Hechtia carlsoniae Burt-Utley & Utley
Literature references:
Comments:
- Hechtia carlsoniae is the only species in the genus known to produce predominantly simple pistillate inflorescences, Only one compound pistillate inflorescence was observed at the type locality; however, all staminate inflorescences observed were compound, like those of other species of Hechtia. Whereas staminate inflores¬cences of H. carlsoniae are typically bipinnate, occasional weakly tripinnate inflorescences were encountered. Although capsules were less nu¬merous on simple pistillate inflorescences than on the compound inflorescence collected (15¬-47 vs. 74), the capsules were generally larger [(11)13-16.5 vs. 9.5-12 mm long]. Petals were also larger on flowers on racemose inflores¬cences (5.5-7.5 vs. 4.2-5 mm long), as were the floral bracts. Floral bracts on unbranched inflo¬rescences were similar in size to those observed toward the apex of the compound inflorescence, but larger than those on lateral branches. Al¬though bracts subtending flowers on the main axis of an inflorescence in the Bromeliaceae are typically treated as floral bracts (e.g., Smith and Downs 1974), it seems likely that the larger flo¬ral bracts observed on simple inflorescences of H. carlsoniae are modified primary bracts. Lower scape bracts of H. carlsoniae are unusual in hav¬ing sheaths that are auriculate on either side of the linear-attenuate blade. However, upper¬most scape bracts resemble primary bracts and could be considered primary bracts because they conceal undeveloped lateral branches. Lateral branches not only varied greatly in length on staminate inflorescences, but also ranged from fertile throughout to sterile proximally de¬pending on the lateral branch and inflorescence examined.
Hechtia carlsoniae appears most closely allied with H. conzattiana Lyman B. Smith, a species known only from the vicinity of Cuicatlan in northern Oaxaca. These species share a similar open habit with leaf blades cinereously pubes¬cent throughout, terminal inflorescences, and similar staminate flowers. Staminate flowers in both species are short pedicellate with convex, ascending petals, in contrast to species like H. lyman-smithii Burt-Utley & Utley and H. tillands¬ioides (Andre) Lyman B. Smith with spreading petals (Burt-Utley and Utley 1987). Similar cup¬like staminate flowers also have been observed on H. melanocarpa Lyman B. Smith and may be characteristic of other species as well. It should be noted, however, that petal orientation can be determined unequivocally only from living or fluid-preserved material of flowers at anthe¬sis. The most obvious differences between H. carlsoniae and H. conzattiana are in pistillate in¬florescence form and in the orientation and size of pistillate flowers and capsules. In contrast to the characteristically simple pistillate inflores¬cences of H. carlsoniae, those of H. conzattiana (Utley & Utley 6933, 6936, 6938, 6986) are con¬sistently bipinnate. Unlike flowers of H. con¬zattiana, pistillate and often siaminate flowers of H. carlsoniae are conspicuously nutant to sub¬nutant. Pistillate flowers and capsules of H. carl¬soniae are also typically much larger than those of H. conzattiana.
Hechtia carlsoniae is named in honor of Mar¬gery Carlson (1892-1985), a former Professor of Botany at Northwestern University and Re¬search Associate at the Field Museum of Natural History in Chicago. During the late 1940's and early 1950's, she made several trips to Mexico, collecting for the first time Tillandsia carlsoniae Lyman B. Smith and the unusual Hechtia which now bears her name. During this time. Margery
Carlson also traveled to Honduras, EL Salvador, and Costa Rica where she collected interesting species of Begonia, in addition to many other taxa. (Syst. Bot.)
- Hechtia carlsoniae is the only species in the genus known to produce predominantly simple pistillate inflorescences. Only one compound pistillate inflorescence was observed at the type locality; however, all staminate inflorescences observed were compound, like those of other species of Hechtia. Whereas staminate inflorescences of H. carlsoniae are typically bipinnate, occasional weakly tripinnate inflorescences were encountered. Although capsules were less numerous on simple pistillate inflorescences than on the compound inflorescence collected (15-47 vs. 74), the capsules were generally larger [(11)13-16.5 vs. 9.5-12 mm long]. Petals were also larger on flowers on racemose inflorescences (5.5-7.5 vs. 4.2-5 mm long), as were the floral bracts. Floral bracts on unbranched inflorescences were similar in size to those observed toward the apex of the compound inflorescence, but larger than those on lateral branches. Although bracts subtending flowers on the main axis of an inflorescence in the Bromeliaceae are typically treated as floral bracts (e.g., Smith and Downs 1974), it seems likely that the larger floral bracts observed on simple inflorescences of H. carlsoniae are modified primary bracts. Lower scape bracts of H. carlsoniae are unusual in having sheaths that are auriculate on either side of the linear-attenuate blade. However, uppermost scape bracts resemble primary bracts and could be considered primary bracts because they conceal undeveloped lateral branches. Lateral branches not only varied greatly in length on staminate inflorescences, but also ranged from fertile throughout to sterile proximally depending on the lateral branch and inflorescence examined. —See Syst. Bot.
