Fuertesimalva Fryxell
Contenido
Descripción
Annual or perennial herbs, ascending or erect, with stellate pubescence. Leaves petiolate, the blades ovate or orbicular, usually palmately lobed or parted, crenate or dentate, the upper surface sometimes with appressed simple hairs. Flowers sometimes solitary, usually in axillary scorpioid cymes; involucel of 2 or 3 filiform bractlets; calyx stellate-pubescent, (4-) 5-lobed; corolla purplish (sometimes white), shorter than to slightly longer than the calyx; androecium included, the column glabrous or pubescent, filamentiferous at apex, the anthers sometimes purple, few (sometimes only 5); styles 5-16, the stigmas capitate. Fruits schizocarpic, oblate, glabrous; mericarps 5-16, indehiscent, horseshoe-shaped, with irregular transverse ridges (these sometimes interlocking in the fruit between adjacent mericarps), sometimes with a small endoglossum; seeds solitary, glabrous.A
Discusión taxonómica
Fuertesimaha is an Andean genus (Argentina and Chile to Colombia and Venezuela), with two species (F. jacens and F. limensis) found disjunctly in Mexico, usually from relatively high elevations (generally 1000-3800 m), but from much lower elevations (100-600 m) for F. sanambrosiana and F. peruviana. Keys to the species are found in Krapovickas (1954, 1970), and a revised key is presented in Fryxell, 1996. Chromosome numbers have been reported for several species with counts of 2n = 10, 20, and 30.
Fuertesimalva pertains to the Sphaeralcea alliance, i.e. those genera characterized by a base chromosome number of x = 5. Within this group it is one of the few genera characterized by axillary scorpioid inflorescences, which include Tarasa and, to a more limited extent, the genera Monteiroa and Sphaeralcea, the inflorescences of which conform to this pattern only imperfectly. The genera Fuertesimalva and Tarasa are very similar in leaf morphology and general aspect (as is evident from the plates published by Krapovickas 1954, pl. 1-8), but are strikingly different in fruit morphology. The mericarps of Fuertesimalva are horseshoe-shaped, glabrous, and with characteristic transverse ridges or excrescences dorsally, in a pattern unlike that found in any other malvaceous genus. The mericarps oi Tarasa, by contrast, are apically aristate, notably pubescent, and laterally reticulate, showing a superficial similarity to mericarps oi Sphaeralcea. In addition, the two genera differ in pubescence characters, especially clearly presented in the case of calyx pubescence. Fuertesimalva pubescence is stellate tate, with darkly pigmented stipes.A
Fuertesimalva pertains to the Sphaeralcea alliance, i.e. those genera characterized by a base chromosome number of x = 5. Within this group it is one of the few genera characterized by axillary scorpioid inflorescences, which include Tarasa and, to a more limited extent, the genera Monteiroa and Sphaeralcea, the inflorescences of which conform to this pattern only imperfectly. The genera Fuertesimalva and Tarasa are very similar in leaf morphology and general aspect (as is evident from the plates published by Krapovickas 1954, pl. 1-8), but are strikingly different in fruit morphology. The mericarps of Fuertesimalva are horseshoe-shaped, glabrous, and with characteristic transverse ridges or excrescences dorsally, in a pattern unlike that found in any other malvaceous genus. The mericarps oi Tarasa, by contrast, are apically aristate, notably pubescent, and laterally reticulate, showing a superficial similarity to mericarps oi Sphaeralcea. In addition, the two genera differ in pubescence characters, especially clearly presented in the case of calyx pubescence. Fuertesimalva pubescence is stellate tate, with darkly pigmented stipes.A