VOL. II.] 



MUSTARD FAMILY. 



5. CORONOPUS Gaertn. Fruct. & Sem. 2: 293. 1791. 



Annual or biennial, diffuse herbs, with mostly pinnatifid leaves, and small whitish flow- 

 -ers. Silicles small, didymous, laterally compressed, sessile. Stamens often only 2 or 4. 

 Valves of the capsule oblong or subglobose, obtuse at each end, indehiscent, falling away 

 from the septum at maturity. Seeds i in each cell; cotyledons narrow, incumbent or con- 

 duplicate. [Greek, crow-foot, from the shape of the leaves.] 



About 6 species, of wide geographic distribution in warm and temperate regions. 



Pod rugose, not crested. 



Pod coarsely wrinkled, crested. 



i. Coronopus didymus (L-.) J. E. 



Smith. Lesser Wart-cress. 



(Fig. 1690.) 



Lepidium didymum'L,. Mant. 92. 1767. 

 .Senebiera didyma Pers. Syn. 2: 185. 1807. 

 Coronopus didymus J. E. Smith, Fl. Brit. 3: 691. 

 1800. 



Diffuse, tufted, spreading on the ground, spar- 

 ingly pubescent. Stems 2'-!$' long, branching; 

 leaves deeply i-2-pinnatifid, the lower slender- 

 petioled, the upper sessile; flowers minute, 

 white, racemose; pedicels slender, i // -i^ // 

 long in fruit; pod didymous, about i // broad 

 and slightly more than *4" high; valves rugose, 

 obtuse at each end and readily separating into 

 2 ovoid nutlets. 



In waste places, Newfoundland to Florida, Mis- 

 souri and Texas, west to California. Abundant in 

 ballast about the northern seaports. Also through- 

 out tropical America and widely distributed in the 

 Old World. Summer. Naturalized from the South. 



1. C. didymus. 



2. C. Coronopus. 



2. Coronopus Coronopus (I,.) Karst. 

 Wart or Swine's Cress. (Fig. 1691.) 



Cochlearia Coronopus I,. Sp. PI. 648. 1753. 



Senebiera Coronopus Poir. in Lam. Encycl. 7: 76. 1806. 



Coronopus Coronopus Karst. Deutch. Fl. 673. 1880-83. 



Diffuse, tufted, spreading on the ground, succulent, 

 glabrous and glaucous, or with a few spreading hairs, 

 branching. Stems 2 / -i5 / long; leaves similar to those of 

 the last species, generally larger, sometimes less divided; 

 flowers similar; pedicels stout, \" long or less; pod 2" 

 broad and about \y t " high, flattish, rounded, apiculate 

 at the summit, marked with coarse wrinkles which form 

 a crest around the margin; valves not distinctly separate. 



In. waste places and on ballast, New Brunswick to Florida 

 and the Gulf States. Fugitive or adventive from Europe. 

 Sometimes called Buckshorn and Herb Ivy. Summer. 



6. THLASPI L,. Sp. PL 645. 1753. 



Erect glabrous annual or perennial herbs, with entire or dentate leaves, the basal ones 

 forming a rosette, those of the stem, or at least the upper ones, auriculate and clasping. 

 Flowers white or purplish. Siliques obcuneate, obcordate, or oblong-orbicular, mostly emar- 

 ginate, flattened at right angles to the narrow septum, crested or winged. Valves dehiscent. 

 Seeds 2 or several in each cell, wingless. Cotyledons accumbent. [Greek, to flatten, from 

 the flat pod.] 



A genus of about 25 species, natives of temperate, arctic and alpine regions. In addition to the 

 following, 2 others occur in arctic America, the Rocky Mountains and California. 



Lower stem-leaves not clasping; seeds rugose. 

 All the stem-leaves cordate-clasping; seeds smooth. 



8 



1. T. arvense. 



2. T. perfoliatum. 



