_Herbs, with small flowers in umbels (or rarely in heads), the calyx entirely adhering to the 2-celled and 2-ovuled ovary, the 5 petals and 5 stamens inserted on the disk that crowns the ovary and surrounds the base of the 2 styles. Fruit consisting of 2 seed-like dry carpels._ Limb of the calyx obsolete, or a mere 5-toothed border. Petals either imbricated in the bud or valvate with the point inflexed. The two carpels (called _mericarps_) cohering by their inner face (the _commissure_), when ripe separating from each other and usually suspended from the summit of a slender prolongation of the axis (_carpophore_); each carpel marked lengthwise with _5 primary ribs_, and often with 4 intermediate (_secondary_) ones; in the _interstices_ or _intervals_ between them are commonly lodged the oil-tubes (_vittæ_), which are longitudinal canals in the substance of the fruit, containing aromatic oil. (These are best seen in slices made across the fruit.) Seed suspended from the summit of the cell, anatropous, with a minute embryo in hard albumen.--Stems usually hollow. Leaves alternate, mostly compound, the petioles expanded or sheathing at base, rarely with true stipules. Umbels usually compound, in which case the secondary ones are termed _umbellets_; the whorl of bracts which often subtends the general umbel is the _involucre_, and those of the umbellets the _involucels_. The base of the styles is frequently thickened and cushion-like, and called the _stylopodium_. In many the flowers are _dichogamous_, i.e. the styles are protruded from the bud some time before the anthers develop,--an arrangement for cross-fertilization.--A large family, some of the plants innocent and aromatic, others with very poisonous (acrid-narcotic) properties. The flowers are much alike in all, and the fruits, inflorescence, etc., likewise exhibit comparatively small diversity. The family is consequently difficult for the young student. I. Fruit with the secondary ribs the most prominent, winged and armed with barbed or hooked prickles, the primary ribs filiform and bristly. 1. Daucus. Calyx-teeth obsolete. Fruit flattened dorsally. Seed-face flat. 2. Caucalis. Calyx-teeth prominent. Fruit flattened laterally. Seed-face deeply sulcate. II. Fruit with primary ribs only (hence but 3 dorsal ones on each carpel). [*] Fruit strongly flattened dorsally, with the lateral ribs prominently winged. [+] Caulescent branching plants, with white flowers. [++] Lateral wings distinct; oil-tubes usually more than one in the intervals. 3. Angelica. Stylopodium mostly depressed, but the disk prominent and crenulate. Dorsal ribs strong. Stout perennials, with mostly coarsely divided leaves. 4. Conioselinum. Stylopodium slightly conical. Dorsal ribs prominent. Tall slender glabrous perennial; leaves thin, finely pinnately compound. [++][++] Lateral wings closely contiguous; oil-tubes solitary; stylopodium thick-conical.