Carlowrightia hintonii T.F.Daniel

  • Authority

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

  • Family

    Acanthaceae

  • Scientific Name

    Carlowrightia hintonii T.F.Daniel

  • Type

    Type. Mexico. Guerrero: Manchon (ca. Lat. 18° 07' N, Long. 100° 59' W), 30 Dec 1937, Hinton 11326 (GH!, holotype; LL!, MICH!, NY!, UC!, US!, isotypes).

  • Description

    Latin Diagnosis - Suffrutex usque ad 5 dm altus. Caules juniores saepe multistriate pubescentes trichomatibus glan-dulosis et eglandulosis. Folia petiolata; petioli (0.5-)3-35 mm longi; laminae ovatae (lanceolatae), (6-)l 1-75 mm longae, (3-)6-27 mm latae, 1.8-2.8(-4.5)-plo longiores quam latiores. Dichasia redacta floribus 1-3, sessilia in axillis bractaerum. Calyces 3.5-6.0 mm longi, extus glandulosi. Corollae pseudopapilionaceae, 17.0-18.5 mm longae. Capsulae 11-15 mm longae, extus pubescentes. Semina 4.0-4.8 mm longa, 4.0-4.5 mm lata; testae laeves vel papillosae, ad margines irregulariter alata.

    Species Description - Erect to spreading subshrub to 5 dm high. Older stems terete, 1.5-3.0 mm in diameter, pubescent with a mixture of eglandular and glandular trichomes or glabrate. Younger stems terete, multistriate, the grooves greenish, the ridges brownish, 0.5-1.5 mm in diameter, pubescent with a mixture of eglandular and glandular trichomes (see discussion). Leaves horizontal, petiolate; petioles (0.5-) 3.0-35.0 mm long, pubescent like younger stems; laminas ovate (lanceolate), (611-75 mm long, (3-)6-27 mm wide (reduced in size acropetally), mostly 1.8-2.8(-4.5) times longer than wide, (acute) rounded to truncate (often oblique) at base, acute at apex; margins flat, ciliate with cauline type trichomes (or usually eglandular trichomes only on the larger leaves); surfaces pubescent like younger stems (or usually eglandular trichomes only on the larger leaves); several orders of venation evident. Inflorescence typically consisting of lateral or terminal, usually helicoid, spicate axes which are frequently branched into panicles to 15 cm long. Inflorescence axes pubescent with a mixture of eglandular and glandular trichomes (see discussion). Reduced dichasia solitary at nodes, each sessile in the axil of a bract; flowers 1-3 per dichasium, each sessile, subtended by 2 bractlets. Bracts narrowly ovate to narrowly lanceolate to subulate, 1.5-3.0 mm long, 0.5-1.0 mm wide, pubescent like inflorescence axes. Bractlets narrowly lanceolate to subulate, 1.5-2.5 mm long, 0.5-0.8 mm wide, pubescent like inflorescence axes. Calyx 3.5-6.0 mm long, the outer surface pubescent like inflorescence axes, the inner surface sericeous with appressed trichomes 0.2-0.5 mm long; tube 1 mm long; lobes subulate, 2.5-5.0 mm long, 0.5-0.7 mm wide at base. Corolla pseudopapilionaceous, white (label data) with a papillate (yellow?) eye on the upper lip, 17.0-18.5 mm long, pubescent on outer surface (rarely only minutely so), especially on the lower-central lobe, the trichomes 0.2 mm long; tube 7.5-8.5 mm long, 1.5-2.0 mm in diameter; upper lip spatulate, 8.5-9.0 mm long, 3.5 mm wide; lower lip 9.5-10.5 mm long, the lateral lobes obovate-elliptic, 8.5-9.5 mm long, 3.5-4.0 mm wide, the lower lobe conduplicate-keeled, 9-10 mm long, 4-5 mm wide. Stamens 6-8 mm long, filaments 5.5-7.5 mm long, 0.7 mm wide at base, pubescent with trichomes 0.05-0.10 mm long; thecae 1.0-1.5 mm long. Disc 0.5 mm high. Style 13 mm long, glabrous. Stigma lobes 0.2 mm long. Capsules 11-15 mm long, pubescent with glandular and/or eglandular trichomes 0.2-0.4 mm long (see discussion); stipe 5-7 mm long; head flattened, 6-8 mm long (including a terminal beak to 1 mm long), 4.8-5.0 mm wide; retinacula 2.0-3.5 mm long. Seeds usually 4 per capsule, flat or somewhat concavoconvex with a prominent, swollen marginal ring, obliquely circular to elliptic in outline, 4.0-4.8 mm long, 4.0-4.5 mm wide, rounded at apex; testa smooth to papillose; margin fringed with irregular, wing-like projections. Flowering. This species has been collected in flower in late December and January.

  • Discussion

    Discussion. This poorly known species differs from other species in section Pseudopapilionacea by its pubescent capsule and unusual seeds. The two collections of C. hintonii differ from one another in numerous features. In the type collection from western Guerrero, the cauline pubescence consists of an understory of sparse, erect to retrorse, eglandular trichomes 0.1 to 0.2 mm long and dense, glandular trichomes 0.05 to 0.20 mm long and an overstory of dense glandular trichomes 0.2 to 0.8 mm long; the pubescence of the inflorescence axes consists of an understory of eglandular and glandular trichomes 0.05 to 0.10 mm long and an overstory of glandular trichomes 0.4 to 1.0 mm long; the pubescence on the capsule is all or chiefly glandular; the capsule ranges in length from 11 to 14 mm with the head longer than the stipe; and the inflorescence is poorly developed with only one flower per dichasium and the panicle reaching a length of only 6 cm. In Standley and Padilla’s specimen from western El Salvador, the cauline pubescence consists of an understory of glandular trichomes 0.05 to 0.20 mm long and an overstory of flexuose, often dense, eglandular trichomes 0.2 to 0.5 mm long; the pubescence of the inflorescence axes consists of an understory of glandular trichomes 0.05 to 0.20 mm long and an overstory of eglandular and glandular trichomes 0.2 to 0.5 mm long; the pubescence on the capsule is all or chiefly eglandular; the capsule ranges in length from 14 to 15 mm with the stipe longer than or equal to the head; and the inflorescence is more elaborate with 1 to 3 flowers per dichasium and the panicle reaching a length of 15 cm. Although there are no open flowers on the specimen from El Salvador, the buds indicate that there is little pubescence on the outside of the corollas of that individual.

    Although it may be argued that the differences between these specimens taken together with their geographic separation would support the recognition of two varieties, the nature of the differences and the paucity of material suggests otherwise. In keeping with the treatment of variation encountered in other species of Carlowrightia, these specimens are regarded as constituting a single taxon. The nature, amount, and disposition of pubescence is often equally or more variable over the range of related species. The amount of development of the inflorescence may be a seasonal (the Mexican material was collected earlier than the material from El Salvador) or environmental response. The differences in size of the capsules is similar to the differences encountered in other species of the genus. Clearly, more material is desirable in order to determine whether these differences have a taxonomic significance or whether they merely represent artifacts of insufficient collection.

  • Distribution

    Carlowrightia hintonii is known from only two localities: an arroyo in the oak forest zone of Guerrero, Mexico, between 1100 and 1700 meters elevation, and in a dry thicket in Ahuachapán, El Salvador, between 700 and 1100 meters elevation.

    El Salvador Central America| Ahuachapán El Salvador Central America|