Canada

Wild rose, spiny spider flower

Cleome aculeata

Stem: Erect annual herb up to 50 cm tall, with prickles on stem.
Leaves: Leaves mostly trifoliolate with simple leaves or bracts produced below each flower. Leaflet blades 48-85 x 28-45 mm, leaflet stalks nil or 2-3 mm long. Stipules spiny, curved, 1-3 mm long.
Flowers: Pedicels 20-30 mm long, flowers 10-12 mm diam. Calyx lobes about 3 mm long. Corolla lobes 6-7 mm long, clawed, i.e. stalked. Anthers about 2 mm long, filaments about 4 mm long. Pollen yellow. Stamens and ovary seated on a green disk. Ovary about 2 mm long. Stigma sessile. Ovules numerous on each placenta.