“ The form of the mericarp affords valuable characters for distinguishing genera. On the outer surface of each are generally 5 ridges (primary ridges) , between which are sometimes 4 secondary ridges; oil-cavities, vittae, are often present in the intervening furrows. The fruits are variously adapted for distribution; they are sometimes thin and flat as in Hemcleum, when they are easily carried by the wind, or, as in carrot, provided with hooks. The seed contains a small embryo embedded in oily endosperm, which is usually cartilaginous in texture. ”

“ Each ovary-cell contains a single pendulous anatropous ovule with a ventral raphe and a single integument. In the development of the flower the stamens appear first, followed by the petals, the sepals and the rudiments of the carpels in succession. The flowers are rendered conspicuous by being massed into more or less dense flat-topped inflorescence's. A resemblance to the rayed heads of Compositae is suggested in the frequently larger size of the flowers on the circumference of the umbel which are often sterile and zygomorphic from the larger size of the outer petals. ”

“ Cross-pollination is rendered necessary by the flowers being generally markedly proterandrous; the stamens throughout the umbel have generally shed their pollen before the stigmas have begun to be functional even in the outer flowers. ”