Tragopogon mirus and T. miscellus (both 2n = 4x = 24) are recent allotetraploids derived from T. dubius × T. porrifolius and T. dubius × T. pratensis (each 2n = 2x = 12), respectively. The genome sizes of T. mirus are additive of those of its diploid parents, but at least some populations of T. miscellus have undergone genome downsizing. To survey for genomic rearrangements in the allopolyploid...

On both recent and ancient time scales, polyploidy (genome doubling) has been a significant evolutionary force in plants. Here, we examined multiple individuals from reciprocally formed populations of Tragopogon miscellus, an allotetraploid that formed repeatedly within the last 80 years from the diploids T. dubius and T. pratensis. Using cDNA-AFLPs followed by genomic and cDNA cleaved amplifie...

Many studies have focused on the ecology of seed dimorphism, the production of two seed types by a single plant. Morphology and seed size are usually correlated, but how morphology affects germination percentage and seedling growth is poorly understood. Here we explicitly separate these effects for nine populations of the dimorphic species Tragopogon pratensis subsp. pratensis. Larger seeds yie...

Alimurgic species are edible wild plants growing spontaneously as invasive weeds in natural grassland and farmed fields. Growing interest in biodiversity conservation projects suggests deeper study of the multifunctional roles they can play in metal uptake for phytoremediation and their food safety when cultivated in polluted land. In this study, the responses of the tap-rooted perennial specie...

Lord Howe is an oceanic and relatively young island situated in an area of complex geological and therefore biogeographical processes. The island boasts a large number of endemic species, including many beetles, however, few groups are in an adequate state of systematic knowledge for biogeographic investigation. Recent advances in the systematics of the hyper-diverse rove beetle tribe Staphylin...

Tragopogon pratensis is a small herbaceous plant that uses wind as the dispersal vector for its seeds. The seeds are attached to parachutes that increase the aerodynamic drag force and increase the total distance travelled. Our hypothesis is that evolution has carefully tuned the air permeability of the seeds to operate in the most convenient fluid dynamic regime. To achieve final permeability,...

Dmitri Pavlov and Jakob Scholbach have pointed out that part of Proposition 6.3, and hence Proposition 4.28(a), of [2] are incorrect as stated. While all of the main results of that paper remain unchanged, this necessitates modifications to the statements and proofs of a few technical propositions.

For an old-growth forest edge in the Sierra Nevada, we quantified the extent of edge effects from a group selection harvest. Across transects from the interior of the old-growth forest through the group selection opening, we quantified changes in resource availability (light, soil moisture, and seedbed) and vegetation composition (cover, richness). We found a steep change in light availability ...

The invasion and spread of exotic plants following land disturbance threatens semiarid ecosystems. In sagebrush steppe, soil water is scarce and is partitioned between deep-rooted perennial shrubs and shallower-rooted native forbs and grasses. Disturbances commonly remove shrubs, leaving grass-dominated communities, and may allow for the exploitation of water resources by the many species of in...