Order 20. MALVÀCEÆ. (Mallow Family.)
Herbs or shrubs, with alternate stipulate leaves and regular flowers, the calyx valvate and the corolla convolute in the bud, numerous stamens monadelphous in a column, and united at base with the short claws of the petals, 1-celled anthers, and kidney-shaped seeds.—Sepals 5, united at base, persistent, often involucellate with a whorl of bractlets forming a sort of exterior calyx. Petals 5. Anthers kidney-shaped, opening along the top. Pistils several, the ovaries united in a ring or forming a several-celled pod. Seeds with little albumen; embryo curved, the leafy cotyledons variously doubled up.—Mucilaginous, innocent plants, with tough bark and palmately-veined leaves. Flower-stalks with a joint, axillary.
Tribe I. MALVEÆ. Columns of stamens anther-bearing at the top. Ovaries and carpels 5–20 or more, closely united in a ring around a central axis, from which they separate after ripening.
[*] Stigmas occupying the inner face of the styles; carpels 1-seeded, falling away separately.
1. Althæa. Involucel of 6 to 9 bractlets.
2. Malva. Involucel of 3 bractlets. Petals obcordate. Carpels rounded, beakless.
3. Callirrhoe. Involucel of 1–3 bractlets or none. Petals truncate. Carpels beaked.
4. Napæa. Involucel none. Flowers diœcious. Stamens few (15–20). Carpels beakless.
[*][*] Stigmas terminal, capitate; carpels 1–few-seeded, usually dehiscent.
5. Malvastrum. Involucel of 3 bractlets or none. Seed solitary, filling the cell, ascending.