Common wireweed

Description

Sida acuta, the common wireweed, is a species of flowering plant in the mallow family, Malvaceae. It is believed to have originated in Central America, but today has a pantropical distribution and is considered a weed in some areas. In northern Australia, Sida acuta is considered an invasive species, and the beetle Calligrapha pantherina has been introduced as a biological control agent in an attempt to control the plant. Undershrub, with mucilaginous juice, aerial, erect, cylindrical, branched, solid, green. Alternate, simple, lanceolate to linear, rarely ovate to oblong, obtuse at the base, acute at the apex, coarsely and remotely serrate; petiole much shorter than the blade; stipulate, stipules free-lateral, unequally paired at the node, reticulate venation. Small, axillary, 2–3 in a cluster; pedicels jointed at the middle, epicalyx absent, complete, bisexual, regular, actinomorphic, hypogynus, pentamerous, yellow. Sepals: five, gamosepalous, campanulate, slightly accrescent, persistent, valvate. Petals: five, polypetalous but slightly connate below and jointed with the staminal column, twisted. Stamens many, monadelphous, arranged on the staminal column; staminal column is shorter than the petals, divided above into numerous filaments, anthers monothecous, reniform, basifixed, filament short, extrorse. Pollen are spherical with spikes, size is approximately 90 microns. Carples: five, syncarpous, ovary superior, penta or multilocular with axile placentation, one ovule in each locule; style 1, passing through the staminal tube; stigma globular, correspond to the number of carpels. A schizocarpic mericarp, seed 1 in each mericarp. Sida is a genus of flowering plants in the mallow family, Malvaceae. They are distributed in tropical and subtropical regions worldwide, especially in the Americas. Plants of the genus may be known generally as fanpetals or sidas. These are annual or perennial herbs or shrubs growing up to 2m tall (6 feet). Most species have hairy herbage. The leaf blades are usually unlobed with serrated edges, but may be divided into lobes. They are borne on petioles and have stipules. Flowers are solitary or arranged in inflorescences of various forms. Each has five hairy sepals and five petals in shades of yellow, orange, or white.