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Keyword: Asteraceae

Deep sequencing of amplicons reveals widespread intraspecific hybridization and multiple origins of polyploidy in big sagebrush (Artemisia tridentata, Asteraceae)

Publications Posted on: January 07, 2013
Premise of the study: Hybridization has played an important role in the evolution and ecological adaptation of diploid and polyploid plants. Artemisia tridentata (Asteraceae) tetraploids are extremely widespread and of great ecological importance. These tetraploids are often taxonomically identified as A. tridentata subsp. wyomingensis or as autotetraploids of diploid subspecies tridentata and vaseyana.

Effect of fungicides on Wyoming big sagebrush seed germination

Publications Posted on: October 03, 2012
Germination tests of Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young [Asteraceae]) seeds often exhibit fungal contamination, but the use of fungicides should be avoided because fungicides may artificially inhibit germination.

Specialist Osmia bees forage indiscriminately among hybridizing Balsamorhiza floral hosts

Publications Posted on: October 04, 2011
Pollinators, even floral generalists (=polyleges), typically specialize during individual foraging bouts, infrequently switching between floral hosts. Such transient floral constancy restricts pollen flow, and thereby gene flow, to conspecific flowers in mixed plant communities.

Taxonomic and nomenclatural rearrangements in Artemisia subgen. Tridentatae, including a redefinition of Sphaeromeria (Asteraceae, Anthemideae)

Publications Posted on: October 03, 2011
A recent molecular phylogenetic study of all members of Artemisia subgenus Tridentatae, as well as most of the other New World endemic Artemisia and the allied genera Sphaeromeria and Picrothamnus, raised the necessity of revising the taxonomic framework of the North American endemic Artemisia.

Optimal seeding depth of five forb species from the Great Basin

Publications Posted on: September 25, 2009
Use of forbs in revegetation projects in the Great Basin is limited due to high seed cost and insufficient understanding of their germination and establishment requirements. We tested the effects of seeding depth from 0 to 25.4 mm (1 in) on emergence and survival in clay and sandy loam soils of 5 ecologically important forbs. Significantly less emergence occurred of gooseberry-leaf globemallow (Sphaeralcea grossulariifolia (Hook. &.

Ecology and management of diffuse knapweed (Centaurea diffusa Lam.)

Publications Posted on: April 08, 2009
A close relative of spotted knapweed in the Asteraceae taxonomic family, diffuse knapweed is typically biennial, reproducing exclusively by seed. It forms a rosette with a central crown and tap root in the juvenile stage and a single upright stem one to three feet (0.3 to 0.9 m) tall with numerous spreading branches at maturity. White (occasionally purple) flowers are borne in heads with spiny bracts (see Figure 1).

Wildland shrubs of the United States and its territories: Thamnic descriptions, Volume 1

Publications Posted on: April 13, 2007
A discussion of the general characteristics of shrubs as a life form and their distribution within the United States is followed by 311 short monographs containing general descriptions, ranges, ecology, reproductive habits, growth and management, and benefits to humans, animals, and the environment.

Cytogeography and chromosome evolution of subgenus Tridentatae of Artemisia (Asteraceae)

Publications Posted on: June 22, 2006
The subgenus Tridentatae of Artemisia (Asteraceae: Anthemideae) is composed of 11 species of various taxonomic and geographic complexities. It is centered on Artemisia tridentata with its three widespread common subspecies and two more geographically confined ones. Meiotic chromosome counts on pollen mother cells and mitotic chromosome counts on root tips were made on 364 populations (X = 3.1 plants per population).