Cystopteris bulbifera in the Southwestern United States

Abstract

(Wagner, 1972). Anderson (1974) discussed the distribution of this species in the Great Plains but not in the Southwest. Cystopteris bulbifera (L.) Bernh. is known in Texas only in the Guadalupe Mountains, Culberson Co. (Correll & Johnston, 1970). New Mexican collections have been made in these same Guadalupe Mountains, Otero or Eddy Co. (Blasdell, 1963, p. 67); in the White Mountain wilderness, northern Otero Co. (C. R. Hutchins, pers. comm.); and north of Taos, Taos Co. (Dittmer, et al., 1954, p. 28). In Utah, Flowers (1944) reported the species from Zion National Park, Washington Co.; Elk Mountain, San Juan Co.; and Brighton and Little Cottonwood Canyon, Salt Lake Co. There are no reports of this species from Colorado, Nevada, or farther north. In Arizona, C. bulbifera has previously been known only from the West Fork of Oak Creek Canyon, Coconino Co. (Kearney, et al., 1960, p. 44). I have recently collected specimens of it in Walnut Canyon, Coconino Co., at a site about 40 km northeast of the Oak Creek locality. A recent floristic study of Walnut Canyon by Joyce (1974) does not mention the occurrence of C. bulbifera, but my examination of his collections has revealed one specimen of this species (Joyce WC634, ASC) misidentified as C. firagilis (L.) Bernh. Blasdell (1963, p. 28) stated that C. bulbifera usually grows on neutral soils associated with limestone, whereas Anderson (1974) indicated that in Nebraska it occurs on sandstone. In Arizona, I have collected this species on both substrates. Cystopteris bulbifera is abundant in the lower portion of the West Fork of Oak Creek Canyon (1550 m), occurring in large colonies on the red sandstone talus and cliffs capped by Kaibab limestone. Associated fern species are Adiantum capillus-veneris , A. pedatuim, and Polypodium hesperium. At higher elevations in the canyon (2000 m), where Cystopteris fragilis, Dryopteris filix-mas, and Polystichulmio lonchitis are found, the Bulblet Fern occurs on limestone outcrops and boulders. At Walnut Canyon, C. bulbifera occurs in a few small colonies at 1800 m in the narrow gorge to the southwest of the Walnut Canyon National Monument Headquarters. Here, the plants grow in shaded seepage sites on vertical cliffs of Kaibab limestone. Associated species are Cheilanthes feei, Cystopteris fragilis, and Selaginella underwoodii. Putative hybrids between C. bulbifera and C. fragilis from Walnut Canyon are currently under investigation. Since the only previously reported chromosome counts for C. bulbifera were based on specimens from eastern North America, an attempt was made to obtain