Catharanthus roseus (L.) G. Don

Catharanthus roseus (L.) G. Don

Family

Apocynaceae

Synonyms

Vinca rosea L., Lochnera rosea (L.) Reinchenb. ex Endl.

Vernacular Names

Malaysia

Kemunting china, rumput jalang, tahi ayam (Peninsular).

English

Madagascar periwinkle.

Indonesia

Bunga serdadu, kembang tembaga, tapak dara (General).

Philippines

Chichirica (Sp), kantotai, amnias (Tagalog).

Thailand

Nom in (Surat Thani), phakpot bok (Northern), phaengphuai bok (Bangkok).

Vietnam

C[aa]y b[oo]ng d[uwf]a, d[uwf]a c[aj]n, hoa h[ar]id[awf]ng.

Geographical Distributions

Catharanthus roseus belongs to a small genus of 8 species, all originating from Madagascar except for Catharanthus pusillus (Murr.) G. Don, which is restricted to India and Sri Lanka. For centuries, Madagascar periwinkle has been cultivated as an ornament throughout the tropics and occasionally in the subtropics; it has become naturalised in many regions. It was brought into cultivation in the first half of the 18th Century in Paris, from seeds collected in Madagascar, and was later distributed from European botanical gardens to the tropics as an ornament.

Description

Catharanthus roseus is an erect or decumbent, deciduous undershrub up to 100(-200) cm tall and usually with white latex. The roots are up to 70 cm long while the stems are often woody at base.

The leaves are decussate, simple, elliptical to obovate or narrowly obovate, measuring (3-)4-9 cm x (1-)1.5-3.5 cm, herbaceous to thinly leathery, wedge-shaped and sometimes oblique at base, apex is obtuse or acute with a mucronate tip, entire, glossy green above and pale green below, hairy to hairless on both sides, with 7-11 secondary veins on both sides of midrib and more or less conspicuous while the tertiary venation is inconspicuous. The petiole is (0.1-)0.3-1 cm long and with a fringe of colleters in the axil. True stipules are absent.

The 1-2-flowered inflorescence is terminal but apparently lateral because of alternating development of one of the axillary buds of the apical leaf pair. The flowers are actinomorphic, bisexual, 5-merous and subsessile. The sepals are slightly connate at base, measuring (2-)3-5 mm x 1-1.5 mm and green. The petal is salver-shaped, pink, rose-purple or white with a purple, red, pink, pale yellow or white centre with tube 2-3 cm long and widening near the top, laxly hairy to becoming hairless outside, with a dense ring of hairs in the throat and with a silky ring of hairs lower down the tube, with broadly obovate lobes, measuring 1-2(-3) cm long, mucronate at apex, smooth, spreading and bud overlapping to the left. The stamens are included in the petal tube, which are inserted just below the petal throat, with very short filaments, free anthers and introrse. The ovary is superior, consisting of 2 very narrowly oblong carpels at base, with filiform style, a cylindrical pistil head at the base with a reflexed hyaline frill ('petticoat') and with rings of woolly hairs at the base and apex. The stigma is hairless while the disk is composed of 2 glands and often longer than the ovary.

The fruit is composed of 2 cylindrical and acute follicles which are 1-4 cm long, striate, laxly hairy to hairless, green, dehiscent at adaxial side and many-seeded. The seeds are oblong, measure 1-2 mm long, with rugose testa and lateral hilum and black. Cotyledons are flat and slightly shorter than the radicle while the endosperm is scanty.

Ecology / Cultivation

Catharanthus roseus often occurs in sandy locations along the coast, but also inland on river banks, in savanna vegetation and in dry waste places and roadsides, sometimes in open forests or scrubs, usually on sandy soils, but sometimes also on rocky soils. It is highly salt-tolerant, and is mostly found near sea level, but occasionally up to 1500 m altitude. It can withstand drought well but not severe heat. Under severe water stress, the alkaloid content of mature leaves was found to double, but it did not change in stems and immature leaves and it decreased in roots.

Line Drawing / Photograph

Catharanthus_roseus

References

1.       Plant Resources of South-East Asia No.12(1): Medicinal and poisonous plants 1.