Appearance

Abutilon grandifolium is a large shrub 3.3-10 ft. (1-3 m) tall, stems, petioles, and pedicels stellate tomentose and pubescent with spreading, shiny, simple hairs up to 0.2 in. (5 mm) long. It is relatively common weed of waste areas, disturbed sites, roadsides and drains, but is also an occasional weed of disturbed and undisturbed natural ecosystems such as tall shrublands, grasslands and riparian areas. Abutilon grandifolium is native to South America.

Foliage

Leaves are heart shaped. Leaf blades are ovate to orbicular, from 3-7 in. (8-18 cm) long with dentate margins. The apex is acuminate and the base is deeply cordate with the lobes often overlapping. The petiole ranges from 2-4 in. (5-10 cm) long.

Flowers

Flowers are solitary or in groups of 2-6 in naked cymes, exceeding the leaves. The peduncles and pedicels are up to 4 in. (10 cm) long and articulate. The calyx is about 0.4-0.6 in. (1.1-1.5 cm) long at the anthesis and lobed to near base. It is accrescent and loosely surrounds the fruit. The corolla is cup-shaped to subrotate with yellow to yellowish orange petals about 0.5-0.8 in. (1.2-2 cm) long. Petals are undulate-dentate apically with a staminal column approximately 0.2-0.3 in. (5-8 mm) long. The yellow style branches and the stigmas are maroon.

Fruit

The schizocarp is a dull black and broadly urceolate-truncate. It is about 0.4-0.6 in. (11-14 mm) long. The mericarps are usually 10, thin-walled and somewhat inflated. They are short-beaked dorso-ventrally. There are usually 3-6 seeds per mericarp. They are blackish and reniform. Seeds are about 0.08-0.12 in. (2-3 mm) long and sparsely pubescent.

Ecological Threat

Abutilon grandifolium has escaped in Hawaii and naturalized in waste areas, fields, and along roadsides, especially in arid regions, from near sea level up to 1970 ft. (600 m). It is a widespread tropical weed, although it is still grown in some areas for fiber or as an ornamental. Abutilon grandifolium has also escaped and naturalized in disturbed habitats in parts of Australia, New Zealand, French Polynesia and Niue. It can be especially troublesome in riparian habitats.

Selected Images

Maps

Invasive Listing Sources

• Jil M. Swearingen, Survey of invasive plants occurring on National Park Service lands, 2000-2007
• WeedUS - Database of Plants Invading Natural Areas in the United States

References