37. Turritis Linnaeus, Sp. Pl. 2: 666. 1753; Gen. Pl. ed. 5, 298. 1754.
Tower-mustard, towercress [Latin turris, tower, alluding to pyramidal shape of plants due to overlap of leaves and fruits]
Ihsan A. Al-Shehbaz
Biennials or, rarely, perennials (short-lived); not scapose; (glaucous distally), glabrous or pubescent (mostly proximally), trichomes simple and/or stalked, forked, or substellate. Stems erect, unbranched basally, often branched distally. Leaves basal and cauline; petiolate or sessile; basal rosulate, petiolate, margins usually dentate, sinuate, repand, or pinnatifid, rarely entire; cauline blade (base auriculate or sagittate [amplexicaul]), margins dentate or entire. Racemes (corymbose), considerably elongated in fruit. Fruiting pedicels erect [divaricate], (appressed to rachis), slender. Flowers: sepals erect, oblong or linear, (margins membranous); petals usually yellowish or creamy white, rarely pink [purplish], usually narrowly spatulate or linear-oblanceolate, rarely linear, claw not differentiated from blade, (apex obtuse); stamens (erect), tetradynamous; filaments not dilated basally; anthers narrowly oblong [linear], (apex obtuse); nectar glands confluent, subtending bases of stamens, lateral glands annular, median glands present. Fruits siliques, dehiscent, sessile, linear, smooth, often subterete-quadrangular, (leathery); valves each with prominent midvein, glabrous; replum rounded; septum complete, (membranous, veinless); ovules 130-200 per ovary; (style distinct, short, stout); stigma capitate, (subentire). Seeds biseriate, flattened, not winged or, rarely, narrowly winged, oblong or subglobose [elliptic, orbicular]; seed coat not mucilaginous when wetted; cotyledons accumbent. x = 6, 8.
Species 2 (1 in the flora): North America, Eurasia, n Africa.
SELECTED REFERENCE Dvoák, F. 1967. A note on the genus Turritis L. Oesterr. Bot. Z. 114: 84-87.