Solanum rostratum Dunal

Solanum rostratum plant

Family - Solanaceae

Stems - From thick taproot, to +30cm tall, herbaceous, erect, branching, multiple from base, with dense spines to +1cm long, stellate pubescent.

Leaves - Alternate, petiolate, (bi)pinnately lobed, spiny. Petiole to 9cm long, with spines. Blade to +12cm long, 10cm broad, stellate pubescent. Ultimate leaf divisions rounded.

Solanum rostratum leaf

Inflorescence - Racemes from side of stems to 15cm long. Peduncle spiny. Pedicels to +1cm long, spiny.

Flowers - Corolla yellow, -4cm broad, stellate pubescent externally, glabrous internally, funnelform, Margins of corolla undulate to slightly crisped. Stamens 5, adnate near base of corolla tube, 4 similar, 1 different. Filaments 2mm long, yellow, glabrous. Anthers yellow, 8mm long, connivent. Odd stamen to -1cm long, purplish-yellow, with flattened filament. Style yellow, glabrous, 1.7cm long, uncinate at apex. Ovary superior, glabrous (at least in upper half). Calyx tube to 2.5mm long, spiny, stellate pubescent, 5-lobed. Lobes to 8mm long, 2mm broad, linear, stellate pubescent. Fruit a globose berry surrounded by the accrescent calyx, to +1cm in diameter, many seeded.

Solanum rostratum flower

Solanum rostratum fruitsFruits.

Flowering - May - October.

Habitat - Pastures, waste ground, rocky open ground, moist soils, roadsides, railroads.

Origin - Native to the southwestern U.S., introduced into the midwest and further east.

Other info. - Nasty, nasty, nasty. This plant is not one to be handled or even stepped on. The spines are very dense, stiff, and sharp. The plant is just brutal. Identification in the field is easy, just touch it and you'll know what plant you have. It's actually quite nice to look at, just don't mess with it. This species is also somewhat toxic.

Photographs taken off Prairie View Rd., Platte County, MO., 6-2-00, and off Hwy 13, St. Clair County, MO., 8-15-03.


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