Ipomoea dichroa (Roem. et Schult.) Choisy

Global description

Ipomoea dichroa is a voluble lianascent plant with long hairs tuberculate at the base. The leaves are alternate, simple and trilobed. The upper face is green while the underside is white due to woolly pubescence appressed. The flowers are small, purple in color and assembled in small cymes in the axils of the leaves. The fruit is a dehiscent capsule containing 4 highly pubescent seeds.

Cotyledons

The cotyledons are remarkable by their bilobed V shape. The base of the blade is slightly rounded, with a small tooth on each side. The top of the lobes is rounded. Each lobe is 3 cm long and 5 to 6 mm wide. The cotyledons are borne by a short petiole, from 5 to 6 mm.

First leaves

The first leaves are alternate and simple. They are oval, with a broad base slightly corded and the apex acuminate. The limb is divided into 3 palmate lobes from the second or third leaf.

General habit

The plant is lianascent. The plant is very voluble and wraps on any support. It is not very ramified. The main axis can reach 2 m long.

Underground system

The root is a taproot. It can become woody and thick in perennial individuals.

Stem

The stem is cylindrical, slightly polygonal. It is hollow. It is covered with a strong pubescence of erect hairs 1 to 2 mm long, with a purplish, tubercular base.

Leaf

The leaves are alternate and simple. They are borne by a petiole 3 to 6 cm long and covered with long hairs. The blade is palmately trilobed, 5 to 8 cm long and wide, slightly longer than wide. The base is weakly corded. The top of the middle lobe is acuminate. Lateral lobes, shorter, have a corner top. The margin is entire. The upper face is green, covered with a pubescence of long, scattered hairs. The lower face is silvery white, covered with abundant short pubescence of appressed woolly hairs.

Inflorescence

The flowers are assembled in small cymes of 2 or 3 flowers, inserted in the axils of the leaves. The cyme is borne by a peduncle of 2 to 6 cm.

Flower

Each flower is borne by a short pedicel of 3 to 5 mm at the base of which are 2 lanceolate bracts. The calyx is composed of 5 lanceolate sepals, 12 mm long at the tip tapered and covered with long hairs. The corolla is formed of 5 petals welded in tube enlarged at the top. It is not very open and purple in color more or less clear, sometimes white. At the top of the corolla, the petals form 5 rounded lobes whose summit is dotted with some long hairs. The corolla is 12 to 20 mm long.

Fruit

The fruits are dehiscent capsules, almost spherical, 6 mm in diameter, largely exceeded by the calyx. The top has a short tip corresponding to the style of the ovary. Each capsule contains 4 seeds.

Seed

The seeds are trigonal. The dorsal face is rounded, the two lateral faces are flat. They are 4 mm long and 3 mm wide. The tegument is dark gray and covered with a strong pubescence of stiff hairs.

https://www.gbif.org/fr/species/3680235