71. Microthlaspi F. K. Meyer, Feddes Repert. 84: 452. 1973.
[Greek micro-, small, and genus Thlaspi]
Ihsan A. Al-Shehbaz
Annuals; not scapose; (glaucous). Stems erect or subdecumbent, unbranched or branched. Leaves basal and cauline; petiolate, sessile, or subsessile; basal (withered by fruiting), loosely rosulate or not; petiolate [subsessile], blade margins entire or obscurely dentate; cauline blade (base cordate to amplexicaul), margins entire or repand. Racemes (several-flowered), considerably elongated in fruit. Fruiting pedicels divaricate, straight or recurved, slender. Flowers: sepals ovate or oblong, (margins membranous); petals white, oblong or spatulate, (sometimes slightly unequal), claw (short or) undifferentiated from blade, (apex rounded [obtuse]); stamens slightly tetradynamous; filaments not dilated basally; anthers ovate, (apex obtuse); nectar glands (2 or 4), lateral, 1 on each side of lateral stamen (when 4). Fruits sessile, usually obcordate, rarely obovate, (apex emarginate), strongly angustiseptate; valves keeled, (winged around, much wider apically); replum rounded; septum complete, (not veined); ovules (4-)6-8(-10) per ovary; style obsolete or distinct, (included in apical notch of fruit); stigma capitate. Seeds plump, not winged, ovoid; seed coat (smooth), mucilaginous when wetted; cotyledons accumbent. x = 7.
Species 4 (1 in the flora): introduced; Europe, Asia, n Africa.
SELECTED REFERENCES Koch, M. et al. 1998b. Molecular biogeography and evolution of the Microthlaspi perfoliatum s.l. polyploid complex (Brassicaceae): Chloroplast DNA and nuclear ribosomal DNA restriction site variation. Canad. J. Bot. 76: 382-396. Meyer, F. K. 2003. Kritische Revision der "Thlaspi"-Arten Europas, Afrikas und Vorderasiens. Spezieller Teil. III. Microthlaspi F. K. Mey. Häussknechtia 9: 3-59.
