Carlowrightia parviflora (Buckley) Wassh.

  • Authority

    Daniel, Thomas F. 1983. Carloivrightia (Acanthaceae). Fl. Neotrop. Monogr. 34: 1-116. (Published by NYBG Press)

  • Family

    Acanthaceae

  • Scientific Name

    Carlowrightia parviflora (Buckley) Wassh.

  • Type

    Type. United States. Texas: without specific locality, Buckley s.n. (PH!, holotype).

  • Synonyms

    Drejera parviflora Buckley, Dianthera parviflora (Buckley) A.Gray, Ecbolium parviflorum (Buckley) Kuntze, Carlowrightia linearifolia (Torr.) A.Gray, Carlowrightia angustifolia Brandegee, Carlowrightia lindauiana Standl.

  • Description

    Species Description - Spindly to erect, openly branched subshrub or shrub to 12 dm high, arising from a stout, woody caudex to 20 mm in diameter or a woody rhizome to 5 mm in diameter. Older stems bisulcate or quadrate, becoming terete with age, 2-6 mm in diameter, glabrate. Younger stems green, bisulcate, smooth to multistriate, 0.8-1.8 mm in diameter, pubescent in 2 vertical, decussate lines in the grooves between the ridges, the trichomes eglandular, retrorse, 0.05-0.2(-0.4) mm long (strigose), the internodes rarely glabrous, the nodes usually pubescent with erect to flexuose trichomes, 0.2-1.0 mm long. Leaves ascendent, subsessile to petiolate; petioles often bright red, 0.5-12.0 mm long, pubescent with scattered, erect to flexuose trichomes, 0.2-1.5 mm long; laminas often tinged with red, especially along the midvein, lanceolate to ovate, or linear (more common in the southern portion of the range), 10-70 mm long, 0.8-23.0 mm wide (reduced in size acrop-etally into flower bearing bracts), mostly (2.5-)3.5-15.0(-40.0) times longer than wide, acute to rounded to truncate or oblique at base, acuminate to rounded at apex; margins usually revolute, ciliate with retrorse to flexuose trichomes 0.051.30 mm long, the longer ones near the base of the lamina; upper surface sparsely to densely strigose, the lower surface glabrous or strigose; several orders of venation prominent on wider leaves and often evident on linear leaves. Inflorescence typically consisting of 1 or more slender, spicate axes, 1.5-15(-23) cm long, collectively forming a terminal, leafy panicle. Inflorescence axes pubescent with a mixture of eglandular and glandular trichomes, the eglandular trichomes dense, evenly disposed, 0.1-0.3 mm long, the glands scattered, 0.2-0.4 mm long. Reduced dichasia opposite at the nodes along the inflorescence axis, each sessile in the axil of a bract; flowers 1(-3) per dichasium, each sessile to short (to 1 mm long) pedicellate, subtended by 2 bractlets. Bracts sessile, triangular to ovate, 1.0-4.5 mm long, 0.5-1.2 mm wide, pubescent like inflorescence axis. Bractlets triangular to subulate to lanceolate, 0.6-2.5 mm long, 0.4-1.1 mm wide, pubescent like inflorescence axis. Calyx 2.2-4.7 mm long, the outer surface pubescent like inflorescence axis, the inner surface glabrous to sparsely pubescent; tube 0.5-1.0 mm long; lobes subulate, 1.7-4.0 mm long, 0.4-0.8 mm wide at base. Corolla subactinomorphic, lavender-blue with a white eye (lacking papillae) outlined and streaked with purple veins on the upper lip, (6.5-)8.0-11.0(-13.0) mm long, pubescent on outer surface with trichomes 0.1-0.3 mm long; tube 2.0-4.0 mm long, 0.9-1.5 mm in diameter; upper lip reflexed, oblanceolate to spatulate, 4.0-8.0(-9.4) mm long, 1.2-2.5 mm wide, emarginate at apex; lower lip 4.5-8.3(-9.0) mm long, the lobes identical in form, reflexed, oblanceolate to elliptic, 4.0-8.0 mm long, 1.02.3 mm wide. Stamens 3.8-6.0 mm long; filaments blue, 3.0-5.5 mm long, 0.20.3 mm wide at base, glabrous to sparsely pubescent with trichomes 0.05-0.10 mm long; anthers golden yellow, thecae 1.0-1.6 mm long. Disc 0.3-0.5 mm high. Style 5-10 mm long, glabrous. Stigma lobes 0.2-0.4 mm long. Capsules 8.0-10.2 mm long, glabrous; stipe 3.0-4.2 mm long; head spherical to partially flattened, 5.0-6.5 mm long (including a terminal beak 0.3-1.0 mm long), 3.0-5.0 mm wide; retinacula 1.5-2.5 mm long. Seeds usually 4 per capsule, flat to subconcavoconvex, obliquely cordate in outline, 3.0-4.0 mm long, 3.0-3.5 mm wide, apex rounded; testa papillose to subtuberculate; margins dentate, the teeth with minute retrorse barbs. Flowering. Although this species has been collected with flowers in every month of the year, in the northern part of its range there appear to be two flowering peaks, November through December and March through April. Most of the flowering collections from the southern and western portions of its range are from July through October.

  • Discussion

    Discussion. Carlowrightia parviflora differs from other species of section Carlowrightia by the combination of laminas with revolute margins, glabrous capsules, and glandular inflorescences. It has been found growing near C. torreyana; however, no hybrids were found and none were attempted in the greenhouse.

    Leaf size and shape are the most conspicuous variables with respect to C. parviflora. In the northern portion of its range (Texas, Tamaulipas, Nuevo León, Coahuila, and San Luis Potosí) the laminas are commonly lanceolate to ovate, (2-)4-15(-23) mm wide, and (1.5-)2.5-8(-12.5) times longer than wide. The southernmost specimens from Hidalgo and Queretaro generally have more narrow, linear laminas which are 0.8-2(-2.5) mm wide and (5-)7-30(-44) times longer than wide. Specimens of the latter kind reach their best development in the Rio Panuco Relict Desert region (cf. Hidalgan Desert of Axelrod, 1979) which was contiguous with the Chihuahuan Desert during the post-glacial Xerothermic Period, approximately 12,000 to 5000 years before the present (Morafka, 1977). Such specimens from Ixmiquilpan, Hidalgo (Purpus 1412) were designated as C. angustifolia by Brandegee and similar collections from Querétaro have been annotated as C. lindauiana Standley (a new name for C. linearifolia Lindau). Other specimens from Hidalgo, however, have broad laminas (to 20 mm wide) and are 2.5-4.5 times longer than wide. There appears to be some correlation of leaf type with elevation, the broader leaves usually occurring below 1700 meters and the linear leaves usually occurring above 1700 meters. The northern collections of C. parviflora are all from elevations below 1700 meters and the collections from Queretaro and Hidalgo range in elevation from 1400 to 2800 meters. The preponderance of narrow leaves in the southern portion of the range of this species might therefore be attributable, in part, to its occurrence at the higher elevations there. The occurrence of occasional intermediate leaf types throughout the range of the species and some individuals exhibiting both types preclude the recognition of any intraspecific taxa.

    A specimen which appears to be conspecific with C. parviflora yet which differs by its more or less evenly pubescent stems and inflorescences lacking conspicuous glands was collected at Melchor Muzquiz in north-central Coahuila (Latorre 77) at the northwest edge of the range of the species. Another unusual specimen from north-central Coahuila (Johnston 8958) has linear leaves and lacks conspicuous glands on the inflorescence. The plant is somewhat suggestive of the high elevation forms from Hidalgo and Queretaro. It was collected between 1766 and 2166 meters and was just coming into flower when taken. Until further material is available, these specimens are treated as abnormal individuals of C. parviflora.

    Distribution and Ecology: Carlowrightia parviflora ranges from the Rio Grande plains and gulf prairies of southern Texas, southward through Tamaulipas to Queretaro and Hidalgo, and westward through Nuevo Leon to central Coahuila (Fig. 17). It occurs at elevations of 10 to 2800 meters. The species is usually found on rocky slopes or along arroyos, rocky washes, and roadsides where it grows in the gravel or sandy to loamy soils of chapparal thickets, dry thorn forest, and desert scrub in association with species of Acacia, Larrea, Fouquieria, Karwinskia, Prosopis, Opuntia, Hechtia, and Agave.

  • Distribution

    Texas United States of America North America| United States of America North America| Nuevo León Mexico North America| Coahuila Mexico North America|