Althaea officinalis L.
Family: Malvaceae
Althaea officinalis image
Perennial herb 0.5 - 1 m tall Stem: erect, tall, branched, with upper surfaces concealed by a felt-like covering of forked or branched hairs. Leaves: many, alternate, stalked, velvety-downy, toothed, 5 - 10 cm long, egg-shaped with pointed tips, commonly shallowly three-lobed, the lobes also pointed. Flowers: many, axillary, stalked, showy, pale-rose to pink, about 3 cm wide, radially symmetric with five spreading petals, and sepals immediately subtended by six to nine narrow bractlets. The flowers may be solitary or clustered in the axils of upper leaves. Sepals: five, but fused at base, then separating into somewhat lance-shaped lobes covered with short, stiff appressed hairs. Petals: five, pinkish, 1.5 - 2 cm long, inversely egg-shaped with broad, often notched tips. Stamens: numerous, but filaments fused into an elongate, round (in cross section), hairy tube with the anthers protruding near the top. Pistil: enclosed by the stamen tube, with fifteen or more superior carpels (ovule-bearing structures), styles coming up through center of stamen tube, and ending with several, exserted, threadlike, side-facing (lateral) stigmas. Fruit: a ring of fifteen or more, hardened, crescent-shaped, single-chambered, single-seeded segments (mericarps).

Similar species: Althaea officinalis is similar to Alcea rosea but in that species the upper stem only has a patchy covering of mixed short appressed hairs and longer branched or unbranched spreading hairs, its leaves are larger (10 cm or more wide) and more rounded with rounded lobes, the larger flowers are almost stalkless and arranged in a spike-like inflorescence, the stamen tube is five-angled, and the individual fruit segments have two sections.

Flowering: July to September

Habitat and ecology: Introduced from Europe, known locally only from Berrien County, MI where reported as a garden escape.

Occurence in the Chicago region: non-native

Notes: The root tissues of this plant contain a sticky, gelatinous substance (mucilage) that was extracted to make the original marshmallows.

Author: The Field Museum

Erect, branched, 5-12 dm; lvs ovate, 5-10 cm, coarsely serrate and commonly shallowly 3-lobed, velvety; fls several in peduncled clusters from the upper axils, pink, 3 cm wide; bractlets narrowly lanceolate; 2n=42. Native of Europe; naturalized in salt marshes from Mass. to Va., and locally inland. July-Sept.

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

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