Ligusticum canadense (L.) Britt.

Ligusticum canadense plant

Family - Apiaceae

Stems - To 2m tall, erect, branching in inflorescence, fistulose, glabrous, glaucous, herbaceous, with striate venation, from a big taproot.

Leaves - Alternate, sessile, sheathing, ternate, to +45cm broad, +40cm long, glabrous. Petiolules with adaxial grooves. Leaflets oblong-ovate to ovate, coarse serrate, dark green above, lighter green below, acute, to +/-11cm long, +/-6cm broad.

Ligusticum canadense leaf52mm lens cap shown for scale.

Ligusticum canadense leafletsClose-up of leaflets.

Inflorescence - Lateral and terminal compound umbels. Main rays of inflorescence typically subtended by linear lanceolate to trifoliolate bracts. Rays and raylets glabrous. Rays to +/-6cm long, striate. Raylets to +/-2.5cm long. Pedicels to 5mm long in flower. Flowers +/-15 per umbellet.

Ligusticum canadense bractsBracts subtending the main rays.

Flowers - Staminate flowers - Petals 5, white, inflexed at apex, glabrous, clawed, to 2mm long, 1mm broad, apiculate. Stamens 5, spreading, alternating with the petals. Filaments white, glabrous, 1.5mm long. Anthers pale yellow, .4mm broad and long. Styles reduced to a plump stylopodium. Calyx flattened, glabrous, short 5-lobed. Lobes irregular, .2mm long. Pistillate flowers - Style minute, expanded into plump large stylopodium to 1.7mm broad. Caylx lobes slightly longer than in staminate flowers, triangular. Ovary inferior, ribbed, glabrous, 1.1mm long, 1mm broad in flower, 2-carpellate. One ovule per carpel.

Ligusticum canadense flowersFlowers and umbellets.

Flowering - May - July.

Habitat - Rocky woods, ravines, along creeks, slopes, bluffs.

Origin - Native to U.S.

Other info. - This large member of the carrot family is easy to ID when in flower because of its large size, big leaves, and glaucous stems. Like many plants in this family, L. canadense has a licorice smell when crushed. This species can be found in the Ozark region of Missouri.

Photographs taken at the Noblett Lake Recreational Area, Douglas County, MO., 5-18-01.