Pod. Fig. 2091. 



Thysanocarpus conchuliferus Greene, Bull. Torrey Club 13: 218. 1886. 

 Thysanocarpus laciniatus var. conchuliferus Jepson, Man. Fl. PI. Calif. 447. 1925. 



Plants simple or divergently branching, glabrous, 1-2 dm. high. Leaves linear, not rosulate 

 at base, the lower cleft into a few spreading lobes narrowed to the base, the upper auriculate- 

 clasping, toothed or entire ; racemes short ; flowers white or tinged with rose ; pods cymbiform, 

 the margin divided into spatulate lobes, strongly revolute; pedicels slender, diverging or some- 

 what recurved. 



Crevices of rocks or on mossy banks, Upper Sonoran Zone; Santa Cruz Island, southern California. 

 March-April. 



4. Thysanocarpus radians Benth. Ribbed Fringe Pod. Fig. 2092. 



Thysanocarpus radians Benth. PI. Hartw. 297. 1848. 



Plants glabrous, the stems 2-4 dm. high, with a few elongated ascending branches. Lowest 

 leaves runcinately toothed or pinnatifid, the upper ovate-oblong or ovate-lanceolate, subentire, 



