Madagascar Periwinkle

A white C. roseus flower with a yellow center

Catharanthus roseus, commonly known as bright eyes, Cape periwinkle, graveyard plant, Madagascar periwinkle, old maid, pink periwinkle, rose periwinkle,^[2] is a perennial species of flowering plant in the family Apocynaceae. It is native and endemic to Madagascar, but grown elsewhere as an ornamental and medicinal plant. It is a source of the drugs vincristine and vinblastine, used to treat cancer.^[3] It was formerly included in the genus Vinca as Vinca rosea.

It has many vernacular names among which are arivotaombelona or rivotambelona, tonga, tongatse or trongatse, tsimatiririnina, and vonenina.^[4]

Synonyms

Two varieties are recognized

• Catharanthus roseus var. roseus

Synonymy for this variety

Catharanthus roseus var. angustus Steenis ex Bakhuizen f.^[5]

Catharanthus roseus var. albus G.Don^[6]

Catharanthus roseus var. occellatus G.Don^[6]

Catharanthus roseus var. nanus Markgr.^[7]

Lochnera rosea f. alba (G.Don) Woodson^[8]

Lochnera rosea var. ocellata (G.Don) Woodson

• Catharanthus roseus var. angustus (Steenis) Bakh. f.^[9]

Synonymy for this variety

Catharanthus roseus var. nanus Markgr.^[10]

Lochnera rosea var. angusta Steenis^[11]

Description

Close-up view of Catharanthus roseus in morning

Catharanthus roseus is an evergreen subshrub or herbaceous plant growing 1 m (39 in) tall. The leaves are oval to oblong, 2.5–9 cm (1.0–3.5 in) long and 1–3.5 cm (0.4–1.4 in) wide, glossy green, hairless, with a pale midrib and a short petiole 1–1.8 cm (0.4–0.7 in) long; they are arranged in opposite pairs. The flowers range from white with a yellow or red center to dark pink with a darker red center, with a basal tube 2.5–3 cm (1.0–1.2 in) long and a corolla 2–5 cm (0.8–2.0 in) diameter with five petal-like lobes. The fruit is a pair of follicles 2–4 cm (0.8–1.6 in) long and 3 mm (0.1 in) wide.^{[12][13][14][15]}

Ecology

In the wild, C. roseus is an endangered plant; the main cause of decline is habitat destruction by slash and burn agriculture.^[16] It is also, however, widely cultivated and is naturalized in subtropical and tropical areas of the world such as Australia, Bangladesh, India, Malaysia, Pakistan, and the United States.^[12] It is so well adapted to growth in Australia that it is listed as a noxious weed in Western Australia and the Australian Capital Territory,^[17] and also in parts of eastern Queensland.^[18]

Pale Pink with Red Centre Cultivar

Cultivation

As an ornamental plant, it is appreciated for its hardiness in dry and nutritionally deficient conditions, popular in subtropical gardens where temperatures never fall below 5–7 °C (41–45 °F), and as a warm-season bedding plant in temperate gardens. It is noted for its long flowering period, throughout the year in tropical conditions, and from spring to late autumn, in warm temperate climates. Full sun and well-drained soil are preferred. Numerous cultivars have been selected, for variation in flower colour (white, mauve, peach, scarlet, and reddish-orange), and also for tolerance of cooler growing conditions in temperate regions.

Notable cultivars include 'Albus' (white flowers), 'Grape Cooler' (rose-pink; cool-tolerant), the Ocellatus Group (various colours), and 'Peppermint Cooler' (white with a red centre; cool-tolerant).^[12]

In the U.S. it often remains identified as "Vinca" although botanists have shifted its identification and it often can be seen growing along roadsides in the south.

In the United Kingdom it has gained the Royal Horticultural Society's Award of Garden Merit^[19] (confirmed 2017).^[20]

Uses

Traditional

The species has long been cultivated for herbal medicine, as it can be traced back to 2600 BC Mesopotamia.^[21] In Ayurveda (Indian traditional medicine) the extracts of its roots and shoots, although poisonous, are used against several diseases. In traditional Chinese medicine, extracts from it have been used against numerous diseases, including diabetes, malaria, and Hodgkin's lymphoma.^[13] In the 1950s, vinca alkaloids, including vinblastine and vincristine, were isolated from Catharanthus roseus while screening for anti-diabetic drugs.^[22] This chance discovery led to increased research into the chemotherapeutic effects of vinblastine and vincristine. Conflict between historical indigenous use, and patent from 2001 on C. roseus-derived drugs by western pharmaceutical companies, without compensation, has led to accusations of biopiracy.^[23]

Medicinal

Vinblastine and vincristine, chemotherapy medications used to treat several types of cancers, are found in the plant^{[24][25][26][27]} and are biosynthesised from the coupling of the alkaloids catharanthine and vindoline.^[28] The newer semi-synthetic chemotherapeutic agent vinorelbine, used in the treatment of non-small-cell lung cancer,^[26][29] can be prepared either from vindoline and catharanthine^[26][30] or from the vinca alkaloid leurosine,^[31] in both cases via anhydrovinblastine.^[30] The insulin-stimulating vincoline has been isolated from the plant.^[32][33]

A periwinkle shrub

Coming in different colours

Research

Despite the medical importance and wide use, the desired alkaloids (vinblastine and vincristine) are naturally produced at very low yields. Additionally, it is complex and costly to synthesize the desired products in a lab, resulting in difficulty satisfying the demand and a need for overproduction.^[34] Treatment of the plant with phytohormones, such as salicylic acid^[35] and methyl jasmonate,^[36][37] have been shown to trigger defense mechanisms and overproduce downstream alkaloids. Studies using this technique vary in growth conditions, choice of phytohormone, and location of treatment. Concurrently, there are various efforts to map the biosynthetic pathway producing the alkaloids to find a direct path to overproduction via genetic engineering.^[38][39]

C. roseus is used in plant pathology as an experimental host for phytoplasmas.^[40] This is because it is easy to infect with a large majority of phytoplasmas, and also often has very distinctive symptoms such as phyllody and significantly reduced leaf size.^[41]

Biology

Rosinidin is the pink anthocyanidin pigment found in the flowers of C. roseus.^[42] Lochnericine is a major alkaloid in roots.^[43]

Toxicity

C. roseus can be extremely toxic if consumed orally by humans, and is cited (under its synonym Vinca rosea) in the Louisiana State Act 159. All parts of the plant are poisonous. On consumption, symptoms consist of mild stomach cramps, cardiac complications, hypotension, systematic paralysis eventually leading to death.^[44]

According to French botanist Pierre Boiteau, its poisonous properties are made known along generations of Malagasy people as a poison consumed in ordeal trials, even before the tangena fruit was used. This lent the flower one of its names vonenina, from Malagasy: vony enina meaning "flower of remorse".^[45]

Gallery

• 

  Purple Catharanthus roseus

• 

  This one was grown in Bangladesh as a ornamental plant in a flower tub in the balcony of a house

• 

  Off-white Catharanthus roseus

• 

  White Catharanthus roseus

• 

  Red Catharanthus roseus

• 

  White rosy periwinkle

• 

  Catharanthus roseus in Kerala

• 

  Purple Catharanthus roseus

• 

  Vinca From a garden at Cox's Bazar, Bangladesh

• 

  Catharanthus roseus in Ishwardi, Bangladesh

• 

  Flower bud in West Bengal, India

• 

  Garden Plant in India

• 

  Common garden plant in India

• 

  Catharanthus roseus in Pakistan

• 

  Grown in Malaysia

• 

  Flower plant raised in India temples

• 

  Fruits and seeds

• 

  Matured fruits of Madagascar Periwinkle

• 

  Immature fruits of Madagascar periwinkle

• 

  Pacifica Burgundy Halo – Madagascar Periwinkle

• 

  Red cultivar of Madagascar Periwinkle

• 

  Potted Plant in New Delhi

• 

  Anther

• 

  A fully bloomed white plant

References