BRASSICACEAE 467 



lateral racemes. Sepals 4, spreading, equal. Corolla white to purple, the 4 petals larger 

 than the sepals. Stamens often 2 or 4. Ovary sessile : style wanting : stigma barely lobed. 

 Ovule usually solitary. Silicle laterally flattened, didymous, the valves crested, rugose or 

 coarsely wrinkled. Seed solitary. Cotyledons incumbent or conduplicate. [Senebiera 

 Poir.] WART CRESS. SWINE CRESS. 



Capsules finely wrinkled, crestless. 1. C. didymus. 



Capsules tuberculate- wrinkled, crested. 2. C. Coronopus. 



1. Coronopus didymus (L.) J. E. Smith. Sparingly pubescent. Branches ascend- 

 ing or prostrate, 1-4 dm. long : basal leaves 3-10 cm. long, with margined petioles and 1-2- 

 pinnatifid blades: stem-leaves similar to the basal but shorter and with much shorter 

 petioles, or sessile : racemes 1-5 cm. long : pedicels spreading, 1-2 mm. long : sepals ovate 

 to oblong-ovate, about 0.5 mm. long : petals white, less than twice as long as the sepals : 

 pods didymous, 2-2.5 mm. broad, notched, finely wrinkled. [Senebiera pinnatifida DC.] 



In waste places, Newfoundland to Missouri, California, Florida and Texas. Naturalized north- 

 ward. Spring and summer. 



2. Coronopus Coronopus (L. ) Karst. Fleshy, usually glabrous. Branches as- 

 cending or spreading, 0.5-3 dm. long : basal leaves 4-12 cm. long, with margined petioles 

 and pinnately-parted blades, the segments long and narrow : stem-leaves similar but smaller 

 and with shorter petioles : racemes 0.5-3 crn. long : pedicels 1-1.5 mm. long : sepals ob- 

 long or oval, nearly 1 mm. long : petals white, barely twice as long as the sepals : pods 

 not didymous, 3.5-4 mm. broad, apiculate, tuberculate-wrinkled. 



In waste places, New Brunswick to Florida and Texas. Also on the Pacific coast. Naturalized 

 from Europe. Spring to fall. 



2. BURSA Weber. 



Annual caulescent herbs, with glabrous or pubescent foliage. Leaves alternate, often 

 mainly basal : blades entire, lobed, or pinnatifid. Flowers perfect, in elongated racemes. 

 Sepals 4, spreading, equal. Corolla white, the petals much longer than the sepals. Ovary 

 sessile : style short : stigma capitate. Ovules numerous. Silicles strongly flattened con- 

 trary to the narrow septum, cuneate or obcordate, more or less deeply notched at the apex, 

 the valves boat-shaped. Seeds numerous in each cavity, marginless. Cotyledons accum- 

 bent. [ Capsella Medic. ] SHEPHERD'S PURSE. 



1. Bursa Bursa-pastoris (L.) Britton. Annual, more or less pubescent below, gla- 

 brous above. Stems 3-9 dm. tall, simple, or usually branching above : leaves mainly 

 basal ; petioles short ; blades pinnately lobed or pinnatifid, rarely dentate or entire, 3-15 

 cm. long : stem-leaves few, linear or lanceolate, auricled at the base : pedicels spreading 

 or ascending, 1-1.5 cm. long: sepals ovate or oval-oblong, about 1.5 mm. long: petals 

 white, spatulate, about twice as long as the sepals : pods triangular-cuneate or cuneate, 5- 

 8 mm. long, emarginate at the apex : seeds 10-12 in each cavity. 



In all situations, common nearly throughout North America. Naturalized from Europe and now 

 widely distributed over the globe. Spring to winter. 



3. LEPIDIUM L. 



Annual or biennial caulescent herbs. Leaves alternate : blades entire, lobed, incised 

 or pinnatifid, sometimes clasping the stem. Flowers perfect, in racemes or panicles. 

 Sepals 4, equal. Corollas white or greenish, the 4 petals small, or wanting. Stamens 

 usually fewer than 6. Ovary sessile : style slender, or wanting : stigma emarginate. 

 Ovule solitary, pendulous. Silicles oblong to orbicular, transversely flattened, sometimes 

 margined. Seed solitary in each cavity. Cotyledons incumbent or rarely accumbent. 

 PEPPERGRASS. 



Cotyledons accumbent. 1. L. Virginicum. 



Cotyledons incumbent. 



Capsules about 3 mm. broad : petals conspicuous. ' 2. L. medium. 



Capsules about 2 mm. broad : petals wanting or obsolete. 

 Pods as broad as long : pedicels glabrous or finely hirsute. 



Pedicels and pods glabrous. 3. L. apetalum. 



Pedicels and pods finely hirsute. 4. L. austrinum. 



Pods markedly longer than broad : pedicels puberulent. 5. L. interior. 



1. Lepidium Virginicum L. Annual or biennial, more or less puberulent. Stems 

 2-9 dm. tall, simple or widely branched : basal leaves spatulate or oblanceolate ; blades 

 pinnatifid, the segments toothed or incised, the terminal one much longer than the others ; 

 stem-leaves narrow, erect or ascending, sharply toothed or incised : pedicels finally spread- 



