Brassicaceae

The brassicas (Brassicaceae) or crucifers (Cruciferae) are a family of dicotyledonous angiosperms consisting of a monophyletic group with 372 genera and 4,060 accepted species. They are distributed throughout almost the entire planet, except Antarctica and some areas of the tropics. The extensive family is made up of annual, biennial and herbaceous species, many of great economic importance, both for human consumption as well as for ornamental, oilseed, and fodder uses. One of the species: Arabidopsis thaliana is considered a model organism in biological research.

Description

Species are mostly herbaceous perennials, annuals, or biennials. They are generally terrestrial plants, although a few species such as Subularia aquatica live in water. They may have a taproot (as in carrots), woody caudex with little or much branching, some with tubers or rhizomes. Stems with or without leaves (as in Caulanthus), some without stems. Leaves without stipules, alternate or rosette, simple, entire or lobed, rarely trifoliate or pinnate.

Inflorescences in racemes, corymbs or panicles. Flowers in a cross, hermaphroditic, generally actinomorphic, without bracts; calyx with 4 free sepals arranged in two dimerous whorls, sometimes with a slightly gibbous base (usually only two of them); corolla with a whorl of 4 petals, alternate with the sepals, sometimes in two groups, C 2 + 2; androecium normally with 6 stamens, arranged in two whorls: an external one with two short stamens, and an internal one with 4 long stamens (tetradynamic androecium), with basal nectaries; upper gynoecium, syncarpic, bicarpelar, with the ovary generally divided into two locules by means of a septum (also called disepimentum) originated by the growth of the placentas.

Capsular-type fruits dehiscent by means of two valves, called siliques (they can be latiseptas or angustiseptas), sometimes topped by a sterile beak.

Uses

This family includes a large part of the winter vegetables, Brassica and its cultivars, which is distributed throughout the world and consists of species with annual, biennial or perennial growth. Although some members are high in erucic acid, making them unsuitable for large doses, all members are edible; however, some taste better than others.

Evolution, phylogeny and taxonomy

Austrian botanist August von Hayek, followed by German botanist Otto Eugen Schulz, and Austrian botanist Erwin Emil Alfred Janchen-Michel von Westland, provided the first theory about the origin of the family. They believed that it had originated in the New World from the subfamily Cleomoideae of the Caparidaceae through the tribe Theylopodieae (Stanleyeae) of the Brassicaceae. This vision of the German school was shared by other authors such as the Iraqi taxonomist, naturalized American, Ihsan Ali Al-Shehbaz and the Armenian Armén Tajtadzhian. In fact, the American Thomas Nuttall had already proposed in 1834 the name Stanleyeae as a distinct and intermediate family between the Caprices and the Crucifers, which included the genera Stanleya and Warea.

Molecular studies of the Brassicas, which began to be published from the beginning of the 21st century, have clearly shown that —on the contrary— the Brassicas originated in the Old World and that they constitute a sister clade to the Brassicas. cleomaceae.

The age of the family is 37.6 (24.2 to 49.4) million years. Phylogenetic analysis suggests that the Brassicas underwent a rapid period of diversification, following the early split from the Aethionemeae tribe. The family appears to have originated in a hot and humid climate approximately 37 million years ago. The rapid radiation that occurred later was apparently caused by global cooling during the Oligocene coupled with a genomic doubling event. This event may have allowed the family to quickly adapt during that period of climate change.

Tribes

• Aethionemeae: consists of two genera and 57 species distributed mainly in the Middle East and Eastern Europe. Gender Aethionema is the largest number of species (56) and its distribution area is centered in Turkey, with some species extending east to Turkmenistan and west to Spain and Morocco.
• Camelineae: This tribe includes 12–13 genera and some 240 species that are distributed mainly in Eurasia, with some re-entryers in North America and Australia-New Zealand. The best known genre of this tribe is Arabidopsis (11 species), followed by Camelina and Capsella regarding the number of species (11 and 5, respectively).
• Boechereae: almost exclusively American since only one species, FurcakeIt grows in the eastern end of Russia. The tribe includes seven genera and approximately 110 species, most of which belong to the genus Boechera.
• Halimolobeae: includes five genera and some 40 species distributed in America, mainly in central and northern Mexico. Genres with the greatest wealth of species are Mancoa and Pennellia.

In GRIN they consider the following tribes:

• - Alyssopsidee - Anchonieae