Beach layia can also occur in narrow bands of moderately disturbed habitat along the edges of trails and roads in dune systems dominated by invasive species. Coastal dune systems are composed of a mosaic of vegetation communities of varying successional stages. Beach layia occurs in early to midsuccessional communities in areas where sand is actively being deposited or eroding. Too much sand movement prevents plants from establishing, but areas with some movement on a periodic basis support early successional communities. Movement of sand by wind is essential for the development and sustainability of a dune system. Wind is also important to beach layia specifically because it is the mechanism by which seeds are dispersed. The achenes (a small, dry, one-seeded fruit that does not open to release the seed) have pappus (feathery bristles) that allow them to be carried by wind for a short distance. Although not all seeds may land on suitable habitat, this adaptation allows the small annual to spread across the landscape into uninhabited areas. As a winter germinating annual, beach layia requires rainfall during the winter months (November through February) for germination and, although it is relatively tolerant to the droughtlike conditions of upland dunes, it does need some moisture through the spring to prevent desiccation. Moisture also reduces the risk of burial, as dry sand is more mobile and mortality caused by burial has been documented. The overall resource needs that beach layia requires in order for individuals to complete their life cycles and for populations to maintain viability are: (1) Sandy soils with sparse native vegetation cover, (2) Rainfall during the winter germination period, (3) Sunlight (full sun exposure for photosynthesis), and (4) Unknown degree of crosspollination (to add to genetic diversity). References External links Jepson Manual Treatment USDA Plants Profile Elkhorn Slough Species Profile Photo gallery US Department of Interior Rulemaking Docket Regulations.gov carnosa Endemic flora of California