Proc. Biol. Soc. Wash. 29: 99. 1916.
Rhizomes erect or ascending, deeply buried, internodes 0.2-1.5 cm. Leaves: petiole 5-20 cm, sparsely crisped-hirsute. Leaf-blade almost always variegate with white or silver along veins, cordate to cordate-reniform, 4-14 × 3-12 cm, apex acute to broadly acuminate, rarely obtuse; surfaces abaxially sparsely hirsute, adaxially glabrous or sparsely hirsute along veins, marginal hairs ± perpendicular to margin. Flowers erect or nearly so; peduncle 1.2-1. calyx-tube subglobose, externally mottled red, sparsely to moderately hirsute, internally dark red, with purple hairs; distal portion of sepal erect or spreading at anthesis, 17-52 mm, apex filiform-attenuate, abaxially pale green, hirsute, adaxially tan or brownish green, rarely red proximally, puberulent with crisped purple hairs; pollen-sacs 0.8-2.4 mm, sterile tip of connective on inner stamens dark redbrown, 1.2-3.8 mm, longer than pollen-sacs.
Phenology: Flowering late winter–spring (Mar–Jun).
Habitat: Understory of dry or mesic forests, or exposed rocky slopes or roadcuts
Elevation: 200-1800 m
Asarum marmoratum is found only in the Cascades and the Siskiyou Mountains of southern Oregon and extreme northwestern California (M. R. Mesler and K. L. Lu 1990).
"broad" is not a number.