General: Dioecious perennial herb from creeping, scaly rhizome and thin and fibrous roots; stems erect, 30-100 cm tall, simple or branched, smooth.
Leaves: Mostly stem leaves, alternate, with flaring stipular sheaths, the basal and stem leaves stalked, 3- to 4-times 3-parted, the leaflets smooth to glandular, circular to egg- or wedge-shaped or heart-shaped, 10-30 mm wide, tips 3-lobed, the lobe margins round-toothed.
Flowers: Inflorescence a many-flowered, open, terminal panicle, the lower bracts like reduced leaves, the upper small, simple; flowers unisexual, male and female flowers on separate plants; flower stalks about equal in length; petals absent; sepals usually 4 (-6), greenish-whitish to purplish-tinged, egg-shaped, 3.5-4.5 mm long in male flowers, 1.5-2 mm long in female flowers; stamens 15-30, the filaments purplish, threadlike, 4-10 mm long, the anthers 1.5-4 mm long, sharp-pointed; stigmas often purplish.
Fruits: Achenes, 6-9, spreading to bent back, spindle-shaped, 6-9 mm long, glandular, strongly 3-veined on each side, stalks 0.4-1.2 mm long; beaks 3-4.5 mm long.
Notes: A highly variable species, without sufficiently differentiated phases.
Moist to mesic meadows, thickets, clearings and open forests from the lowland to subalpine zones; common throughout BC except Queen Charlotte Islands, N Vancouver Island and the adjacent coast; N to SE AK, YT and NT, E to SK and S to CO, UT and N CA.
A shade-tolerant/intolerant, submontane to subalpine, Western North American forb distributed equally in the Pacific and Cordilleran regions, and marginally in the Central region. Occurs on fresh to very moist, nitrogen-rich soils within montane boreal, temperate, and cool mesothermal climates; its occurrence decreases with increasing elevation and latitude. Common and often plentiful in the herbaceous understory of opencanopy forests on water-shedding and water-receiving sites; occasionally inhabits exposed mineral soils on disturbed sites; tolerates fluctuating groundwater tables. Often associated with Athyriumfilix-femina, Cornus sericea, Gymnocarpium dryopteris, Lonicera involucrata, Oplopanax horridus, Ribes lacustre, and Tiarella trifoliata. A nitrophytic species characteristic of Moder and Mull humus forms.
Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2020. E-Flora BC:
Electronic Atlas of the Plants of British Columbia [eflora.bc.ca]. Lab for
Advanced Spatial Analysis, Department of Geography, University of British
Columbia, Vancouver. [Accessed:
2022-08-16 12:51:26 AM
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