Chenopodium pumilio R. Br.

Chenopodium pumilio plant

Family - Chenopodiaceae

Stems - Herbaceous, from a taproot, to 25cm tall, simple to diffusely branched, erect, very fragrant, viscous, glandular with whitish glands, carinate, pubescent with multicellular trichomes.

Leaves - Alternate, petiolate, mostly pinnately lobed, fragrant. Petioles to 5mm long, pubescent and glandular as the stem but more so. Blades lanceolate, +/-1.3cm long, +/-9mm broad, cuneate at the base, pubescent adaxially, densely white glandular and pubescent abaxially.

Chenopodium pumilio leavesPressed leaves.

Inflorescence - Axillary glomerules of minute flowers. Each flower on a very short pedicel. Pedicels to .2mm long.

Flowers - Apetalous. Stamens 1-5 per flower. Anthers bilobed, pale yellow to white, .3mm broad. Ovary minute, green, glabrous, .2mm in diameter. Stigmas 2. Calyx accrescent, green, sepals 5, distinct, oblong linear, cupped, -1mm long, acute, glandular pubescent, mostly covering the seeds in fruit. Seeds rotund, .5mm in diameter, purplish, smooth.

Chenopodium pumilio flowersArrow shows flower cluster.

Flowering - July - October.

Habitat - Waste ground, disturbed sites, rocky or sandy soils, roadsides, railroads.

Origin - Native to Australia.

Other info. - This small species can be found mostly in the southern 1/2 of Missouri but its range is expanding. The plant is an exotic and thrives in disturbed areas. This is one of the easier species of Chenopodium to identify because of its strong fragrance, sticky stems, small size, and pinnately-lobed leaves.
A synonym is C. incanum (S. Wats.) Heller.

Photographs taken at Logan Creek, Reynolds County, MO., 7-13-03.