This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", 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..
Houstonia serpyllifolia Michx. Fl. Bor. Am.
1: 85. 1803. Hedyotis serpyllifolia T. & G. Fl. N. A. 2: 39. 1841.
Perennial; stems prostrate or diffuse, slender, glabrous, 4-10' long. Leaves orbicular or broadly oval, abruptly petioled, 3"-4" long, sometimes hispidulous; or those of the flowering stems narrower, distant; flowers on terminal and axillary filiform peduncles; corolla usually deep blue, 4"-6" broad, its tube rather shorter than the lobes; capsule similar to that of the preceding species but usually slightly larger, nearly as long as the calyx.
Somerset County, Pennsylvania, to the high mountains of Virginia and West Virginia, South Carolina, Georgia and east Tennessee. May.
Houstonia Linnaei var. minor Michx. Fl. Bor. Am. 1: 35. 1803.
H. patens Ell. Bot. S. C. & Ga. 1: 191. 1821.
Annual, glabrous or nearly so, branched from the base, 1'-6' high. Lower and basal leaves oval or ovate, 5"-6" long, narrowed into petioles often of their own length, the upper narrower and sessile; peduncles axillary and terminal, erect-divergent, 3"-18" long, 1-flowered; corolla violet-blue or purple, 3"-4" broad, its tube about equalling the lobes or somewhat longer; capsule compressed, didymous, 21/2"-3" broad, its upper part free from the calyx and about equalling or exceeding the subulate lobes.
In dry soil, Virginia to Florida, Illinois, Arkansas and Texas. March-April. Star-violet (Texas).
Annual, spreading or diffuse, 1'-2 1/2' high, roughish. Lower and basal leaves oval or ovate, with petioles shorter than or equalling the blade, the upper oblong, sessile; peduncles axillary and terminal, rather stout, 3"-12" long; flowers 4"-5" broad; corolla violet or purple, the tube about as long as the lobes; capsule didymous, compressed, about 3" broad, its upper part free from the calyx and considerably exceeded by the lanceolate foliaceous lobes.
In dry soil, Illinois to Kansas, Arkansas, Tennessee and Texas. March-April.
Hedyotis lanceolata Poir. in Lam. Encycl. Suppl. 3: 14. 1813. Houstonia purpurea calycosa A. Gray, Syn. Fl. 12: 26. 1878. Houstonia lanceolata Britton, Man. 861. 1901. Houstonia calycosa Mohr, Contr. Nat. Herb. 6: 739. 1901.
Perennial, glabrous or pubescent, rather stout, 6'-16' high. Leaves lanceolate to linear-lanceolate, firm in texture, not cil-iate, sessile, or the lowest spatulate and narrowed into petioles; corolla-tube little exceeding the calyx; calyx-lobes lanceolate or lanceolate-subulate, 5" long or less, much exceeding the capsule; capsule ovoid-globose, about 2" thick.
In dry soil, Illinois to North Carolina, Alabama, Tennessee and Oklahoma. Recorded from Maine. Max-June.