Malvaceae

The malvaceae (Malvaceae) are a family of plants belonging to the order Malvales. Gather herbaceous, woody plants or shrubs (more common in hot countries). Includes, among others, Hibiscus, mallows and the cotton plant (Gossypium).

Description

Malvaceae have alternate leaves, commonly palmate-shaped, with three main veins that arise from the base of the leaf blade and, in addition, they have small, deciduous stipules. Star-shaped hairs are found in the vegetative organs and mucilage channels are found in the tissues.

The flowers are conspicuous, entomophilous, hermaphrodite, actinomorphic and grouped in inflorescences; the calyx has five sepals, free or welded at the base, frequently accompanied by an epicalice or calculus (hypsophilic). Usually, the calyx bears nectaries composed of glandular trichomes. The corolla presents five free petals with a very long nail, the blade welded or bifid. The androecium is composed of numerous stamens, typically with the filaments welded together in a staminal tube (called the staminal column) that surrounds the styles, and each stamen with a single theca. The pollen is spiny, the ovary gynoecium super, formed by five or more carpels and 5 styles. The number of ovules is variable and the axillary placentation. The fruits are schizocarpic or capsular. The seeds present characteristic fatty acids, which conjugate the cyclopropenyl anion.

Diotomical keys for the main European genres

• 1. Fruit in capsule (botanical) loclicida, polysperma (locules 1-polispermos)  2
• 1. Fruit in schizocarpo (mericarpos 1-polispermos)  4
• 2. Epicáliz: 3 pieces; cupuliform cup, truncated or 5-dented, seldom 5-lobed; usually coated seeds of much longer hairs than they Gossypium
• 2. Epicáliz: 5-20 pieces; 5-lobed or dented chalice; glabra seeds or with shorter hairs than them  3
• 3. Subgloboso-depressed capsule, 5-lobade; monospermos Kosteletzkya
• 3. Balloonous or ovoid capsule, not muddled; 2-Polls Hibiscus
• 4. Non-existent epicaliz ▪ 5
• 4. Epicáliz present  6
• 5. Carpets with 1 seminal rudiment; mericarpos monospermos Sida
• 5. Folds with 3-9 seminal rudiments; mericarpos: (1)2-3(9) seeds Abutilon
• 6. Pieces of the epicaliz welded at least in the /2005 base 7
• 6. Pieces of the epicaliz free  9
• 7. Epicáliz: 3 pieces broadly ovated Washing machine
• 7. Epicáliz: 6-12 narrow pieces, from linear to oblongo-triangular roga 8
• 8. Pétalos: 3-6 cm; 5-angulate staminal tube, glabro; bilocular mericarpos, grooves and slightly winged on the back  Alcea
• 8. Pétalos 1-3 cm; cylindrical staminal tube, hairy at the base, unilocular mericarpos, planes and apteros on the back Althaea
• 9. Mericarpos in several verticils; schizocarpo globoso Malope
• 9. Mericarpos in a single verticyl; schizocarpo discoideo  10
• 10. Terminal estigmas, capitados; mericarpos with 2(3) seeds  Modiola
• 10. Estigmas decurrent, elargados; mericarpos monospermos  11
• 11. Pieces of the epicáliz setáceas; mericarpos inflated in maturity  Malvella
• 11. Pieces of linear epicaliz to lanceolates; non-inflated mericarpos  Malva

Taxonomy

Recent molecular studies have led the angiosperm phylogeny group to expand the family to 243 genera and more than 4,225 species; The extended family includes the genera that previously belonged to the old families Bombacaceae, Sterculiaceae and Tiliaceae, so well-known genera such as Tilia, Ceiba remained as belonging to this family. >, Adansonia (baobabs) and Ochroma, now forming simple subfamilies:

Malvoideae

Malvoideas include 78 genera and some 1670 species. This subfamily is made up of several tribes that constitute the Malvaceae in the strict sense, in addition to Matisiae and Fremontodendreae, and possibly also Ochromeae, Fremontodendreae and Septotheca. The division of Malvaceae in a narrow sense into tribes has historically been unstable and a definitive classification has not yet been reached. The current division includes Malveae (Malva, Abutilon, Sida and related genera), Gossypieae (the genus that includes cotton, Gossypium, and related genera), Hibisceae (Hibiscus, Pavonia, Kydia and related genera). Matisieae is a group, previously classified within the Bombacaceae, with a Neotropical distribution. Fremontodendreae is made up of two genera from Guatemala, Mexico, and California, which had previously been treated as Bombacaceae or Sterculiaceae. The genera Pentaplaris, Uladendron, Camptostemon, Lagunaria, Howittia, Alyogyne and Jumelleanthus are included in the Malvoideae but have not yet been assigned to any tribe.

The genera with the highest species richness are Hibiscus (580), Sida (200), Abutilon (100), Nototriche (100), Cristaria (75) and Gossypium (40).

Bombacoideae

The Bombacoids include 16 genera and about 120 species from tropical regions, especially the Americas and Africa. The Bombacoids subfamily is composed of the remaining genera of the Bombacaceae after the Matisieae and Durioneae tribes were transferred to the malvoideas and helicteroideas, respectively. For this reason, in its current circumscription the subfamily is basically represented by the Adansonieae tribe, which includes the genera Adansonia, Bombax, Chorisia, among others. The genera with the highest species richness are Pachira (24) and Pseudobombax (20).

Sterculioideae

The sterculioids are made up of 12 genera and about 430 species of pantropical distribution. This subfamily was considered a separate family from Malvaceae, called Sterculiaceae, in other angiosperm classification systems. Species in this subfamily are characterized by petalless flowers (apétalas), lacking an epicalyx, and the presence of a calyx. fleshy, usually petaloid and gamosepalous. They do not have staminoids either, but they do have a monadelpha staminal column (that is, with all the stamens joined together) and gynoeces and apocarpic fruits, that is, with separated carpels. The flowers are typically monoecious: there are both male and female flowers on the same plant.

In such a way that the family, thus expanded, is now divided into 9 subfamilies:

• See also the annex on the currently admitted genus of malices.