Common Name: Howell's Marsh Marigold, Marsh Marigold, Broad-leaved Marsh-marigold

(syn. C. biflora var. biflora, C. leptosepala var. howellii)

Note the leaves are as long as wide, generally toothed/scalloped. 5-12 white petals. Found at high elevations, wet soils, Cascades, OM.

There are a number of differences in how this species is dealt with.
Using H&C's "FPNW" and eFloras.org's "FNA"
Caltha leptosepala is morphologically complex, and a number of segregate taxa have been described. Plants are most commonly assigned to two species, C. leptosepala and C. biflora.

Caltha leptosepala (H&C gives 2 varieties) in the strict sense is only found in the Rocky Mountains of Arizona and New Mexico north to Alaska and is characterized by longer-than-broad leaves and single flowers per stem.

C. biflora (H&C gives 2 varieties) are found in the Coast Ranges of central California north to the coastal islands of southern Alaska, distinguished by broader-than-long leaves generally toothed with 1-2 flowers per stem.

After reviewing samples Morris in 1973 did not feel there were clear distinctions and felt the two species were slowly interbreeding.

From H&C
C. leptosepala: (leaves are longer than wide)
var. sulfurea: Canary-yellow sepals found in Lost River Mtns. at high elevations.
var. leptosepala: White or greenish or blue tinged sepals.

C. biflora: (leaves about as wide as long, generally toothed)
var. rotundifolia: leaves > 5 cm, found in e. OR through ID.
var. biflora: leaves < 5 cm found AK to CA.

west North Cascades; west Central Cascades
TRAILS: Yellow Aster Butte; Hope-Mig Lake; Tomyhoi Lake; Schreiber's Meadow
HABITAT: wet meadow
ELEVATION: 1,465 m (4,805 ft.); 1,305 m (4,280 ft.); 1,670 m (5,480 ft.); 1,075 m (3,530 ft.)
BLOOM TIME: 17-JUL; 27-JUN; 19-AUG; 21-JUN