Solanum rostratum (Buffalo bur) - photos and description







Calyx very spiny

Calyx very spiny

Pods very spiny

Stems very spiny 


Top of leaf with spines

Bottom of leaf with stellate hairs

General: Annual plant, much branched from near the bottom. Very prickly, as prickly as a rose bush - stem, both sides of leaves, calyxes all with spines. Poisonous, labelled a noxious weed in the State of Washington.

Flowers: Flowers yellow, showy, in racemes growing along the stems and terminally. Flowers yellow, measured to 2.5 cm in diameter. The corolla spreading, with 5 anthers 4 of which are yellow and the same length, the fifth is longer and an incurved purple-reddish tip. The pistil is yellow in colour, thin, and longer than the anthers. The calyx is covered in long spines.

Leaves: Leaves alternate, are lobed or pinnatifid, we measured a leaf at 13 cm long by 10 cm wide. Leaf bottom and top armed with spines, leaves with stellate hairs.

Height: Height listed in Budd's Flora to 50 cm, we measured plants to 49 cm tall and spread of 120 cm.

Habitat: Waste ground. In its native habitat in the US can be found on disturbed soil and on dry prairie.

Abundance: Rare.

Origin: Introduced, although native to the US plains states such as Kansas.

When and where photographed: Weedy shoreline, home to Canada Geese who graze the vegetation on shore down to the dirt but do not touch this spiny plant, Wascana Park in our home of Regina, SK.