Source: https://bioone.org/journals/madro%C3%B1o/volume-59/issue-4
Timestamp: 2019-04-26 08:47:40+00:00

Document:
Carex lemmonii W. Boott is a widespread California endemic. Herbarium and field studies showed its extensive morphological variation included plants called Carex albida L. H. Bailey, previously considered endemic to Sonoma County, California. Due to extensive overlap, characters of the perigynium, achene, inflorescence, and foliage did not separate the two taxa. Carex albida becomes a synonym of the earlier name, Carex lemmonii, which has implications beyond nomenclature. Carex lemmonii is common and is not a conservation priority in California. When merged with Carex lemmonii, the only known natural population of Carex albida will no longer qualify for protection under federal and state endangered species legislation. A key and illustrations are provided for California species in Carex section Aulocystis Dumort.
Although most North American violet species (Viola, Violaceae) produce both showy chasmogamous (CH) flowers and inconspicuous cleistogamous (CL) flowers, some species lack the ability to manufacture the automatically self-pollinated CL flowers. Given that such flowers are considered beneficial as a back-up method of seed production when pollinators are scarce, the ecological and genetic implications of this absence remain unknown. In the current study, we focused on the California endemic violet, Viola pedunculata Torr. & A. Gray, which produces only CH flowers within its habitat in prairies and oak savannahs. Using microsatellites, we quantified the population genetic structure of three mainland populations and one island population in Southern California. We then used allozymes to estimate the outcrossing rate within a single population. Consistent with its production of CH flowers, levels of genetic variation were moderate to substantial within the species (Ap = 6.66, Ho = 0.39), with low but significant structure detected (Θ = 0.11). Furthermore, the high outcrossing rate (0.86) suggests that insect pollinators are frequent enough to ensure adequate seed set. These values were similar to those of a morphologically similar stemmed violet, Viola pubescens Aiton, which produces both CH and CL flowers. Overall, these results are consistent with substantial outcrossing occurring in V. pedunculata through CH flowers, leading to gene flow among populations and potentially counteracting effects of genetic drift.
We measured biomass and frequency of herbaceous species before and 12 years after removal of feral sheep from a grassland on Santa Cruz Island, California. Native grasses, especially Stipa spp., increased dramatically following sheep removal whereas all exotic grasses except Avena spp. decreased, probably reflecting the competitive ability of native grasses as well as differential vulnerability to grazing. Native forbs showed a mixed response, with some species increasing but many decreasing, perhaps because some native forbs benefit from grazing. Almost all exotic forbs decreased, likely because these species benefit from herbivores and their activities. Our results provide encouraging evidence that an island grassland dominated by exotic species has the potential for recovery from severe overgrazing.
Vaccinium parvifolium Sm. (Ericaceae) is an important understory shrub in conifer forests in western North America. Populations putatively classified as V. parvifolium in northern California display alternate berry morphology, consistent with a possible phenotypic diversification or cryptic speciation. Identification of cryptic species or subspecies would influence management guidelines given the limited range of some morphological variants. In order to inform management guidelines, two Vaccinium species were characterized via molecular genetic analyses. Plants of typical V. parvifolium morphology from the coastal areas of northwest California, western Oregon and Washington, atypical plants from Shasta County and the central Sierra Nevada, and one population of V. deliciosum Piper, a congener, were assessed at five nuclear microsatellite loci. Analyses of differentiation, admixture, and phylogenetic relationships indicated that populations displaying atypical morphology were more similar to V. deliciosum than to the typical V. parvifolium. Although additional data are required to determine whether these differences warrant taxonomic treatment within Vaccinium, management plans should consider three distinct gene pools among these populations.
Nomenclature of subdivisions within Phacelia Juss. (Boraginaceae: Hydrophylloideae) reflects an update to the classification of the genus, based largely upon the structure offered in summary by Ferguson. We consider this proposed classification a continuation of efforts to better understand interrelationships within the genus and tribe Romanzoffieae Dumort., and anticipate future research offering insights into systematics of Phacelia. New names, changes in status, and combinations include the following: Phacelia sect. Baretiana Walden & R. Patt., sect. nov.; P. subsect. Bipinnatifidae (Small) Walden & R. Patt., stat. nov.; P. subsect. Cosmantha (Nolte ex A. de Candolle) Walden & R. Patt., stat. nov.; P. subsect. Cosmanthoides (A. Gray) Walden & R. Patt., stat. nov.; P. subsect. Dubiae (Small) Walden & R. Patt., stat. nov.; P. subsect. Eutoca (R. Br.) Walden & R. Patt., stat. nov.; P. sect. Glandulosae (Rydb.) Walden & R. Patt., stat. nov.; P. subsect. Humiles Walden & R. Patt., subsect. nov.; P. subsect. Lineares (Rydb.) Walden & R. Patt., stat. nov.; P. sect. Pachyphyllae Walden & R. Patt., sect. nov.; P. subg. Pulchellae (Rydb.) Walden & R. Patt., stat. nov.; P. sect. Ramosissimae (Rydb.) Walden & R. Patt., stat. nov.; P. subsect. Ranunculacea Walden & R. Patt., subsect. nov.; and P. subsect. Sericeae (Rydb.) Walden & R. Patt., stat. nov.
Dudleya crassifolia is described as new. It belongs to a complex of taxa within subgenus Hasseanthus that have a white (occasionally pale yellow) corolla with a conspicuous, “musky-sweet” odor. It differs from related species of this complex in having a thicker petiole, a leaf blade that is only slightly wider than the petiole, and conspicuous dried leaf bases persisting on the caudex. This species is very rare, currently known only from a single population of scattered individuals (total area of coverage less than one hectare), on sandstone bluffs at Colonet Mesa of north coastal Baja California, Mexico.

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