Chocolate, cotton, okra and durian are all members of the mallow family
A single plant family gives us chocolate from cacao, the cotton in our shirts, okra for gumbo, cola nuts, baobab fruit and the notoriously pungent durian. The mallows, Malvaceae, hold an estimated 4,225 species, and botanists spent years arguing over where the family's edges should even be drawn.
The family spans roughly 244 genera. Hibiscus alone accounts for 434 species, followed by groups such as Pavonia and Sida. Garden favourites include hollyhock and the rose of Sharon, and lime or linden trees belong here too. Most members are herbs or shrubs, though there are trees and climbing vines, and baobab stems in one subfamily bristle with thick prickles.
The traditional mallow family was a tidy, natural group. Genetic studies then showed that three neighbouring families, including the one that once held baobabs and another that held linden trees, did not form natural groups on their own. The solution was to fold them all into an enlarged Malvaceae of nine subfamilies. How those subfamilies relate stayed murky until a 2021 study used genomic data from all nine to produce a fully resolved family tree.
Older definitions relied on traits such as leaf teeth each tipped by a vein, stems with mucilage canals and star-shaped hairs, but not every member had them. Researchers later found firmer shared features: tile cells in the wood, nectaries made of densely packed glandular hairs, usually on the sepals, and a branching flower arrangement called the bicolor unit, named after the cacao relative Theobroma bicolor in which it was first described. Many flowers have five sepals, five petals and stamens fused into a tube around the pistil, and they dodge self-pollination by releasing pollen before their own stigmas are ready.
Most species rely on insects, and some bees in the tribe Emphorini specialise on them. Not every member is welcome: velvetleaf, Abutilon theophrasti, is an agricultural weed. The name mallow comes from Latin malva, which also gave English the colour mauve and shares roots with mulukhiyah, the leafy dish of the Arab world.
Source: Malvaceae
