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Seed development
Although follicles quickly reach mature size, seed development is not
necessarily complete. Seed is a translucent white in the early stages
and gradually darkens to a deep brown when mature. Pictures to the
left and below illustrate the various maturation stages of the seed in
follicles. |
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Follicle characteristics
Follicles vary widely in shape, size, color, and external
texture. The follicle shape may be elongated or short and round.
The color may appear green, yellow-green, or slightly purple. The
texture may range from the uncommon smooth surface to extremely long spines.
The picture to the right illustrates the phenotypic assortment collected
from the Alternative Crops Research plots. |
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Species comparisons
Current studies at WIU are focusing on
Illinois native common milkweed, Asclepias syriaca. However, several of
the populations used in the 2001 direct seeding trials were Asclepias
speciosa, showy milkweed, or hybrids achieved when A. syriaca
and A. speciosa are naturally cross-pollinated. The blooms of
both species are shown to the left and below as well as a comparison of
the flower sizes and structures of common milkweed, showy milkweed, and
the hybrid of the two.
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Monarch life cycle
Milkweed plants are host to monarchs at many stages of their
life cycle. Caterpillars feed on milkweed leaves prior to attaching to
the milkweed stalk to form their chrysalis. Butterflies return to
milkweed flowers after emerging from the chrysalis. Photographs to the
right and below show three stages of the monarch life cycle observed at the
Western Illinois University Agriculture Field Laboratory in Macomb, Illinois
throughout the 2003 season. |
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