Malvastrum coromandelianum (L.) Garcke

Global description

Malvastrum coromandelianum is an erect plant or subshrub. The main stem is straight and hairy, the root is a taproot. The leaves are alternate, simple, elongated, slightly covered with hair at 4 points associated in pairs, and strongly serrated. The flowers are solitary or in small groups in terminal position or at the base of the leaves. They are pale yellow to yellow-orange. The fruits are dry, flattened, hairy and disc-shaped parting in 10 to 12 quarters at maturity. They have a big spine at the top and two small on the sides.
 
Cotyledons

Cotyledons have short stalked. The blade is oval with rounded base and obtuse, slightly emarginate top, 6 mm long and 5 mm wide. Pronounced midrib.

First leaves

First leaves are simple, alternate, petiolate. Lamina is round becomingoval to elliptical. Base is slightly cordate, rounded apex,  leaf margin is crenate to serrated. Pinnate nerves clearly visible. The stem and the leaves are covered with double navicular hairs.
 
General habit

Erect plant, sub-woody, branched, 30 to 90 cm high, quickly lignified.

Underground system

Deep taproot, very difficult to uproot.

Stem

Stem is cylindrical, full, up to 1 cm thick. Green when young, and turns brown when older. It is covered by navicular double features hairs,

Leaf

Leaves are simple, alternate, held by a petiole 0.7 to 4 cm long. At the base of the petiole, are two linear stipules, 5 mm long and quickly deciduous. Lamina ovate to elliptic, 3 to 5 cm long and 2 to 2.5 cm wide. Pinnate venation depressed on the upper surface and prominent on the lower surface. The base is wedge or truncated, apex is obtuse or acute. The margin is strongly serrated. The upper surface is dotted with simple applied hairs, the lower surface is covered with a pubescence of  navicular double hairs.
 
Inflorescence

Flowers are axillary, solitary or in small groups of 2 to 6 on short lateral branches (more or less leafless) with peduncles 2 to 5 m and accrescent.
 
Flower

Epicalyx is composed of 3 lanceolate bracts, 5 to 6 mm long, acute, pubescent. Calyx 7 to 9 mm long, slightly accresent, with 5 oval sepals fused to the bottom, acuminate on the top, pubescent. Corolla has 5 petals and is obovate, asymmetrical at the top, 1 cm long, pale yellow to orange yellow. Ovary superior, with 10 to 12 carpels.  The stamens are in staminal tube fused to numerous anthers
 
Fruit
 
The fruit is a discoid capsule, 7 mm in diameter, separating in 10 to 12 mericarps at maturity. The lateral sides have prominent venations with rounded back two short edges, divergent and at the top with a long edge, 0.5to 1mm. The superior part is more or less hairy, with simple hairs. The lower and lateral parts have shorter hairs more or less stellate.

Seed

Seeds are kidney shaped, thick, about 2 mm long and 2 mm wide reddish brown. It is included in the mericarps.

Origin

Malvastrum coromandelianum is native to Central and South America and the Caribbean region.

Worldwide distribution

This species is present in West Africa, East and South Africa, Indian Ocean islands (Madagascar, Reunion, Mauritius, Seychelles), India and Southeast Asia, Australia and Pacific Islands.

https://www.gbif.org/fr/species/3152268