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..
Rigid and slender mainly perennial herbs, with small glomerate panicled or solitary flowers, bracted at the base. Calyx top-shaped or campanulate, 5-toothed, 5-15-nerved. Petals 5, long-clawed, the limb emarginate or bifid. Stamens 10. Styles 2. Capsule ovoid or oblong, dehiscent by 4 apical teeth or valves. Seeds compressed, laterally attached; embryo straight, eccentric.
A genus of about 20 species, natives of southern Europe and western Asia, the following typical.
Dianthus Saxifraga L. Sp. Pl. 413. 1753.
Tunica Saxifraga Scop. Fl. Cam. Ed. 2, 300. 1772.
Petrorhagia Saxifraga Ser.; Link, Handb. 2: 235. 1831.
Perennial, tufted, sparsely pubescent or glabrous; stems diffuse or ascending, 4'-8' long, terete, branching. Leaves linear-subulate, erect, very acute, 3"-5" long, less than 1/2" wide, connate at the base, the lower imbricated, the upper distant, their margins scabrous or ciliate; flowers panicled, about 3" broad, pink or purple; calyx campanulate, 5-ribbed, 3" long, twice the length of the scarious-margined acute bracts.