Operculina turpethum (L.) Silva Manso

Global Description
Operculina turpethum is a perennial grass, vigorous, twining or prostrate, branched, reaching a length of 5 m or more. The slender stems are more or less angular, glabrous to briefly hairy, often purplish in colour. The simple and alternate leaves are stalked, petiole 1 to 7 cm long, leaf blade of quite variable shape and size: broad to narrowly lanceolate ovate, 2.5 to 8 cm long and 1 to 7 cm wide, cordate base. The inflorescence is composed from 1 to 3 axillary flowers with long stalks of 2 to 6 cm, corolla in very open funnel, 30 to 45 mm long, white or sometimes slightly pinkish or yellowish at the bottom.
 
Cotyledons
 
The cotyledons are quite remarkable, with petiolated leaf blade and deeply bilobed, diverging in V-shaped up more than half of its length, with two pairs of more or less arched lateral veins; the lobes have a rounded top.
 
First leaves
 
The first leaves are rather long-stalked, oval-lanceolate to elliptic lanceolate lamina, cuneate base and sub-acuminate apex, pinnately veined with very prominent midrib.
 
Growth habit
 
Operculina turpethum is a perennial vine, vigorous, twining or creeping, fleshy and branched, reaching a length of 5 meters or more, with slender stems more or less angular and winged.
 
Underground unit
 
Taproot
 
Stem
 
The stem is slender, more or less angular, with 3 to 5 ondulated wings, or sometimes cylindrical, glabrous to slightly hairy, often purplish.
 
Leaf
 
The leaves are simple and alternate, stalked, petiole 1 to 7 cm long, sometimes winged. The blade is very variable in shape, usually triangular, truncated or broadly wedge at the base, acute or obtuse at the apex, sometimes oval to broadly ovate to lanceolate then cordate at base, acute to sub-acuminate and mucronate at the apex . The margin is entire. It is pubescent on either sides or more or less glabrous on the upper face.
 
Inflorescence
 
The inflorescence constitutes of 1 to 3 flowers in the axils of leaves; they are carried by a pubescent peduncle of 2 to 6cm long, sometimes winged; the pedicel of each flower is 0.5 to 2 cm long. Floral bracts are broadly ovate to elliptic-obovate, pubescent on the back, rapidly deciduous.
 
Flower
 
The flowers are bisexual, regular, 5-merous: sepals are unequal, broadly ovate to elliptic, the outer are about 15 mm long and 10 mm wide, acute and mucronate; the inner are approximately 13 mm long and 8 mm wide, subacute. Corolla in very open funnel, 30 to 45 long mm, is white; sometimes the bottom of the tube is pink or pale yellow. The stamens are inserted approximately 5 mm from the base of the corolla, with filament of 6 to 8 mm long, with papillose and broad base; the sagittate anthers are 4 mm long, twisted. The ovary is spherical, smooth, about 2.5 mm high, with 2 biovulate loculus, carried by a cylindrical pedestal above 1.5 mm high; filiform style of approximately 15 mm long.
 
Fruit
 
The fruit is a characteristic globular capsule, very depressed, about 1 to 1.5 cm in diameter, briefly apiculate, surrounded by accrescent sepals up to 20 mm, usually containing 3-4 black and smooth seeds.
 
Seed
 
The seed is ellipsoidal-globular, about 6 x 5 x 5 mm with black seed coat, smooth with a few hairs.