What May be Limiting Reproduction and Viability of Mead’s Milkweed?

Missouri Botanical Garden

Provided by Christy Edwards and Matthew Albrecht

Missouri Botanical Garden is conducting a research project with the Center for Plant Conservation (CPC) on the species Mead’s milkweed (Asclepias meadii). This species is endemic to tallgrass prairies and listed as federally threatened on the Endangered Species Act. It is a long-lived perennial plant that occupies mature tallgrass prairie habitats in Kansas, Missouri, Iowa, and Illinois. The goal of the project is to understand whether a genetic bottleneck or low genetic variation is limiting reproduction and the overall viability of the species. Genetic data from this study will help inform ongoing restoration and conservation efforts with this species.

The initial decline of the species was due to habitat loss and adverse land management practices. Low fecundity was a factor in preventing recovery of the species. Some populations produced only a few or no seed pods each year. This seemed to vary among populations — some populations did successfully produce seed pods each year, but others produced none. It is unknown whether populations that do not produce seed indeed have lower genetic diversity and higher relatedness than those successfully producing seed, or whether other unknown factors are affecting fecundity in Mead’s milkweed.

The Shaw Nature Reserve has created over 300 acres of prairie plantings: “The Reserve’s prairie plantings (on former farmland or pasture) represent this once-vast, nearly treeless ecosystem, of which less than 1% of the original remains intact . . . Prairie plants are introduced by direct seeding, and less often, greenhouse-grown transplants. The tall grasses, reaching as high as 10 feet, remind us of the ocean as they wave in a gentle breeze. Over 70 species of wildflowers bloom in the prairie beginning in May and ending in October. The leaves, stalks, and blossoms of these wildflowers present a fascinating variety of colors, shapes, and textures. Some species, such as goldenrods and sunflowers, spread across the prairie in bright yellow masses in late summer, while to discover other species may require more careful searching among the grasses.” Note: Asclepias meadii does not occur naturally at Shaw Nature Reserve, and it has not been successful at establishing an introduced population on the premises.

Learn more about the Shaw Nature Reserve here.

Meads milkweed

PHOTOS: Mead’s milkweed (Asclepias-meadii)

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By | 2018-06-20T17:38:35+00:00 June 15th, 2018|Featured Article|0 Comments

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