Fatoua villosa (Thunb.) Nakai
Family: Moraceae
Hairy Crabweed
Fatoua villosa image
Herbs , to ca. 8 dm. Stems erect, branched, pubescent with hooked trichomes. Leaves: stipules linear to linear-lanceolate, 1.8-2.5 mm; petiole 1-6 cm, often ± as long as leaf blade. Leaf blade to 2.5-10 × 1-7 cm, papery, base cordate to truncate, margins crenate-dentate, apex acute to acuminate; surfaces abaxially and adaxially appressed-hirsute. Inflorescences cymes, dense, 4-8 mm wide, subtended by narrow bract; peduncle 1-2 cm. Flowers light green, staminate and pistillate in same cyme. Staminate flowers: calyx campanulate; stamens exserted. Pistillate flowers: calyx boat-shaped; ovary globose, puberulent, somewhat depressed in axis; style reddish purple, filiform. Achenes white, oval, 3-angled, ca. 1 mm, minutely muricate, with 2 triangular, membranous appendages. Seeds explosively expelled. Flowering summer-fall. Disturbed sites; 0-300 m; introduced; Ala., Ark., Fla., Ga., Ky., La., Md., Miss., Mo., N.C., Ohio, Okla., S.C., Tenn., Tex., Va., W.Va.; West Indies (Bahamas); native to Asia. Fatoua villosa was first reported for North America from Louisiana by J. W. Thieret (1964). It has become widespread in the eastern and lower midwestern states where it often occurs as a weed in greenhouses and disturbed sites. Apparently it spreads from the distribution of horticultural materials.

Annual herb to 0.8 m tall Stem: erect, branched, with hooked hairs. Leaves: alternate, the stalk nearly as long as blade with linear to lance-shaped stipules at the base. The blades are 2.5 - 10 cm long, 1 - 7 cm wide, egg-shaped with a squared to heart-shaped base and a short to long-pointed tip, somewhat round-toothed, and stiffly hairy above and beneath. Flowers: either male or female, found on the same tree (monoecious), borne on dense flat-topped inflorescences (cymes), purple fading to dark brown, 4 - 8 mm wide, short-lived. Fruit: a spherical multiple of achenes, borne near the leaf axils, very short-stalked. Each achene is white, 1 mm long, oval, three-angled, covered with tiny bumps (muricate), and has two thin appendages at the tip. Seeds are forcefully expelled when ripe.

Similar species: Fatoua villosa can resemble seedlings of Morus sp. However, Morus sp. seedlings have hairless stems and will eventually mature into trees.

Flowering: summer to fall

Habitat and ecology: One specimen was collected from a weedy side of a house in Cook County. It appears to be spreading in the yard. Elsewhere in the United States, it often grows in disturbed sites and greenhouses.

Occurence in the Chicago region: non-native

Notes: This species was introduced from Asia. It is spreading from the southeastern United States, often by way of potted horticultural crops.

Etymology: Fatoua derivation unknown. Villosa means covered with soft hairs.

Author: The Morton Arboretum