Herbs with hollow, striate stems, sheathing petioles and flowers in umbels. Calyx adherent to the ovary, limb entire or 5-toothed. Petals 5, usually inflected at the point imbricate in aestivation. Stamens 5, alternate with the petals, and inserted with them on the disk. Ovaries 2-carpeled, surmounted by the fleshy disk which bears the petals and stamens. Styles 2, distinct or united at their thickened bases. Stigmas simple. Fruit a cremocarp (§ 557), consisting of 2 coherent achenia called mericarps which separate along the middle space, which is called the commissure. Carpophore, the slender, simple or forked axis attached to and supporting the mericarps at top, inclosed between them at the commissure. Ribs - 5 ridges traversing each mericarp lengthwise, and often 4 intermediate or secondary ones, some, all, or none of them winged, Viltae - little tubular receptacles of colored volatile oil imbedded in the substance of the pericarp, just beneath the intervals of the ribs, and also sometimes in the face of the commissure. Embryo in the base of abundant, horny albumen. (IIlust. in figs. 25, 27, 102, 131,
135, 163, 207, 297, 433.)
Genera 270, species 1500 or more. A large and well defined natural order, native of damp places, waysides, groves, etc., in the cool parts of the world. Very few are found in tropical countries, except upon the mountains.
Properties, aromatic, stimulant and carminative, depending; upon a volatile oil residing; in the vittae of the fruit, in the roots etc. The herbage is frequently pervaded by an acrid, narcotic principle, rendering it very poisonous. Of this nature is the Conium maculatum (Hemlock), Cicuta virosa, aethusa Cynapium (Fool's Parsley), besides many others which have at least a suspicious character. But the fruit is never poisonous, and is usually stimulant and aromatic, as Caraway, Anise, Dill, Coriander. etc. Even the roots and herbage of other species are whole-Bome and nutritive, as the Carrot. Parsnip, Sweet Cicely, Celery, and Archangelica. The gum resin asafaetida exudes from incisions on the Ferula of Persia. The Gum Galbanum is the product of Galbanum officinale, an Indian species. The genera of the Umhelliferae; are often best defined by characters founded upon the number and development of the ribs, the presence or absence of the vittae, and the form of the albumen, particularly at the commissure. These parts, therefore, minute as they are, will require the especial attention of the student.
De Candolle subdivided the Umbelworts into sections, depending upon the form of the albumen and seed, whether (1.) flat on the inner face, or (2.) convolute at the sides, or (3.) involute at the ends. This arrangement is often impracticable as a step in the