Registered users receive a variety of benefits including the ability to customize email alerts, create favorite journals list, and save searches.
Please note that a BioOne web account does not automatically grant access to full-text content. An institutional or society member subscription is required to view non-Open Access content.
Contact firstname.lastname@example.org with any questions.
California beach plants are capable of dealing with harsh conditions, but little is known about how this community responds to human-induced impacts. The objective of this paper is to determine if beaches experiencing higher degrees of impacts from trampling have more cover of two common plant species thought to grow particularly well under difficult conditions, Ambrosia chamissonis (Less.) Greene and Cakile maritima Scop. Seventeen sites were sampled between 2007 and 2009 with one meter wide belt transects and the sites were divided into three groups; high (people walk anywhere on the beach), medium (foot traffic is restricted to trails), and low impact levels (little to no access). Cover of all species present were recorded. Cover of A. chamissonis is statistically higher on beaches with a high level of impact than low and medium levels. Cakile maritima cover is statistically higher on beaches with medium levels than those with low or high levels of impact. However, the total cover of all species is not significantly different between any level of impact.
We conducted habitat, germination, and population genetic studies to inform management priorities for Phacelia cookei Constance & Heckard (Boraginaceae), a diminutive annual herb known from only four populations near Mt. Shasta in Siskiyou Co., California. Habitat surveys characterized soil, vegetation, and ground cover of extant populations and attempted to identify potentially suitable, but uncolonized, habitat. We were unable to distinguish any sites based on tests of soil characteristics. Nama densum Lemmon occurred at all sites where P. cookei was present. We identified several areas near existing populations that appeared to be suitable, but uncolonized, habitat. We tested the effects of various factorial combinations of after-ripening, scarification, stratification, and variable germination temperatures on breaking seed dormancy. Seed viability by tetrazolium tests ranged between 89% and 93%, but the highest germination from any treatment combination was 14% after adjusting for seed viability. We resolved 19 putative allozyme loci, two of which were polymorphic. Apparent genetic diversity was low both within and among the three sampled populations compared to similar endemic species, and populations were genetically similar. Management plans could consider attempting to expand existing populations by sowing seeds from existing populations into similar habitat.
Cryptantha wigginsii I.M. Johnston (Boraginaceae) had previously been known from a single collection made in April 1931, at a locality 18 miles south of Tijuana, Baja California, Mexico. This species is distinctive and unique in the genus in having nutlets with a surface that is smooth and glossy near the base and densely tuberculate at the apex. Because of the absence of subsequent collections, the species was presumed extinct. However, a population of C. wigginsii was recently discovered in Carlsbad, San Diego Co., California, constituting a new county, state, and country plant species record. Subsequent field investigations and study of (mis-identified) Cryptantha specimens at several California herbaria has turned up additional documented populations of this species in the USA and coastal northwestern Baja California, Mexico. In addition to the three adjacent Carlsbad populations and the type locality in Baja California, populations known to date include: 1) five from Santa Catalina Island, Los Angeles Co.; 2) one from Riverside Co.; and 3) three from northwestern Baja California. Cryptantha wigginsii is commonly found in, but apparently not restricted to, clay soil. Although additional populations may be found now that the taxon has been rediscovered, it is rare enough to warrant future listing as a sensitive and rare plant. Appropriate measures should be taken to preserve existing populations, some of which may be in danger of extirpation. The identification of vouchers of this species from existing herbarium collections highlights the need for depositories of plant collections and for their continued study by taxonomists and systematists.
Cryptantha martirensis M. G. Simpson & Rebman is described as new, being endemic to high elevations of the Sierra de San Pedro Mártir of Baja California, Mexico. It is sparse to common in the understory of coniferous woodland and in montane arroyos, slopes, and ridges in sandy to gravelly granitic substrates. This new species is similar to C. muricata (Hooker & Arnott) A. Nelson & J. F. Macbride in having nutlets with a shallow, dorsal ridge. It differs from the three recognized varieties of C. muricata in having a combination of tall and virgate primary stems with short and clustered inflorescence units; stems with mostly appressed and a few sparse, fine, spreading trichomes; a small corolla limb; and relatively large nutlets with dorsal tubercles that are low, rounded, and few per area. Quantitative evidence justifying these differences is summarized.
Monardella eplingii Elvin, A. C. Sanders, & J. L. Anderson (Lamiaceae), a new species from the Black Mountains of northwestern Arizona is described and illustrated. This new species is similar to M. arizonica Epling, M. eremicola A. C. Sanders & Elvin, M. robisonii Epling, M. mojavensis Elvin & A. C. Sanders, M. boydii A. C. Sanders & Elvin, M. linoides A. Gray subsp. linoides, and M. linoides subsp. erecta (Abrams) Elvin & A. C. Sanders. It differs from these taxa in leaf and bract morphology, pubescence on the stems and calyces, soil and geologic affinities, and distribution. A key is included for the Monardella of the eastern Mojave Desert region.