Gourd and Daisy Families

The daisy family is one of the largest families of flowering plants: the textbook gives 19 000 species, current counts exceed 30 000 (about 1 900 genera), mostly herbs. Leaves are simple, entire or pinnately divided (wormwood). The key feature is the capitulum: many small flowers are enclosed in a common involucre and look like a single flower. Each flower has 5 fused petals, 5 stamens (anthers joined into a tube) and one pistil of two carpels; the calyx is reduced to hairs or teeth (pappus); formula: K5(hairs) C(5) A(5) G(2). Flower types: ligulate (dandelion, chicory), tubular (wormwood, the centre of the sunflower), false-ligulate (the “petals” on the edge of a sunflower), and funnel-shaped (cornflower). The fruit is an achene, often with a pappus, spread by wind. The family splits into two subfamilies: the chicory group (capitula with ligulate flowers only: dandelion, blue chicory) and the chamomile group (tubular flowers: wormwood, sunflower, Jerusalem artichoke, chrysanthemum, dahlia). In Uzbekistan 39 wormwood species are the autumn–winter feed of karakul sheep and camels. A young sunflower head follows the sun; when ripe it stays mostly facing east. 50 species of the family are in the Red Book; wormwood and others can cause hay fever (pollinosis) in many people.