Carlowrightia parvifolia Brandegee

  • Authority

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

  • Family

    Acanthaceae

  • Scientific Name

    Carlowrightia parvifolia Brandegee

  • Type

    Type. Mexico. Coahuila: Sierra de la Paila. Oct 1910, Purpus 4751 (UC!, holotype; F!, GH!, MO!, US!, isotypes).

  • Description

    Species Description - Spreading to erect, spindly subshrub to 5 dm high, arising from a woody caudex to 10 mm in diameter. Older stems quadrate to terete or irregularly fissured, 0.5-1.5 mm in diameter, pubescent or glabrate. Younger stems green or gray-canescent, quadrate to terete, smooth to multistriate with numerous inconspicuous ridges and grooves, 0.5-1.5 mm in diameter, evenly pubescent, the trichomes eglandular, retrorse, (0.1-)0.2-0.6(-1.0) mm long (strigose). Leaves ascendent, sessile; laminas linear to narrowly lanceolate, 3-24 mm long, 0.5-3.0 mm wide (often reduced in size acropetally), mostly (2.5-)4.0-9.0 times longer than wide, acute at base, acuminate to acute at apex; margins flat, frequently strigose-ciliate, especially near base; upper surface glabrous, lower surface scattered strigose, especially along the midvein; midvein only evident. Reduced dichasia solitary or opposite at the nodes, pedunculate from leaf axils, especially along the upper portion of the stem (the stem infrequently branched into a leafy thyrse at its apex), the peduncles (0.5-)2.0-10.0 mm long; flowers usually 1-3 per dichasium, each sessile or pedicellate, subtended by 2 bractlets, the pedicels 0.5-3.0 mm long, the lateral flowers (if present) often borne on secondary peduncles to 4 mm long. Bractlets linear, 2-8 mm long, 0.3-0.8 mm wide, pubescent like leaves. Secondary bractlets linear, 1 -2 mm long, 0.2-0.4 mm wide. Calyx 3.0-5.0 mm long, the outer surface strigose, the inner surface sericeous with appressed trichomes to 0.5 mm long; tube 1.21.8 mm long; lobes subulate, 1.9-2.8 mm long. 0.3-0.5 mm wide at base. Corolla subactinomorphic. light purple with dark purple lines in a smooth, whitish eye (lacking papillae) on the upper lip, 6.5-9.0 mm long, strigose on outer surface; tube 1.8-2.5 mm long, 0.9-1.0 mm in diameter; upper lip oblanceolate to spatulate, 4.5-7.0 mm long, 1.5-2.5 mm wide, emarginate at apex; lower lip 4.5-7.0 mm long, the lobes identical in form, reflexed, oblanceolate to elliptic, 4.5-7.0 mm long, 1.2-2.5 mm wide. Stamens 4.0-6.0 mm long; filaments purplish, 5.0-5.5 mm long, 0.1-0.2 mm wide at base, pubescent with trichomes 0.1-0.2 mm long; anthers yellowish, thecae 0.8-1.0 mm long. Disc 0.3-0.4 mm high. Style 5.0-6.0 mm long, glabrous. Stigma lobes 0.2-0.3 mm long. Capsules 7-9 mm long, glabrous or sparingly pubescent at apex with eglandular trichomes 0.1-0.2 mm long; stipe 2.5-4.0 mm long; head spherical to partially flattened, 4.0-5.0 mm long (including a terminal beak 0.5-1.0 mm long), 3.0-3.5 mm wide; retinacula 1.3-1.5 mm long. Seeds usually 2 (rarely 3 or 4) per capsule, concavoconvex, obliquely cordate in outline, 3.0-3.9 mm long, 2.5-3.5 mm wide, acute to rounded at apex; testa tuberculate on concave (inward-facing in capsule) side, papillose on convex (outward-facing in capsule) side, margins dentate, the teeth often widely scattered or restricted to the base, with retrorse barbs (third or fourth seeds, if present, often with poorly developed ornamentation on the testa and with exaggerated marginal teeth). Flowering. This species begins sporadic flowering in early July and continues to flower into October.

  • Discussion

    Discussion. Carlowrightia parvifolia differs from other species of section Tuberculosperma by the combination of its light purple corollas, sessile leaves, and glabrous capsules. Its closest relative appears to be C. albiflora which occurs in Tamaulipas. The species occurs sympatrically with C. mexicana, C. texana, and C. torreyana but attempts to artificially hybridize these species were not very successful.

    Distribution and Ecology: Carlowrightia parvifolia is known only from the Chihuahuan Desert of Trans-Pecos Texas and Coahuila (Fig. 14). Standley (1926) reported its occurrence in Nuevo Leon, most of which lies outside the Chihuahuan Desert, but specimens annotated as C. parvifolia from that state prove to be other species. This rarely-collected species is often a common subshrub in crevices and rocky washes on limestone slopes in associations with Acacia, Mimosa, Flourensia, Agave, Euphorbia, Larrea, and Parthenium at elevations of 1200 to 1500 meters.

  • Distribution

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