Thlaspi arvense L.
Family - Brassicaceae
Stems - To .75m tall, glabrous,
herbaceous, erect, branching above near inflorescence, ribbed,
somewhat purplish near base, single or numerous from roots. Roots thickened.
Leaves - Basal leaves in
rosette, spatulate, oblong, or narrowly obovate, glabrous, very shallowly
toothed or lobed, to +8cm long, 2cm broad, soon wilting. Petiole winged.
Cauline leaves alternate, clasping, lanceolate to lanceolate-oblong, glabrous,
+/- 6cm long, 2cm broad, coarsely toothed or lobed, auricles pointed.
Inflorescence - Compact terminal
racemes, elongating in fruit to +30cm tall(long).
Flowers - Petals 4, white,
clawed, to 4mm long, 1.5mm broad, glabrous. Stamens 6, divided into 2 sets
of 3 on either side of flattened ovary, included to equaling corolla.
Stigma sessile. Sepals 4, free, spreading to erect in flower, with whitish-yellow
margins, 2mm long, +1mm broad, ovate, typically glabrous. Pedicels to 1cm
long in flower, greatly increased in fruit. Silicles, to +15mm long and wide, with small notch at apex, on pedicels to +2cm long, glabrous, with numerous seeds.
Flowers close-up.
Calyx close-up.
Fruits.
Flowering - April - June.
Habitat - Waste ground, disturbed
sites, roadsides, railroads, pastures.
Origin - Native to Europe.
Other info. - This is one
of the most easily recognized members of the Brassicaceae
because of its large and plentiful fruits which have the characteristic "cabbage" flavor when chewed. Like most of the other introduced members of this family, it is abundant.
Photographs taken at the Kansas City Zoo, 5-11-00, and at Danville Conservation Area, Danville, MO., 4-1-04 and 5-3-04.
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