Page:Manual of the New Zealand Flora.djvu/233

Rh

Herbs, very rarely climbing or shrubby, often aromatic when bruised. Stems often grooved or channelled, solid or hollow. Leaves alternate, usually much cut and divided but sometimes simple and entire; petiole dilated and sheathing at the base; stipules wanting (except in Hydrocotyle). Flowers small, hermaphrodite or occasionally polygamous, in terminal or lateral umbels which are either simple or compound. Umbels usually furnished at the base with a ring of bracts, those below the primary (or general) umbel forming the involucre, those below the secondary (or partial) ones constituting the involucel. Calyx aduate to the ovary, limb either obsolete or 5-toothed. Petals 5, inserted at the margin of an epigynous disc, the outer often larger, imbricate or valvate, usually infiexed at the tip. Stamens 5, epigynous; filaments curved inwards. Disc epigynous, often 2-lobed and confluent with the base of the styles. Ovary inferior. 2-celled; styles 2, distinct; ovules 1 in each cell, pendulous. Fruit of 2 dry indehiscent carpels cohering by their inner faces (commissure), when ripe separatmg from a filiform central axis (carpophore), from the top of which they often remain suspended for a time. Each carpel (mericarp) generally bears 5 longitudinal ridges, sometimes expanded into wings. In the spaces or furrows between the ridges, and imbedded in the pericarp, are one or more longitudinal oil-canals (vittæ). Secondary ridges are also sometimes placed between the primary ones. Seeds 1 to each carpel, pendulous; albumen abundant, horny; embryo minute, next the hilum, radicle superior.