Bougainvillea

Bougainvillea is a hardy ornamental viny shrub of the four o’clock family or Nycataginaceae, which originated in subtropical and tropical South America. Bougainvillea was first classified in Rio de Janeiro in 1768 by the French botanist Philibert Commercon (1727-1773), who named the plant after the navigator Louis-Antoine de Bougainville (1729-1811), with whom he had served in the French navy. There are now around 34 genera. However, there seems to be no definitive agreement on the number of bougainvillea species in existence, with estimates ranging from 4 to 350. This lack of accord is due to frequent hybridization in the genus in India and Malaysia, which makes the identification of individual species extremely difficult. Bougainvillea grows across the globe in areas with warm climates. Although some species will tolerate cooler environments and high altitudes, with Bougainvillea spectabilis the most cold-tolerant of all bougainvilleas, bougainvillea cannot survive temperatures much below freezing and should be planted in areas that do not suffer from frost. In cooler areas bougainvillea can be raised as a houseplant or in a conservatory.

Attributes

Bougainvillea is a quick-growing impenetrable hedge the height of which varies depending on the species or cultivar, with a dwarf species called Bougainvillea Temple Fire available. The stem of the bougainvillea has hook-like spines, which allow the plant to climb over rough surfaces. While the spines allow for scrambling over coarse- textured surfaces, wires, trellises, or other supports may be needed for bougainvillea to spread over the exterior of smooth walls or arbors. Bougainvillea has round to oval, alternate, opposite leaves, which can be evergreen or semievergreen. The most striking aspect of the bougainvillea is the brightly hued bracts, which are petal-like and are most often to be found in

Bougainvillea (Wilm Ihlenfeld/Dreamstime.com)

shades of purple, red, yellow, orange, pink, and white with the latter tending to be particularly tender. The tissue-paper-like texture of the bracts has led to the

bougainvillea gaining the soubriquet “the paper flower.” In some plants, bracts of two colors can be found on the same shrub, while some cultivars see the bracts change color with age thus giving the appearance of several colors growing together. The actual flower of the bougainvillea is a small, creamy-colored tube-like structure attached to the base of the bracts.

Species and Hybrids

There are three main horticultural species: Bougainvillea spectabilis, Bougainvillea peruviana, and Bougainvillea glabra. From these, three major hybrid groups have emerged Bougainvillea X buttiana (a hybrid of Bougainvillea peruviana and Bougainvillea glabra), Bougainvillea X spectoperuviana (a hybrid of Bougainvillea peruviana and Bougainvillea glabra), and Bougainvillea X spectoglabra (a hybrid of Bougainvillea spectabilis and Bougainvillea glabra). The horticultural cultivars have originated from both natural and artificial hybrids, and among the bud sports are some variegated and double-bract sports. One frequently grown species of bougainvillea is Bougainvillea X buttiana Holttum and Standley. This is made readily distinguishable by its vicious spines of up to two inches in length and shrubby habit. The species scrambles and can climb into trees. The plant has white flowers surrounded by red, purple, white, or orange bracts, and the leaves are a dull green shade and ovate. This species flowers year-round, with the flowers borne either in one to three clusters of three each or in panicles on top of a stalk that develops into a spine. Each flower is connected to a bract. Another frequently grown bougainvillea is Bougainvillea glabra Choisy. Like Bougainvillea X buttiana Holttum and Standley, Bougainvillea glabra Choisy has sharp spines and dull ovate leaves. The bracts of Bougainvillea glabra Choisy are magenta. Bougainvillea glabra Choisy is occasionally misidentified as Bougainvillea X buttiana, but the two plants differ in that the leaf tip of the latter has leaves with a duller upper surface and, rather than the attenuated leaf tip of Bougainvillea glabra Choisy, the leaves of Bougainvillea X buttiana have an acute tip. Bougainvillea glabra and Bougainvillea X buttiana can hybridize, leading to greater confusion as to nomenclature.

Cultivation

Bougainvillea can be grown as a shrub, a specimen plant climber, or a climber, though the object the bougainvillea will scramble over must be sufficiently strong to stand the weight of a plant, which may grow to 65 feet tall and therefore weigh a considerable amount. In areas of India, such as Bangalore, bougainvillea is trained to grow into a ground-covering mound. This is achieved by pegging the stems of the plant to the ground as it grows and removing all upward-growing branches. However, this will diminish the colorful impact of the plant as the frequent cutting necessary to achieve the lateral spread removes flowering growth. The dense foliage of both Bougainvillea X buttiana and Bougainvillea glabra makes both species ideally suited to the creation of topiary shapes.

Bougainvillea prefers full sun and will grow in any soil that is not saturated with water. Once the plant is established, it will form a deep root system and will need very little watering or care in general. Bougainvillea grown in full sun produce the best colors as the plant does not enjoy shade. Bougainvillea can be propagated by budding, by air or ground layering, or from hardwood leafy cuttings of around eight inches in length, the recommended method for Bougainvillea X buttiana. Tip cuttings may also be used for the propagation of species such as Bougainvillea cypheri. Bougainvillea infrequently bears a single-seed fruit known as an anthocarp. Bougainvillea glabra new cultivars and hybrids may be raised from seeds.

Victoria Williams

Further Reading

Mathias, Mildred E., ed. Flowering Plants in the Landscape. Berkeley: University of California Press, 1982.

Singh, Gurcharan, and Amitabha Mukhopadhyay. Floriculture in India. Mumbai, India: Allied, 2004.

Spencer, Roger. Horticultural Flora of South-Eastern Australia. Vol. 2, Flowering Plants. Sydney: UNSW Press, 2004.

Tenenbaum, Frances, ed. Taylor’s Encyclopedia of Garden Plants. New York: Houghton Mifflin, 2003.

Whistler, W. Arthur. Tropical Ornamentals: A Guide. Portland, OR: Timber Press, 2000.

 
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