Croton willdenowii G.L. Webster

Common Rushfoil

Croton willdenowii plant

Family - Euphorbiaceae

Stems - To +/-40cm tall, divaricately branching, lepidote, from a slender taproot, erect, herbaceous (but tough near the base), single or multiple from base.

Croton willdenowii stem

Leaves - Alternate, petiolate. Petiole to +2mm long, lepidote. Blade linear to elliptic-ovate or linear-ovate, entire, to -4cm long, +/-2cm broad, lepidote (more so below), mucronate to apiculate, typically silvery below and appearing spotted because of the scales, green above. Leaves often folded in dry weather.

Croton willdenowii leafAbaxial surface of the leaf.

Inflorescence - Small terminal racemes to -1cm long. Racemes androgynous.

Croton willdenowii inflorescence

Flowers - Staminate flowers with 4-6 stamens. Filaments white, 1.5mm long, glabrous. Anthers white, .4mm broad. Petals 4, 1.1mm long, white. Sepals 4, .7mm long, acute, densely stellate pubescent. Pistillate flowers 5-lobed(calyx). Lobes 2mm long, attenuate, densely stellate pubescent. Ovary ovoid, 1.2mm long, densely stellate pubescent. Styles 2, bifurcate and appearing as 4 or more, 1mm long. Capsule green, lepidote, 4mm long, ovoid but slightly compressed, 1-seeded.

Croton willdenowii flowerStaminate flower close-up.

Flowering - May - September.

Habitat - Acidic soils of glades, rocky open woods.

Origin - Native to U.S.

Other info. - This is a typical glade species in Missouri. It can be found in the southern half of the state. The plant is very easy to identify in the field because the entire plant is covered silvery scales (lepidote). This is a small species but it is quite prevalent on glades with acid substrates.

Photographs taken off Hwy. H, Shannon County, MO., 7-18-03.