Articles

Indigofera hirsuta L.

Indigofera hirsuta L.

Family

Leguminosae

Synonyms

Indigofera indica Miller, Indigofera ferruginea Schum. & Thonn., Indigofera angustifo­lia Blanco.

Vernacular Names

Malaysia Cermai burong.
English Hairy indigo.
American Rough hairy indigo.
Indone­sia Tom-toman, jukut lulut (Java), tebawang am­jak (Sulawesi).
Philip­pines

Tayom (Iloko), tagum (Bisaya), tina-tinaan (Tagalog).

Papua New Guinea Tildjil, wiereka.
Thailand

Khram-khon (northern).

Vietnam

C[aa]y c[or] ch[af]m, c[aa]y s[uj]c s[aj]c ma, ch[af]m l[oo]ng.

French Indigotier herisse.

Geographical Distributions

Indigofera hirsu­ta is native to Asia and Africa. It was cultivated as a green manure in Bogor in the 19th Century and was first tried as such in Malaysia in 1913. It was introduced into the United States in 1908 and proved suitable for cultivation in the coastal re­gions of Florida and Texas. It is now cultivated throughout the tropics.

Description

Indigofera hirsuta is an annual herb or subshrub, up to 1.5 m tall, covered with conspicuous brown hairs, which are biramous and spreading with very un­equally long arms and looks almost simple. The branch­es are erect, striate and become woody at maturi­ty.

The leaves are imparipinnate. The stipules 10-12 mm long are narrowly trian­gular to linear. The petiole is 2-5 cm long. The rachis is up to 9 cm long. The stipels are 1-2 mm while the peti­olule is 1.5-3 mm long. There are 5-11 oppositely arranged leaflets which are ellip­tical to obovate. The terminal ones measure 2.5-3.5(-6) cm x 1-2(-3) cm while the lateral ones are 1.5-3 cm x 0.7-1.5 cm. The base is wedge-shaped, rounded at apex, mucronate, hairy on both surfaces, with distinct veins and brown main vein.

The inflorescence is a densely flowered raceme, and measures (3-)10-30 cm long. The bracts are linear-triangular, about 4 mm long and caducous. The peduncle is 3 cm or longer whereas the pedicel is about 2 mm long. The flowers are up to 6 mm long. The sepal is about 4 mm long, and with stiff brown hairs that are di­vided almost to the base into linear and setaceous lobes. The petal is red to pink. The upper part of petal is elliptical, measuring 4-5 mm x 2-2.5 mm, emarginate at apex and it is white pubes­cent outside. The wings measure 4-5 mm x 1.5 mm hairy at the up­per margin. The keel measures 4-5 mm x 1.2-1.5 mm where the upper margin is with hairs and lateral pocket of 0.7 mm long. The staminal tube is 4.5 mm long while the anthers are 0.4 mm long. The ovary is hairy with 6-9 ovules.

The fruit is a reflexed, straight pod which is rounded to tetragonal in cross-sec­tion. It measures 1-2 cm x 1-2.5 mm, with well-developed su­tures and with long spreading hairs. It is dehiscent, (4-)6-9-seeded and with blotched endocarp. The seed 1 mm long is cuboid, brown and distinctly pitted.

Ecology / Cultivation

Indigofera hirsuta occurs as a weed in cultivat­ed and waste areas, in grasslands, savannas, dry and deciduous forests, on river banks and beaches, at 0-1500 m altitude. It requires an annual rain­fall of 900-2500 mm and an annual mean temper­ature of 15-28°C. It does not tolerate frost. A dry season stimulates flowering and seed production. Although generally fairly tolerant to shade, growth under heavy shade in an established stand of pine trees in Costa Rica was poor. I. hirsuta is tolerant to poor soil conditions, and grows well on moderately poor, sandy soils with low pH, and on slopes. It requires moderately to well-drained soils with a pH of 5-8 and is intolerant of waterlogging.

Line Drawing / Photograph

Indigofera_hirsuta

References

  1. Plant Resources of South-East Asia No.11: Auxiliary plants.