Fabales

Fabales is an order of plants of the class Magnoliopsida, subclass Rosidae, with worldwide distribution (more common in tropical areas) and with a high altitudinal distribution. Between 16,000 and 18,000 species (one of the largest orders), with great economic importance, as food: fruits, seeds or the entire plant (fodder); medicinal; industrial: gums, oils and perfumes; ornamental; etc.

The Fabaceae, as the third largest plant family in the world, contain most of the diversity of the Fabales, the other families constituting a comparatively small part of the order's diversity. Research in the order focuses mainly on the Fabaceae, due in part to their great biological diversity and their importance as food plants. The Polygalaceae are fairly well-researched among plant families, partly due to the great diversity of the genus Polygala, and other members of the family are food plants for several species of Lepidoptera (butterflies and moths). While taxonomists using molecular phylogenetic techniques find strong support for the order, questions remain about the morphological relationships of the Quillajaceae and Surianaceae to the rest of the order, due in part to limited research on these families.

Features

Very homogeneous group. Actinomorphic or zygomorphic flowers (there is a tendency to zygomorphy), hermaphrodites, pentamerous, with a tendency to reduce the number of stamens, with one carpel. Leaves generally compound and stipulated. Fruit generally dry and dehiscent by two sutures (carpel nerve and suture): legume.

The flowers may be solitary or grouped in the leaf axils. The inflorescences, when present, are of various types, simple or variously branched. The flowers are usually bisexual, but unisexual flowers appear sporadically throughout the family. Some legumes produce two types of flowers, commonly on the same plant. Typicals have conspicuous petals that spread open to allow cross-pollination (in some, an obligatory propagation mechanism); in others, all parts are reduced and the petals do not open, forcing self-pollination. In some flowers, the sepals are usually partially fused, and the five petals alternate their position with the sepals. There are normally around 10 stamens. The stamens may remain free or be fused into a single tubular structure (monadelphus) or a group of nine united stamens with a free stamen above.

The formation of nitrogen-fixing nodules is frequent.

Biotypes

Trees, shrubs and herbs (the latter two more common in temperate zones). Related to Rosaceae and Saxifragaceae.

Three groups, which are usually distributed in two different ways:

• Three subfamilies: Faboideae, Mimosaceae and Caesalpiniaceae

Distribution and diversity

This order has a cosmopolitan distribution, although it is more frequent in tropical areas, and has a large altitudinal distribution. The subfamily Papilionoideae family (Faboideae) Fabaceae, although present in all major biomes on earth, was concentrated in the temperate climate regions of the northern hemisphere.

The order contains between 21,000 and 23,000 species (it is one of the largest orders of flowering plants), including multiple species of great economic importance. The members of this order, in particular the family Fabaceae, are used as plants for human consumption (through the use of fruits, seeds or the whole plant), as medicinal plants, as ornamentals, for forestry (production of wood and soil protection) and for industrial use (gum, oil and perfume production).