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..
Low branching stellate-pubescent annual or perennial herbs, with small racemose yellow or yellowish flowers. Petals entire. Filaments often dilated and toothed or appendaged. Silicle ovate, oblong or orbicular, compressed, its valves nerveless, the septum thin. Stigma nearly entire. Seeds 1 or 2 in each cell of the pod, wingless; cotyledons accumbent. [Greek, curing madness.]
* Originally spelled Konig. Latinized by R. Brown in 1826.
A genus of 100 species or more, natives of the Old World, some of them known as Madwort.Type species: Alyssum montanum L.

Fig. 2012
Clypeola alyssoides L. Sp. Pl. 652. 1753. Alyssum alyssoides L. Syst. Ed. 10, 1130. 1759.
Alyssum calycinum L. Sp. Pl. Ed. 2, 908. 1763.
Annual, densely erect, simple, or branching from the base, tufted, 3'-10' high. Leaves linear-oblong or spatulate, narrowed at the base, obtuse, entire, 3"-15" long, the lower somewhat petioled; flowers yellowish-white, 1" broad; pedicels spreading or ascending, 2" long in fruit; pods orbicular, 1 1/2" in diameter, margined, minutely pubescent, notched at the apex, tipped with the minute style; sepals persistent around the base of the pod; seeds 2 in each cell; style minute; filaments of the shorter stamens minutely toothed at the base.
In fields, Ontario to Massachusetts, southeastern New York, New Jersey and Iowa, and in ballast about the seaports. Also in the Far West. Naturalized or adventive from Europe. Heal-bite. Heal-dog. Summer.
 
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