Herbs perennial, 0.4–2 m. Stems erect, branched distally, softly stellate-tomentose. Leaves: stipule somewhat persistent, linear, simple, 2–5 mm, white pilose-hairy; petiole 0.5–5 cm, stellate-hairy; blade orbiculate, palmately divided, 5-lobed, 5–7 × 6–8 cm, lobes lanceolate, 0.5–5 × 0.3–3.5 cm, base truncate, margins irregularly serrate, apex obtuse, upper leaves reduced, orbiculate-triangular, 3–5-lobed, 1–6 × 0.6–5 cm, middle lobe longer than others, surfaces stellate-hairy. Inflorescences 1–4-flowered fascicles in leaf axils or peduncles many-flowered; peduncles 0.5–3 cm. Pedicels 0.1–5 cm, densely stellate-hairy; involucellar bractlets 6–10, linear-lanceolate, free portions 2–6 × 0.5–2 mm, 1/2+ as long as calyx, margins entire, apex acuminate, densely stellate-hairy. Flowers: calyx 8–10 mm, not or only slightly accrescent, lobes lanceolate, margins entire, apex acuminate, stellate-hairy; petals lilac-purple, 9–15 × 4–6 mm, 1.1–1.5(–3) times as long as calyx, margins entire, apex obtuse or slightly notched; staminal column 1–3 mm, glabrous or rarely sparsely papillose-hairy; anthers in upper 1/2, purple; style 10–20-branched. Fruits partially concealed by incurved calyx lobes, 7 mm diam.; mericarps 10–20, erect, brown, unwinged, orbiculate, rugose, stellate pilose-hairy, sides glabrous. Seeds brown, reniform-round, 1–2 × 2–2.5 mm, glabrous. 2n = 84.
Phenology: Flowering summer–fall.
Habitat: Wet or moist ditches, disturbed areas, stream drainages
Elevation: 300–400 m
Introduced; S.Dak., w Asia (n Iran, s Russia, Turkey, Turkistan).
Althaea armeniaca is very similar to A. officinalis and is known to hybridize with it. Althaea armeniaca differs primarily by the more deeply five-lobed leaves rather than the three in A. officinalis and can be distinguished from A. cannabina by its pubescent fruits. Only a single population is known from the flora area, found in Hutchinson County, near Lonetree Creek west of Olivet. The species dominated a fence row at the edge of a field and was locally common in scattered clumps over an area of about three miles.