COELOPHRAGMUS O. E. Schulz in Engler, Pflanzenreich IV. 105(Heft 86): 157. 1924.
Ihsan A. Al-Shehbaz
Tribe: Thelypodieae Prantl in Engler & Prantl, Nat. Pflanzenfam. III. 2: 155. 1891.
Name derivation: from Greek kilos (Latin coelus), hollow, and phragmos, partition (septum), in reference to invaginations on both sides of the fruit septum where the seeds are located.
Type species: C. auriculatus (A. Gray) O. E. Schulz (based on Sisymbrium auriculatum A. Gary).
Herbs, annual. Trichomes simple. Multicellular glands absent. Stems erect to ascending, simple, branched above. Basal leaves petiolate, not rosulate, simple, pinnatifid or runcinate with dentate or entire lobes; cauline leaves petiolate, auriculate or amplexicaul at petiolar base, similar to basal leaves. Racemes many flowered, ebracteate, corymbose, elongated considerably in fruit; rachis straight; fruiting pedicels stout, horizontal, persistent. Sepals oblong, free, caducous, erect to ascending, equal, base of lateral pair not saccate; petals white or lavender, longer than sepals; blade spatulate, entire, obtuse at apex; claws obscurely differentiated from blade, shorter than sepals, glabrous, unappendaged, entire; stamens 6, only slightly exserted, erect, tetradynamous; filaments wingless, unappendaged, glabrous, free; anthers oblong, not apiculate at apex; lateral nectar glands annular; median glands confluent with laterals; ovules 78–120 per ovary; placentation parietal. Fruits dehiscent siliques, linear, terete, not inflated, unsegmented; valves thin leathery, obscurely veined, glabrous or pilose, smooth, wingless, unappendaged; gynophore obsolete; replum rounded, visible; septum complete, deeply invaginated between seeds, not veined; style distinct; stigma capitate, deeply 2-lobed, lobes not connivent, opposite replum, unappendaged. Seeds uniseriate, wingless, ovate, plump; seed coat not mucilaginous when wetted; cotyledons incumbent.
Monospecific; N Mexico, United States (SW Texas).
References: Payson (1922), Schulz (1924).