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..
Erect glabrous annual herbs, with elliptic or ovate entire leaves, sessile and cordate or the lower narrowed at the base, and middle-sized yellowish flowers in terminal racemes. Sepals and petals narrow. Style 2-lobed or entire. Siliques elongated-linear, 4-angled, the valves firm, 1-3-nerved. Seeds in 1 row in each cell, oblong, marginless; cotyledons incumbent. [In honor of Hermann Conring, 1606-1681, Professor at Helmstädt]
About 7 species, natives of Europe and Asia. Type species: Brassica orientalis L.
1. Conringia orientàlis (L.) Dumort.
Hare's-ear, Treacle Mustard.
117. 1812. Conringia perfoliata Link, Enum. 2: 172. 1822. C. orientalis Dumort. Fl. Belg. 123. 1827.
Stem usually erect, simple, or somewhat branched, 1°-3° high. Leaves light green, obtuse at the apex, 2'-5' long, 1/3'-2' wide, the upper smaller; racemes at first short, much elongating in fruit; pedicels slender, ascending, 4"-8" long; petals about 1/2' long; nearly twice as long as the sepals; pods 3'-5' long, about 1" wide, 4-angled, spreading.
29. HÉSPERIS [Tourn.] L. Sp. Pl. 663. 1753.
Erect perennial or biennial herbs, pubescent with forked hairs, with simple leaves and large racemose purple or white flowers. Stigma with 2 erect lobes. Siliques elongated, nearly cylindric, the valves keeled, dehiscent, 1-nerved. Seeds in 1 row in each cell, globose, wingless; cotyledons incumbent. [Name from Hesperus, evening, when the flowers are most fragrant.]
About 25 species, natives of Europe and Asia. Type species: Hesperis matronalis L.
Hesperis matronalis L. Sp. Pl. 663. 1753.
Erect, simple or sparingly branched above, 2°-3° high. Lower leaves 3'-8' long, tapering into a petiole, ovate or ovate-lanceolate, acute, dentate with minute teeth, pubescent on both sides; upper leaves similar but smaller, sessile or short-petioled; flowers 8"-12" broad, pink, purple or white, fragrant; blade of the petals widely spreading, about as long as the claw; pods 2-4' long, spreading or ascending, contracted between the seeds when ripe.
In fields and along roadsides, escaped from gardens, Nova Scotia to Ontario, Pennsylvania and Iowa. Native of Europe and Asia. May-Aug. Old English names are Queen's- or Dame's-gilliflower; night-scented, rogue's- or winter-gilliflower. Damask-violet. Sweet-rocket. Summer-lilac.