Capsella

Annuals or biennials; not scapose; mostly pubescent, trichomes sessile and stellate, sometimes mixed with simple or forked ones. Stems erect or ascending, unbranched or branched. Leaves basal and cauline; petiolate or sessile; basal rosulate, petiolate, blade margins pinnately lobed, lyrate, runcinate, or, rarely, entire, dentate, or repand [sinuate]; cauline blade (base sagittate, amplexicaul, or auriculate), margins entire, dentate, or sinuate. Racemes (corymbose, several-flowered), considerably elongated in fruit. Fruiting pedicels divaricate, slender. Flowers: sepals erect or ascending, [ovate-]oblong, (glabrous or pubescent); petals [sometimes absent] usually white or pink [reddish], obovate [spatulate], (much longer or shorter than sepals), claw differentiated from blade, (apex obtuse); stamens tetradynamous; filaments not dilated basally; anthers ovate [oblong], (apex obtuse); nectar glands (4), lateral, 1 on each side of lateral stamen. Fruits silicles, dehiscent, sessile, obdeltoid to obdeltoid-obcordiform, strongly flattened, strongly keeled, angustiseptate; valves (papery), each prominently veined, glabrous; replum rounded; septum complete; ovules (12–)20–40 per ovary; (style included or exserted from apical notch); stigma capitate. Seeds uniseriate, plump, not winged, oblong; seed coat (reticulate), mucilaginous when wetted; cotyledons incumbent. x = 8.

Distribution

Introduced; Europe, Asia, n Africa, introduced also in Mexico, West Indies, Central America, South America, Atlantic Islands, Pacific Islands, Australia.

Discussion

Species 4 (1 in the flora).

The number of species to be recognized in Capsella is controversial, and some authors (e.g., S. Svensson 1983; R. C. Rollins 1993; O. Appel and I. A. Al-Shehbaz 2003) treated the genus as monotypic, whereas others (e.g., H. Hurka and B. Neuffer 1997; P. Nutt et al. 2003) recognized three or four species.