Hibiscus panduriformis Burm.f.

Hibiscus panduriformis is a velvety-tomentose subwoody plant, with long irritating hairs reaching up to 5 mm long. The leaves are simple, alternate, stalked, broadly ovate-cordate, rounded and angular or slightly lobed, always serrated or bristled, very woolly. The flowers are axillary and briefly stalked, involucre of 6-8 linear tomentose bracts, with cup-shaped calyx, strongly tomentose-ciliate, with yellow corolla with, at the base, a large purple stain. The numerous stamens are united over the greater part of their length in a staminal column of 8 to 20 mm long.
 
Cotyledons

Cotyledons are stalked with oval blade, with slightly cordate base, rounded tip, light green, trinervate.
 
First leaves

The first leaves are simple, alternate, with pubescent petiole, 1.5 to 3.2 cm long, with corded ovate blade, 2 to 3.5 cm long and 1.5 to 2.5 cm wide, acute apex, entire margin, light green, both surfaces pubescent, trinervate.
 
General habit

Hibiscus panduriformis is an upright and branched subwoody plant, annual to perennial of short lifespan, reaching up to 3 m high; stems, branches and leaves are velvety-tomentose, with some irritating stiff bristles.
 
Underground system

Taproot system.
 
Stem

The stem is cylindrical, erect and branched, tomentose and has long irritating simple or branched hairs reaching up to 5 mm long.
 
Leaf

The leaves are simple, alternate, quite lengthily stalked (petiole 2-18 cm long), with ovate- cordate blade or with orbicular outline, 4 to 18 cm long and 3 to 12 cm wide, not lobbed to weakly 3- 7-lobed, serrated or crenelated edge, obtuse to acute apex, both surfaces pubescent and hairy, distinctly 5-7-veined.
 
Inflorescence

Flowers arranged in groups of 1 to 4 axillary flowers, briefly stalked: peduncle of about 0.5 cm rarely reaching 2cm; involucre of 6 to 8 linear, tomentose bracts, sometimes slightly dilated towards the apex, equaling the calyx when young but ultimately shorter.
 
Flower

Regular flowers, bisexual, 5-merous, 3.5 to10 cm in diameter: cup shaped calyx, strongly tomentose-ciliated, lobed up to mid-length, about 1 cm long, slightly accrescent (up 1, 5 cm). triangular lobes, trinervate, non anastomose veins, exposed at fruit maturity; yellow corolla with, at the base, a large purple stain, sometimes invading the whole of the petals, 2.5 to 5 cm long, covered with dense bristles outside; staminal column shorter of 15 to 25 mm long, with stamens over the entire length; the ovary is superior, with a style of 10 to 15 mm longer than the staminal column, with branches of 30 to 50 mm long.
 
Fruit

The fruit is an ovoid to sub-globular capsule, 10 to 18 mm by 8 to 15 mm, acuminate, covered with stiff bristles, leathery at maturity.
 
Seed

Seeds are numerous, cuneiform, about 3 mm long and 2 mm wide, brown, striped and covered with small brown hairs.