WOOTON AND STANDLEY—FLORA OF NEW MEXICO. 607 
4. HOUSTONIA L. Buvets. 
Annual or perennial herbs, sometimes woody at the base or throughout, 30 cm. high 
or less; leaves opposite, entire, often ciliate, mostly narrow; flowers perfect, often 
dimorphous, solitary or cymose; hypanthium subglobose or obovoid; sepals 4; corolla 
white or blue or bright rose pink, narrowly funnelform or salverform; stamens 4; 
ovary 2-celled, the styles united to the narrow stigmas; capsules partly inferior, more 
or less distinctly 2-lobed; seeds few or several in each cell. 
KEY TO THE SPECIES. 
Annual... 2... 02-2222 e eee ee eee eee ee eee eee eee eee eee eee 1. H. humifusa. 
Perennials. 
Leaves fasciculate; stems woody throughout.........-.-.-.-- 2. H. fasciculata. 
Leaves opposite; plants woody only near the base, if at all. 
e Corolla tube 2 cm. long; plants 6 cm. high or less... ... 5. H. rubra. 
Corolla tube less than 1 cm. long; plants more than 6 cm. 
high. 
Pedicels reflexed after anthesis.............------ 6. H. wrightii. 
Pedicels erect. 
Stems glabrous, herbaceous; leaves soft, not 
acerose-tipped..........------------- 4. H, rigidiuscula, 
Stems puberulent, woody below, leaves rigid, 
acerose-tipped.....--.......-2------- 3. H. polypremoides. 
1. Houstonia humifusa A. Gray, Proc. Amer. Acad. 4: 314. 1859. 
Hedyotis humifusa A. Gray, Bost. Journ. Nat. Hist. 6: 216. 1850. 
Type LOCALITY: ‘‘Open gravelly banks of streamlets, near Fredericksburg,’ Texas. 
Rance: Western Texas to eastern New Mexico. 
New Mexico: Twenty miles south of Roswell (Earle 278). 
2. Houstonia fasciculata A. Gray, Proc. Amer. Acad. 17: 203. 1882. 
Type LocaLity: ‘‘Southwestern borders of Texas, at Presidio.”’ 
Rance: Western Texas and southern New Mexico; also in Mexico. 
New Mexico: Organ Mountains ( Vasey). Upper Sonoran Zone. 
3. Houstonia polypremoides A. Gray, Proc. Amer. Acad, 21: 379. 1886. 
Type Locauiry: Santa Eulalia Mountains, near Chihuahua, Mexico. 
Rance: Southern New Mexico and western Texas to Mexico. 
New Mexico: Clayton; BishopsCap; White Mountains; Queen; Gray; Buchanan; 
Lakewood; Torrance. Lower and Upper Sonoran zones. 
4. Houstonia rigidiuscula (A. Gray) Woot. & Standl. Contr. U. 8. Nat. Herb. 16: 
175, 1913. 
Houstonia angustifolia rigidiuscula A. Gray, Syn. Fl. 21: 27. 1878. 
TYPE LOCALITY: Texas. 
Rance: Western Texas and southern New Mexico to Mexico. 
New Mexico: Tucumeari; Lincoln; Queen; James Canyon. Upper Sonoran 
Zone. 
5. Houstonia rubra Cav. Icon. Pl. 5: 48. pl. 474, 1799. 
Hedyotis rubra A. Gray, Mem. Amer. Acad. n, ser, 4: 61. 1849. 
Oldenlandia rubra A. Gray, Pl. Wright. 2: 68. 1853. 
Typr Locaity: ‘Habitat prope oppidum mexicanum Ixmiquilpan.”’ 
Rance: New Mexico and Arizona to Mexico. 
New Mexico: Puertecito; Zuni; Albuquerque; Santa Fe; Fort Wingate; Socorro 
Mountain; Apache Teju; Round Mountain; East View; Buchanan. Dry hills and 
plains, in the Upper Sonoran Zone. 
