Nectandra Membranacea

''Nectandra'' is a genus of plant in the family Lauraceae. They are primarily Neotropical, with ''Nectandra coriacea'' being the only species reaching the southernmost United States. They have fruit with various medical effects. Sweetwood is a common name for some plants in this genus.

Description

They are trees and bushes, hermaphrodites. The leaves are alternate, entire, glabrous or pubescent pinnatinervias with longitudinal grooves. Simple, alternate, petiole 0.9 to 2.2 cm in length canalicular limbo 11 to 28 cm long and 5 to 11 cm wide, with 16–28 secondary veins; base acute decurrent and revolute, entire, apex elliptically shaped, green dark, and very oblique secondary veins visible on the underside. Terminal buds are whitish. The inflorescences are pseudo-axillary and paniculate, the last divisions cimosas, mostly somewhat pubescent, the flowers are small, rarely more than 1 cm in diameter, and white or greenish tepals equal. The fruit is an ovoid, fleshy drupe with a reddish-pink dome, green when immature and black when ripe.

Ecology

A neotropical genus with 114 species, Nectandra is similar to ''Ocotea'', to which it is closely related. The most characteristic distinguishing features are the position of the locules in the anther (in an arc in ''Nectandra'' and two rows in ''Ocotea''); papillose pubescence is present; the ''Nectandra'' petals are fused at the base itself and fall as a unit in the old flowers; they are free in ''Nectandra'' but fall individually in Ocotea.

Medium trees reach 60 cm in diameter and 25 m in height with straight, slender, cylindrical boles with low low and thin protuberances at the base. The various species are located in the middle stratum of forests. Many species are used as timber.

The family Lauraceae was part of the Gondwanaland flora, and many of its genera migrated to South America via Antarctica on ocean landbridges during the Paleocene era. There, they spread over most of the continent. When the North American and South American tectonic plates joined in the late Neogene, volcanic mountains started creating island chains, later forming the Meso-American landbridge.

Pliocene elevation created new habitats for speciation. While some genera died out in increasingly xerophytic Africa, starting with the freezing of Antarctica about 20 million years ago and the formation of the Benguela current, others, like ''Beilschmiedia'' and ''Nectandra'', which also reached south and meso-America, are still surviving today in Africa in several species. The genus ''Persea'', however, died out in Africa, except for ''Persea indica'', surviving in the fog-shrouded mountains of the Canary Islands, which, with Madagascar, constitutes Africa's Laurel forest plant refugia. In Meso-America, the genus ''Nectandra'' proliferated into new species, and some of its berries constitute a valuable food supply for the quetzal bird that lives in the montane rainforests. Since this habitat is constantly threatened by encroaching agriculture, the laurel forest animal and plant species have already become rare in many of its former habitats and are threatened by habitat loss.

The quetzal's favorite fruits are berries of relatives of ''Nectandra umbrosa''. Their differing maturing times in the Cloud forest determine the migratory movements of the quetzals to differing elevation levels in the forests. With a gape width of 21 mm, the quetzal swallows the small berries (aquacatillos) whole, which he catches while flying through the lower canopy of the tree, and then regurgitates the seed within 100 meters from the tree. Wheelwright, in 1983, observed that parent quetzals take far fewer time intervals to deliver fruits to the young brood than insects or lizards, reflecting the ease of procuring fruits, as opposed to capturing animal prey. Since the young are fed exclusively berries in the first two weeks after hatching, these berries must be highly nutritional. Usually, only the total percentage of water, sugar, nitrogen, crude fats and carbohydrates are reported by ornithologists.

Medical use

Plants from this genus have been used to treat several human clinical disorders. It has been demonstrated that Nectandra plants have potential for analgesic, anti-inflammatory, febrifuge, energetic, and hypotensive activities. ''Nectandra'' has also been investigated as a possible antitumoral agent, and the presence of neolignans suggests its potential use as a source of chemotherapeutics. Crude extracts of ''Nectandra'' contain alkaloids and lignans, berberine and sipirine.

Some authors have postulated that tannins play important roles as antioxidant compounds in scavenging free radicals. It is reported that an extract of ''N. salicifolia'' has potent relaxant activity on vascular smooth muscle. Researchers around the entire world agree that extensive pre-clinical studies on herbal medicine are important and urgent, especially high-quality clinical and pre-clinical trials.

In pre-Columbian Peru the seeds, called ''amala'' in Spanish, were used as a muscle relaxant. In sites of the Sican culture, collections of the seeds have been associated with human sacrifice, and used to incapacitate victims prior to being killed.

Selected species

''Nectandra'' contains approximately 120 species, including the following:

References

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Lauraceae genera
Flora of Northern America
Flora of Southern America
Taxonomy articles created by Polbot
Taxa named by Christen Friis Rottbøll
Flora of the Neotropical realm