This section is from the book "Handbook Of Hardy Trees, Shrubs, And Herbaceous Plants", by W. Botting Hemsley. Also available from Amazon: Handbook of hardy trees, shrubs, and herbaceous plants.
Erect perennial poisonous herbs with palmately divided leaves. Flowers in racemes or panicles, blue, purple, yellowish, or white Sepals 5, the dorsal or upper one helmet-shaped, the two lateral broader than the two anterior. Petals 5, small, the two upper with long claws hooded at the tip; the three inferior smaller or undeveloped. Carpels 3 to 5, sessile, free, many-seeded. The classical name. There are about twenty species, natives of the mountains of the north temperate zone.
1. A. Napellus (fig. 16). - Common Monkshood. This is found in almost every old cottage garden. The typical form has blue flowers, but there are several varieties with white and blue flowers, differing in size and form. A widely distributed plant throughout temperate Europe and Asia.
2. A. Lycoctonum. Wolfsbane. - Very distinct from the foregoing, attaining a height of 6 or 7 feet, having large deeply divided leaves and yellowish flowers. Like the last, a Summer-flowering plant. Native of the South of Europe.
Zanthorhiza apiifolia, Yellow-root, is a dwarf shrubby plant from North America, with pinnate or bipinnate leaves and panicled racemes of drooping dull purple regular flowers. Sepals 5. Petals 5, smaller than the sepals, clawed. Hydrastis Canadensis, Orange-root, is an allied herbaceous perennial with one large lobed radical leaf and two smaller ones on the flower-scape, which bears one small greenish flower destitute of petals. Actoea spicata, Baneberry, is a native plant of this affinity. It is a perennial, with ternately divided leaves and small racemose flower succeeded by a several-seeded bluish-black berry. North of England, and northern temperate regions generally.
Fig. 16. Aconitum Napellus. (1/5 nat. size.)