Hibiscus asper Hook.f.

Global description

Hibiscus asper is an erect plant with sturdy stem reaching up to 2 m high. The whole plant is strongly rough, almost thorny. The alternate leaves are variable in shape, often very cut. A gland is located at the base of the central rib under the lamina. The large white to pale yellow flowers are located at the leaf axils. Epicalyx with simple triangular tines. Calyx with 5 sepals covered with 3 lines of red dots and a central wart.
 
Cotyledons

Cotyledons are suborbicular-polygonal, 1 to 2 cm in diameter; sinuated edge, scalloped at the top; narrowed-attenuated almost at right angles on the petiole; the leaf blade is glabrous and trinervate; the petiole is shorter or equal to the lamina and is highly bristling with a depression on the upper side.
 
First leaves

The first leaves are alternate and polymorphic from one individual to the other and on the same individual. The first leaf is still sinuate to trilobed towards its base. The second leaf may either broaden in oval-triangular leaf with three basal shallow lobes or divided almost to the petiole in 3 then 5 or 7 segments, themselves serrated or lobed- serrated. On the underside, a cup-shaped gland lies just at the point of divergence of the palmate ribs; filiform stipules are inconspicuous. The leaves are covered on both sides with a thick bristles joined in stellate beam.
 
General habit

Erect growth habit, with an almost unbranched trunk, annual, little or shortly branched, especially towards the base, which can exceed 2 m high.
 
Underground system

Taproot system
 
Stem

The stem is robust, cylindrical, fluted; it is dotted with stellate hairs, rigid with tuberculate base. Rough to the touch, particularly dense on 2 lines in the extension of insertion of the petioles.
 
Leaf

The leaves are alternate; filiform stipules, 1 to 3 mm; petioles 2 to 10 cm long, with a pubescence of dense to loose stellate hairs; Lamina of variable shape and dimensions,(up to 15 cm) from  oval leaf to the leaf almost compound palmate with linear lobes. In all cases, the margin is very irregularly serrated  serrated- reserrated. Stellate hairs of variable density on the two sides of the leaf blade. An elongated cup-shaped gland at the base of the main central rib on the underside.
 
Inflorescence

The inflorescences are formed of large flowers (1-2 or 3) in the axils of leaves.
 
Flower
 
The flower has a white to pale yellow corolla, shortly campanulate, with the inside center red. Epicalyx is present with a dozen of simple thick, green triangular lobes. . The calyx consists of 5 thick, long-pointed sepals, with 3 bands of red tuberculate points, and carrying a cup-shaped wart gland in the middle of the center line.
 
Fruit
 
The fruit is a spherical to ovoid pubescent capsule.
 
Seed
 
The seed is 3 mm long and wide, with lateral triangular profile and oval-lanceolate facial profile with a triangular transverse section (the convex dorsal side, the flat side faces), gray beige, covered with small dark brown sharp asperities.

Origin

Hibiscus asper is native to tropical Africa.

Worldwide distribution

This species has been introduced into the Caribbean, Central and South America, as well as Asia.

https://www.gbif.org/species/3152547