IV. Knotgrass (P. aviculare). Annual. Stems branching from the root, very slender and straggling, smooth. The leaves small and grassy, stipules small, white, torn-looking, red at the base. Flowers very small in the axils, pink. Stamens eight, styles three. Waste places and neglected gardens. May till October. The seeds are much esteemed by birds, and to the entomologist the fresh plant is invaluable as an almost universal food for the caterpillars of geometers.
V. Black Bindweed (P. convolvulus). Annual, with twining stems. The leaves are very similar to those of the true Convolvulus, the lobes more pointed; stipules short. Sepals green, with paler margins. Fields and wastes. July to September.
Fool's Parsley (Æthusa cynapium).
Fool's Parsley is fond of cultivated ground, and it is no unusual thing for it to make its appearance in the very garden beds that have been set apart for rearing that pot-herb for which fools are said to mistake it. It is an annual, with a spindle-shaped, fleshy root, round, hollow stem, branched, and marked with fine longitudinal lines. The leaves are smooth, compound, and bluish green in tint. The wedge-shaped leaflets are themselves pinnate, and the pinn are lobed. The flowers are small and irregular, white, grouped in small umbels, which are again gathered into large umbels of umbels.
The reader is invited to turn back to page 55, where the structure of umbelliferous flowers and fruits is more intimately described. The small umbels in Æthusa are provided with an involucre consisting of three or five little bracts, very narrow and hanging vertically. This feature will serve to distinguish Æthusa from all other umbellifers. The entire plant is evil-smelling, and said to be poisonous. It flowers during July and August, and is the only species. It gets its generic name from the Greek aitho, to burn, from its acrid character, and its specific name is a combination of Kynos, dog, and apion, parsley, which is a further note of its worthless character.
