Coldenia procumbens (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Coldenia procumbens L.

Protologue: Sp. pl. 1: 125 (1753).

Family: Boraginaceae

Chromosome number: 2n= unknown

• Philippines: tapiasin, oreganong-lalaki (Tagalog), tabatabokol (Iloko)
• Thailand: yaa teentukkae (Suphan Buri, Phitsanulok), yaa teentukto, yaa tupto (Chiang Mai)
• Vietnam: cáp diền.

C. procumbens is widespread in tropical and subtropical Africa, Asia and Australia. In Asia, it has been recorded from India, Sri Lanka, Burma (Myanmar), Indo-China, Taiwan, Hainan, Thailand, Peninsular Malaysia, Java, Borneo, the Philippines, the Lesser Sunda Islands, the Moluccas and New Guinea.

In the Philippines C. procumbens leaves are used as a poultice to mature abscesses. In India, they are applied to rheumatic swellings.

In a general pharmacological screening with mice and rats, an ethanolic extract of whole C. procumbens plants produced depression of the central nervous system and significant prolongation of the pentobarbital-induced sleeping time. It exhibited significant analgesic effects, but had no anticonvulsant effects, did not alter body temperature, and did not abolish conditioned avoidance responses. The acetone, ethanol and water extracts of dried aerial parts of C. procumbens showed weak angiotensin-converting enzyme inhibition.

A small, annual, prostrate herb with dorsiventrally compressed, ascendingly branched stems up to 50 cm long, greyish hairy. Leaves alternate, simple, asymmetric, oblong or obovate, 0.5-3 cm × 0.5-1.5 cm, crenate-dentate to lobulate, with 4-6 pairs of veins impressed above, prominent beneath; petiole up to 0.5 cm long; stipules absent. Flowers arranged between the leaves, bisexual, 4-merous, tiny, subsessile; calyx c. 1.5 mm long, slightly accrescent in fruit; corolla up to 2 mm long, with cylindrical tube and diminute lobes, white; stamens inserted about the middle of the corolla tube, included; ovary superior, glandular villous, style bifid nearly to the base. Fruit dividing initially into 2 halves, later each half into 2 one-seeded nutlets; nutlets sharply angulate ventrally, with a distinct beak.

The mesocarp (middle layer of the nutlet wall) is thick and corky at the dorsal side. This enables dispersal of the nutlets by water.

Coldenia is a monotypic genus. Several American species have been included, but these have now been referred to the genus Tiquilia , which comprises perennial herbs and subshrubs with symmetric leaves and 5-merous flowers.

C. procumbens is often found in seasonally flooded locations, e.g. on dry rice fields, where it is a common weed, but it can also withstand severe drought.

C. procumbens is sufficiently widely distributed and adapted to anthropogenic habitats to ensure its survival in the long run. It is sometimes even considered a potentially serious weed, e.g. in vegetable crops in the Andaman and Nicobar Islands.

The scanty information available on the pharmacological properties of C. procumbens seems to warrant more research because it indicates that the plant possesses analgesic properties.

247, 760, 768.

117, 881.

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N.O. Aguilar