GREENMAN, — GENUS HOUSTONIA. 287 
angustifolia, Michx., var. rigidiuscula, Gray, Syn. Fl. N. A. i. pt. 2, 
27, in part. — Corpus Christi, Texas, Palmer, without number, collected 
in 1879; Heller, no. 1812. 
* * Low-tufted leafy species, 2 to 12 cm. high: pedicels reflexed in fruit: cap- 
sule one fourth inferior; seeds open-crateriform, oblong-rotund, with a median 
longitudinal ridge on the hilar surface. 
+ Distinctly perennial, multicipital from a deep ligneous root. 
H. Wrightii, Gray. Stems quadrangular, pruinose-puberulent : 
leaves linear or the lower narrowly spatulate, thickish, glabrous ; stipules 
rather pronounced, broadly deltoid, entire or minutely denticulate: flow- 
ers dimorphous, 5 to 7 mm. long, in terminal leafy cymes: calyx-divisions 
lance-linear, acute, 1} to 2 mm. long, glabrous: corolla salver-shaped ; 
tube 2} to 4 mm. long (depending upon the long- or short-styled form 
respectively ), slightly enlarged above: seeds scrobiculate. — Proc. Am. 
Acad. xvii. 202, & Syn. Fl. N. A. i. pt. 2,26. HZ. humifusa, Hemsl. 
Biol. Centr.-Am. Bot. ii. 30, not Gray. Hedyotis (Houstonia) humi- 
fusa, Gray, Pl. Wright. i. 82. Oldenlandia ( Houstonia) humifusa, Gray, 
Pl. Wright. ii. 68, exel. syn. — State of Mexico, in meadows on the 
Sierra de las Cruces, elevation 3,000 m., Pringle, no. 5744; on the 
Serrania de Ajusco, altitude 3,000 m., Pringle, no. 6468; San Luis 
Potosi, elevation 1,800 to 2,460 m., Parry & Palmer, no. 301; in the, 
Vicinity of the city of Durango, Palmer, no. 312; Chihuahua, on the 
summits of Sierra Madre, Pringle, no. 2284; and on dry mountain sides, 
Chuchuichupa, in the same State by C. V. Hartman, no. 705; New 
Mexico, Wright, no. 241, Thurber, nos. 717, 1121; Santa Magdalena 
Mountains, Vasey ; near Santa Rita del Cobre, E. L. Greene; Arizona, 
at Fort Whipple, Coues & Palmer, no. 75; in the San Francisco Moun- 
tains near Clifton, E. L. Greene; Prescott, Dr. Smart, no. 460; Lem- 
mon, nos. 2726, 512, 5121; in the Rincon and Santa Rita Mountains, 
Pringle; at Willow Spring, Palmer, no. 523. 
H. rubra, Cav. Much depressed, rather dense, 2 to 10 cm. high: 
stems and leaves hispidulous or nearly glabrous: leaves linear, or the 
lower oblanceolate-linear, 5 to 25 mm. long; stipules short with one or 
more sete: flowers 1} to 21 cm. long, axillary: calyx-divisions linear, 
acute, in anthesis 2 mm. long, in fruit somewhat elongated: corolla red 
or purple varying to white; tube slender: capsule depressed, subro- 
tund; seeds scrobiculate. — Ie. v. 48, t. 474, f. 1; Benth. Pl. Hartw. 15; 
Hemsl. Biol. Centr.-Am. Bot. ii. 30; Gray, Syn. Fl. N. A. i. pt. 2, 25. 
Oldenlandia (Houstonia) rubra, Gray, Pl. Wright. ii. 68. — Aguas 
Calientes, Hartweg, no. 93; Valley of San Luis Potosi, Schaffner, 
