Carlowrightia glandulosa B.L.Rob. & Greenm.

  • Authority

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

  • Family

    Acanthaceae

  • Scientific Name

    Carlowrightia glandulosa B.L.Rob. & Greenm.

  • Type

    Type. Mexico. Oaxaca: Monte Alban near Oaxaca, elev. 5500 ft, 5 Dec 1895, Pringle 6276 (GH!, holotype; CAS!, ENCB!, F!, MO!, MSC!, NY!, UC!, US!, isotypes).

  • Synonyms

    Justicia pulchella Sessé & Moc.

  • Description

    Species Description - Erect to spreading, viscid subshrub to shrub to 1 m high, arising from a woody caudex to 15 mm in diameter or a woody rhizome to 4 mm in diameter. Older stems quadrate to terete or irregularly fissured, 2.0-3.5 mm in diameter, pubescent or glabrate. Younger stems green, terete to quadrate, smooth to multistriate, 0.5-1.5 mm in diameter, pubescent with a mixture of eglandular and glandular trichomes, the eglandular trichomes more or less evenly disposed or frequently concentrated in 2 vertical, decussate lines, sparse to dense, retrorse to erect, 0.3-1.0 mm long (strigose), the glandular trichomes evenly disposed, dense to infrequent, 0.2-1.0 mm long (rarely inconspicuous or nearly absent at base of new growth). Leaves horizontal to ascendent, petiolate; petioles 2-20(-40) mm long, pubescent like the younger stems; laminas ovate to deltate to cordate, (3-)5-40 (-77) mm long, (1.5-)3.0-25.0(-55.0) mm wide (sometimes reduced in size acropetally into flower-bearing bracts), mostly 1.4-2.7 times longer than wide, acute to truncate to cordate at base, acute at apex; margins entire (rarely undulate or strongly crisped), flat to slightly revolute, glandular strigose-ciliate; surfaces pubescent like the younger stems or lacking most of the glandular trichomes, the upper leaves often more glandular than the lower leaves; several orders of venation prominent on both surfaces. Reduced dichasia solitary or opposite at the nodes, sessile or short (to 2.5 mm long) pedunculate in leaf axils, the dichasia sometimes borne in the axils of bracts forming helicoid or scorpoid spicate axes to 15 cm long, these collectively forming leafy panicles (inflorescence axes, if present, pubescent like the younger stems or the eglandular trichomes less frequent); flowers 13 (or more) per dichasium, each sessile or short (to 0.5 mm long) pedicellate, subtended by 2 bractlets. Bracts (if present) sessile to subsessile, lance-elliptic, 3.0-7.5 mm long, 1.0-1.5 wide, pubescent like the inflorescence axes. Bractlets frequently petiolate, ovate to lance-elliptic to subulate, (1-)3-12 mm long, 0.5-3.0 mm wide, pubescent like the leaves. Calyx often accrescent, (3.5-)4.0-6.0 (-10.0) mm long, the outer surface glandular strigose, the inner surface (glabrous) sericeous with appressed, eglandular trichomes 0.2-0.4 mm long; tube 0.5-1.5 mm long; lobes subulate, 4.0-6.0(-8.5) mm long, 0.5-1.0 mm wide at base. Corolla pseudopapilionaceous, white within with a papillate, yellow or green-yellow eye fringed with purple veins on the upper lip, the lower-central lobe either yellow or purple on the outer surface, the lateral lobes either entirely white or purple where exposed in bud on the outer surface, (13-)15-19(-26) mm long, strigose on the outer surface; tube 3.5-5.0(-9.0) mm long, 1-2 mm in diameter; upper lip spatulate, 10-15 mm long, 5.0-6.5 mm wide, emarginate at apex; lower lip 12-17 mm long, the lateral lobes obovate-elliptic, 11-16 mm long, 4-7 mm wide, the lower lobe conduplicate-keeled, bent upwards, 10-14 mm long, 3.0-4.5 mm wide. Stamens 6-10 mm long; filaments white, 5-9 mm long, 0.4-0.6 mm wide at base, pubescent with trichomes 0.1-0.2 mm long, especially near the base; thecae maroon turning black, 0.8-1.2 mm long. Disc 0.2-0.5 mm high. Style 9-15 mm long, glabrous. Stigma lobes 0.2 mm long. Capsules 10-16 mm long, glabrous; stipe 57 mm long; head flattened, 5-9 mm long (including a terminal beak 0.7-1.3 mm long), 4-5 mm wide; retinacula 2-4 mm long. Seeds usually 4 per capsule, brown mottled with black, flat, obliquely cordate in outline, 4.0-5.8 mm long, 3.5-5.2 mm wide, rounded to acute at apex; testa papillose (rarely hardly so or smooth); margins entire to irregularly crenulate to dentate, the teeth with retrorse barbs. Flowering. Carlowrightia glandulosa begins to flower in August, reaches peak flowering during the months of October through December and continues to flower into April.

  • Discussion

    Discussion. Justicia pulchella Sessé & Mociño was described in Plantae Novae Hispaniae in 1887. In the protologue, a plate (Fl. Mex. Ic. 190) was cited as well as a locality ("Habitat prope Mitequense flumen" ). Examination of a photograph of the plate (Field Museum neg. 30839), photographs of two specimens (nos. 283 and 305) labelled Justicia pulchella in the Sesse and Mociño herbarium at MA, and fragments of both specimens at F reveal this species to be C. glandulosa. Although the Sesse and Mociño name was published prior to that of C. glandulosa, J. pulchella Sessé & Mociño is a later homonym, and according to Articles 64 and 45 of the International Code of Botanical Nomenclature (Stafleu et al., 1978) is illegitimate and cannot be considered for purposes of priority.

    The lectotype is here designated as Sessé et al. 283 (MA). The type locality has not been located, although it may be in southwestern Mexico. In their description of J. pulchella, Sessé and Mociño note that the lateral petals are purplish without, a frequent phenomenon in specimens of C. glandulosa from southwestern Mexico.

    Carlowrightia glandulosa is a widespread and variable species which appears to have close morphological relatives in both C. serpyllifolia and C. arizonica. The following couplet distinguishes C. serpyllifolia from C. glandulosa:

    Calyx lobes 1.0-5.0 mm long; corolla pink or blue-purple within, 9-15 mm long, the upper lip 2.8-3.8 mm wide; filaments purplish, 0.2-0.3 mm wide at base; stipe 3-5 mm long, retinacula 1.5-2.0 mm long; mature seeds black; restricted to the Chihuahuan Desert.

    C. serpyllifolia.

    Calyx lobes 4.0-8.5 mm long; corolla white within, 13-26 mm long, the upper lip 5.0-6.5 mm wide; filaments white, 0.4-0.6 mm wide at base; stipe 5-7 mm long, retinacula 2-4 mm long; mature seeds brown, mottled with black; occurring outside (east and south of) the Chihuahuan Desert.

    C. glandulosa.

    Vegetatively, C. serpyllifolia is usually a low, often intricately branched plant with smaller, more orbicular (never cordate) leaves than C. glandulosa, which tends to be an erect, openly branched subshrub to shrub with larger, more ovate to cordate leaves. Specimens of C. serpyllifolia often resemble exposed or drought forms of C. glandulosa and since both plants have similar pubescence, one must often resort to characters of the flower and/or fruit for identification. First generation artificial hybrids between C. serpyllifolia and C. glandulosa have a very low pollen stainability and fail to produce seeds. The ranges of these species do not overlap.

    The differences between C. glandulosa and C. arizonica are less evident due to the great range of variability exhibited by both of these species. In general, C. glandulosa is a more viscid plant with dense, conspicuous glandular trichomes, which are rarely infrequent on the older growth. Most forms of C. arizonica lack conspicuously glandular vegetative shoots, however one from Baja California Sur resembles some forms of C. glandulosa by its conspicuous cauline glands. This form may be distinguished from C. glandulosa by its eglandular leaves, flowers in slender spicate axes with narrowly lanceolate to subulate bracts which are 0.7 to 1.2 mm wide, and long (1.2-1.5 mm) thecae. In contrast, most forms of C. glandulosa have glandular leaves, flowers borne in the leaf axils (or if in spicate axes, the spikes stout with lance-elliptic bracts which are 1.0-1.5 mm wide), and short (0.8-1.2 mm) thecae. In all forms of C. arizonica, the length of the calyx varies from 1.5 to 5.5 mm in length and the seed margins are dentate whereas in C. glandulosa, the calyx varies from 3.5-10.0 mm in length and in many individuals, the seed margins are entire or crenulate. Despite their morphological similarity, artificial crosses between these species fail to set fruit.

    The variation encountered in C. glandulosa with respect to four characters is depicted in Figure 22. The character states (proceeding from the center to the periphery of each axis) for each character are: calyx length (1 to 10 mm), bractlet length (1 to 10 mm), corolla length (10 to 22 mm), and seed margin (entire, crenulate, dentate).

    The extreme variation in seed morphology of C. glandulosa is perplexing because features of the testa and margin are usually constant in other species of the genus. In C. glandulosa, the topography of the testa ranges from smooth to densely papillose and the margin ranges from entire to crenulate to distinctly dentate, the teeth bearing retrorse barbs. Variation in the topography of the testa of mature seeds appears to have little taxonomic significance as the full range from smooth to papillose may be encountered on the same specimen. Indeed, plants from all portions of the range of C. glandulosa exhibit this variation. The extent of development of the margin, on the other hand, appears to vary geographically. Plants from the southern and western portion of the range (Oaxaca, Puebla, Guerrero, Jalisco, and Guanajuato) typically have seeds with a well-developed, peripheral band, extending to a narrow (to 0.1 mm wide) flange which is either continuous (an entire margin) or irregularly broken (crenulate), however neither the peripheral band nor the flange is as extensive as those of C. hintonii. Rarely, this marginal flange breaks up into a few teeth with retrorse barbs. This latter phenomenon is especially well-developed in some specimens from Morelos. Seeds of plants from the northeastern portion of the range (Tamaulipas, Nuevo León, San Luis Potosí, and Hidalgo) show little development of a peripheral band, and lack a marginal flange. Instead, the margin consists of numerous, more or less regular teeth with retrorse barbs. Seeds of specimens from Querétaro vary from entire to crenulate to dentate.

    It is not known whether these differences represent two distinct types of seed or merely illustrate a continuum. The extreme types, occurring at the two ends of the range with numerous intermediate types between, suggest the latter. The break-up of the marginal flange of the southwestern specimens may well have given rise to the dentate seeds which characterize the northeastern ones.

    In addition to corolla size, the color of the corolla is variable in C. glandulosa. In most specimens the outer surface of the corolla is white and the lower-central petal lobe is yellowish. In some specimens, particularly from southwestern Mexico, the outer surfaces of the lower-central petal lobe and the upper half of the lateral lobes are purplish (i.e. those parts of the corolla exposed in bud are purplish). On drying, flowers of the former type frequently take on the purplish coloration of the latter type.

    Vegetatively, individuals can be compact, often very reduced plants, with laminas to 12 mm long and 7 mm wide and with internodes of the younger shoots ranging from 2 to 30 mm long (Purpus 463, Palmer 1014, Carlson 2795, Kenoyer 392, Rzedowski 31516, and Rzedowski s.n. 17 Nov 1974). These plants are encountered throughout the range of the species and apparently represent exposed or drought-induced forms. At the outer extreme, a specimen (Daniel 1128) collected in full shade on a moist roadbank is a tall, openly branched plant with leaves to 77 mm long and 55 mm wide and with internodes of the younger shoots ranging from 40 to 90 mm long.

    Distribution and Ecology: This widespread species ranges from Tamaulipas and Nuevo León, southward through San Luis Potosí, Jalisco, Guanajuato, Querétaro, Hidalgo, Puebla, Michoacán, Morelos, and Guerrero to Oaxaca (Fig. 20). It grows in the rocky soils of slopes and washes, pastures, and roadside thickets in thorn-scrub associations to mixed pine forests at elevations of 900 to 2200 meters. Associates include species of Agave, Bursera, Ipomoea, Opuntia, Heliocarpus, Neopringlea, Montanoa, Pinus, and Quercus.

  • Distribution

    Mexico North America| Guerrero Mexico North America| Hidalgo Mexico North America| Jalisco Mexico North America| Michoacán Mexico North America| Morelos Mexico North America| Nuevo León Mexico North America| Oaxaca Mexico North America| Puebla Mexico North America| Querétaro Mexico North America| San Luis Potosí Mexico North America| Tamaulipas Mexico North America|