This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
[Oxybaphus L'Her.; Willd. Sp. Pl. I: 185. 1797.]
Forking herbs, with opposite equal leaves, and involucres in loose terminal panicles or solitary in the axils of the leaves. Involucre 5-lobed (of 5 partially united bracts), 3-5-flow-ered, becoming enlarged and reticulate-veined after flowering. Perianth campanulate, its tube constricted above the ovary, its limb corolla-like, deciduous. Stamens 3-5, generally 3, unequal, hypogynous. Fruit obovoid or clavate, strongly ribbed, pubescent in most species. [Name in honor of Chas. Allioni, 1725-1804, a botanist of Turin.]
About 40 species, natives of North and South America, one Asiatic. Type species: Allionia ziolacea L.
Leaves narrowly linear, sessile or very nearly so, 4" wide or less.
Leaves from linear-lanceolate to ovate-cordate.
Leaves sessile or nearly so, lanceolate to oblong.
Pubescence fine and short, often wanting below the inflorescence.
Pubescence, or some of it, of long hairs, especially below, and at the nodes.
Leaves manifestly petioled, ovate, often cordate.
Stem slender, terete or somewhat 4-angled below, glabrous, glaucous, 3'-4 1/4o tall, erect, the branches and peduncles sometimes puberulent. Leaves linear, thick, i-nerved, 1/2'2 1/2' long, 1"-4" wide, obtuse or acute at the apex, sessile or the lower occasionally short-peti-oled; involucre about 3-flowered, green before flowering; perianth purple, longer than the involucre; stamens and style exserted; fruit commonly roughened in the furrows between the 5 prominent ribs, pubescent.
In dry soil, Illinois to Minnesota, Wyoming, south to Texas and Mexico. Adventive in Connecticut. June-Aug.
Allionia Búshii Britton and Allionia Bodini (Holz.) Morong, admitted as species in our first edition, prove to be conditions of this species with the involucres solitary in the axils.