Hernandiaceae

The Hernandiaceae are a family of flowering plants (angiosperms) in the order Laurales. Consisting of five genera with about 58 known species, they are distributed over the world's tropical areas, some of them widely distributed in coastal areas, but they occur from sea level to over 2000 m.
The family is closely related to the Lauraceae, and many species inhabit laurel forest habitat; they have laurel-like (lauroid) leaves. Based on morphology, chromosome numbers, geographical distribution, and phylogenetic analyses, the family is clearly divided into two groups that have been given the rank of subfamilies Gyrocarpoideae and Hernandioideae.
Overview.
The Hernandaceae are important components of tropical forests, ranging from low-lying to montane forests.
Because of the lack of worldwide knowledge about the family in general, little is known about their diversity yet. The knowledge of this family to national level, is that to be expected in countries with limited economic means with the vast majority of species indeterminate or even poorly determined. Recently described new species come from collections made in countries with limited economic means. Therefore, an increase in the study of family, at national level, is of utmost importance for the progress of the systematics of the family in general. Trees of the family Hernandiaceae predominate in the world's laurel forests and cloud forests, which occur in tropical, subtropical, and mild temperate regions of the Northern and Southern Hemispheres, highlighting the African, Indian, and Pacific Ocean islands, New Caledonia, Madagascar, and central Chile.
The main economic uses for this family are essential oils, found in many species that are important for spices and perfumes, and the hardwood of many species is a source for timber around the world. A great number of species is in danger of extinction due to overexploitation as medicinal plants or timber extraction and loss of habitat.
Taxonomy.
The family has been recognised by most taxonomists.
The APG IV system (2016) recognizes this family, and assigns it to the order Laurales in the clade Magnoliids. As circumscribed by APG, the family includes those plants that sometimes have been treated as forming the family Gyrocarpaceae.
Ecology.
The Hernandiaceae are a very important family; their species inhabit the ecosystems with monoecious, rarely dioecious, deciduous or evergreen trees, shrubs, and perennial climbing plants. The mode of dispersion is variable among the species.
Most species of genus "Hernandia" have red domes, suggesting zoochory, while "Hernandia guianensis" is hydrochorian in fresh water, and "H. nymphaeifolia" and "Gyrocarpus americanus" are hydrochorian in sea water.
The fruits are eaten by birds, passing through their digestive tracts, or are regurgitated; seeds germinate easily after. Zoocorian seeds are mostly in small fruits, desired by birds, containing many times a sticky substance coating the seed. Expelled, the seed sticks to the branch of trees and even dead bodies, or just in soil, germinating later.
Some fruits open very violently, expelling the seeds away. Others are small nuts or non-fleshy bodies (achenes) provided with hooks or filaments that stick to the fur of animals or are shaped to float in water or facilitate transport by wind.
They are distributed in the lower areas of the tropics, especially in rain forests, cloud forests, and laurel forest, although some species exist even in subtropical or arid areas; they occur from sea level to over 2000 m. Distributions in Africa and the Americas, for example, from "Gyrocarpus hababensis "and "G. americanus", relict character, appear to be due to marine transgressions in the past.
The family originated in the coastal laurel forests of Gondwana, which is the reason for its pattern of distribution. The Hernandaceae inhabit montane tropical forests, some species reaching 4000 m above sea level, but most species are more frequent in low-altitude rainforests. Some deciduous species have adapted to demanding conditions in semiarid climates, but then they tend to depend on favorable edaphic conditions, for example, perennial aquifers, periodic groundwater flows, or periodically flooded forests in sand containing hardly any nutrients.
Flowers and fruit.
The plants can have both sexes (it means, [hermaphrodite]), or monoecious. The flowers forms gropus of little flowers (inflorescences), forming in cymes in regular, ever tetracyclic or like a cycle. They present a s the non-reproductive part of the flower (perianth) with a different corolla and calyx . The corolla doesn't seems like flesh. Androecial members don't belong of the perianth and keeps in liberty of other, single-whorled. The pollen-producing reproductive organ (androecium) is only in fertile stamens. It also include a variation which form of 1–2 nectariferous glands outside the stamens, the including staminodes. Staminodes in exterior to the stamens viable to reproduction (3–5); de seppalous are opposite alternating with the inner perianth whorl (oppositisepalous). The Anthers are dehiscing constitued for longitudinal valves. The wall of anther in seed of two cotiledons only one type. The pollen grains don't have apperture, constitued by 2 cells. The ovule production are given by gynoecium of one carpel, which are reduced in number related to the perianth. The pistil is constitued by only one cell. the Gynoecium is also monomerous with only one carpel in inferior side. The placentation seems to be in an apix. The ovules form a testa from the outer integument (bitegmic), inverted so that the micropyle faces the placenta (anatropous), with two or more cell layers between the megasporophyte and the epidermal cells (crassinucellate) and pendulous. The endosperm formation is always from cells.
The fruit in some species is not fleshy with carpel indehiscent, seem to be with wings or included in an bloomed envelope derived from connate bracteoles. The seed without endosperm has two cotyledons with the appearance of flesh, oil producing, soft). The embryo is straight.
Uses.
The bark, seeds, and young leaves are purgative. The root is chewed as a remedy against eating poisonous crabs and fishes. The juice of the bark and leaves has depilatory properties. The available information on the plant parts used by Samoan healers, their modes of preparation, and application have been listed in Table 1.
Among the chemical compounds isolated from the family Hernandiaceae, the alkaloid corytuberine is the oldest known compound. Later, its derivative "O","O"-dimethylcorytuberine was reported from several "Hernandia" species, including "H. nymphaeifolia". Actinodaphnine and hernandion, were the earliest chemical compounds reported from the family hernandiaceae respectively.