Gen. Pl. 11: 876. 1839.
Biennials, perennials, or, rarely, annuals; not scapose; glabrous or pubescent. Stems (simple or few to several from base), usually erect, rarely decumbent, branched basally and/or distally, (glabrous or pubescent). Leaves basal and cauline; petiolate or sessile; basal rosulate or not, petiolate, blade margins usually entire, dentate, lyrate or pinnately lobed, rarely laciniate; cauline petiolate or sessile, blade (base cuneate, attenuate, auriculate, sagittate, or amplexicaul), margins often entire, sometimes dentate or pinnately lobed. Racemes (corymbose, dense or lax), usually slightly to considerably elongated in fruit (sometimes not elongated in T. integrifolium). Fruiting pedicels usually horizontal, erect to ascending, or divaricate, rarely reflexed, slender or stout, (flattened or not basally, glabrous). Flowers: sepals usually erect or ascending, rarely spreading to reflexed, ovate to oblong, linear, lanceolate, or oblanceolate, lateral pair slightly saccate or not basally; petals (erect or spreading), white, lavender, or purple, spatulate to obovate, or oblanceolate to linear, (margins crisped or not), claw differentiated or not from blade, (apex rounded); stamens subequal or tetradynamous, (exserted or included); filaments (erect or spreading, usually distinct, very rarely median ones united), not dilated basally; anthers usually linear to linear-oblong, rarely oblong or ovate, (sometimes apiculate, often circinately coiled after dehiscence); nectar glands confluent and subtending bases of stamens, or 2 or 4 and lateral. Fruits stipitate, linear, torulose or smooth, terete, slightly 4-angled, or flattened; valves each with prominent midvein, glabrous; replum rounded; septum complete; ovules 12–128 per ovary; style distinct, (often cylindrical, rarely subclavate or subconical); stigma capitate, entire. Seeds uniseriate, plump or flattened, not winged, usually oblong, rarely ovate; seed coat (minutely reticulate), not mucilaginous when wetted; cotyledons oblique, rarely incumbent or accumbent. x = 13.
w, wc North America, n Mexico.
Species 16 (16 in the flora).
As recognized herein and by recent authors (e.g., I. A. Al-Shehbaz 1973; R. C. Rollins 1993), Thelypodium is somewhat heterogeneous and the segregate Stanleyella might merit recognition, as by E. B. Payson (1923). Thelypodium has erect sepals, petals, and stamens, terete fruits, prominently veined fruit septa, and, often, cylindrical styles. In contrast, species of Stanleylla have spreading sepals, petals, and stamens, flattened fruits, veinless fruit septa, and clavate, subclavate, or subconical styles.
|1||Cauline leaves petiolate, (proximal blades: margins usually pinnately lobed, rarely dentate); petal claws widest at base||> 2|
|1||Cauline leaves sessile (blade bases often auriculate, sagittate, or amplexicaul, proximal blades: margins often entire); petal claws narrowest at base||> 7|
|2||Racemes dense; sepals erect; styles usually cylindrical, rarely subclavate in fruit||> 3|
|2||Racemes often lax; sepals spreading or ascending; styles usually clavate, subclavate, or subconical, rarely cylindrical in fruit||> 4|
|3||Stems solid; basal leaves: petioles glabrous; fruiting pedicels straight, horizontal; petals linear.||Thelypodium laciniatum|
|3||Stems hollow; basal leaves: petioles ciliate; fruiting pedicels strongly curved upward; petals spatulate to oblanceolate.||Thelypodium milleflorum|
|4||Stems hirsute or glabrous basally; fruits terete, submoniliform to strongly torulose (replum constricted between seeds).||Thelypodium laxiflorum|
|4||Stems glabrous basally; fruits flattened, torulose (replum not constricted between seeds)||> 5|
|5||Basal leaf blades usually ovate or obovate, rarely orbicular or spatulate, margins usually sinuate and repand, or dentate; petals lavender or purple, (2.5-)3-4 mm.||Thelypodium repandum|
|5||Basal leaf blades lanceolate, oblanceolate, or spatulate, margins mostly pinnately lobed; petals usually white, rarely lavender, (3.5-)4-7.5(-9) mm||> 6|
|6||Annuals; styles conical or subconical in fruit; petals spatulate; distalmost cauline leaf blade margins pinnately lobed (pectinate).||Thelypodium texanum|
|6||Biennials; styles clavate to subclavate in fruit; petals oblong to linear; distalmost cauline leaf blade margins usually entire or dentate, rarely lobed.||Thelypodium wrightii|
|7||Perennials, with (woody) caudex, covered with persistent petiolar remains; stems flexuous.||Thelypodium flexuosum|
|7||Biennials or perennials (short-lived), without caudex, not covered with persistent petiolar remains; stems straight||> 8|
|8||Cauline leaf blade bases cuneate to attenuate, not auriculate or sagittate.||Thelypodium integrifolium|
|8||Cauline leaf blade bases usually sagittate or amplexicaul, rarely auriculate||> 9|
|9||Terminal racemes often corymbose, not elongated in fruit||> 10|
|9||Terminal racemes not corymbose, considerably elongated in fruit||> 12|
|10||Basal leaves: petioles not ciliate, blade margins usually dentate to repand, rarely entire; cauline leaves erect (partly to completely appressed to stems); anthers exserted; fruits usually strongly incurved, overtopping buds.||Thelypodium rollinsii|
|10||Basal leaves: petioles ciliate, blade margins entire; cauline leaves ascending; anthers usually included; fruits often straight, not overtopping buds||> 11|
|11||Petals 2.5-5(-6) mm wide; fruits (0.8-)1.5-2.3 mm wide; seeds plump.||Thelypodium paniculatum|
|11||Petals (0.5-)1-3(-4) mm wide; fruits (0.5-)0.8-1(-1.2) mm wide; seeds flattened.||Thelypodium sagittatum|
|12||Racemes densely flowered; petal margins crisped throughout||> 13|
|12||Racemes lax; petal margins not crisped or crisped between blade and claw||> 14|
|13||Sepals lanceolate to linear-lanceolate or ovate; fruiting pedicels horizontal to divaricate, stout, base flattened, 1-2(-2.5) mm; seeds plump.||Thelypodium brachycarpum|
|13||Sepals oblong to linear-oblong; fruiting pedicels erect or erect-ascending (appressed to rachis at least basally), slender, base not flattened, (1.5-)2-5(-10) mm; seeds flattened.||Thelypodium crispum|
|14||Petals linear, 0.3-0.5(-0.8) mm wide; s California.||Thelypodium stenopetalum|
|14||Petals spatulate to oblanceolate, (0.5-)1-3(-4) mm wide; not s California||> 15|
|15||Flower buds oblong-linear; anthers exserted; gynophores (1-)2.5- 6 (-7.5) mm in fruit.||Thelypodium eucosmum|
|15||Flower buds ovate to lanceolate; anthers partially to wholly included; gynophores (0.2-)0.5-1(-3.5) mm in fruit||> 16|
|16||Fruiting pedicels ascending, straight; fruits forming straight line with pedicels; Oregon.||Thelypodium howellii|
|16||Fruiting pedicels horizontal to divaricate, often curved upward; fruits forming arc with pedicels; not Oregon.||Thelypodium sagittatum|