The Florida Native Plant Society shared this on Facebook and I thought it was really interesting. Didn't know if any South Floridians might be able to help...


Can you help me, please, to obtain information in the possible expansion of Asclepias asperula from the traditional distribution
(http://plants.usda.gov/core/pr...).

Let me explain my interest in this. I work on the migration of the
monarch butterfly, Danaus plexippus. I use Thin Layer chromatography (TLC) to determine the larvae butterfly host plant. We recently found monarchs with the Asclepias asperula fingerprint, meaning that they hatched in the southwest of the United States. These butterflies were caught in south Florida, close to Miami. This means that these butterflies hatched in the southwest of the United States and then migrated (?) through the Florida peninsula. However, we are puzzled about this result because migrant monarchs that hatched in southwest
United states will probably go to Mexico and not South Florida.

This "unusual" result can be explained by the expansion of Asclepias asperula from their known distribution. I found information of the effect of global warming on Asclepias asperula, explaining its possible expansion. In addition, this species is popular with some American and Canadian gardeners as a way to attract butterflies, including the monarch butterfly. But because there is an unofficial ban in growing A.asperula beyond its traditional areas it has been difficult obtaining information. My interest is purely academic and any reports can be done without a name. In addition, the future publication of these results could
be critical in the protection of the monarch. There are very few studies of the migrant monarchs in Florida.

I will be happy to send you my papers if you wish and/or you can Google them. Does anyone have, please, any records of the presence of this species apart from their known distribution? if yes, (1) can you tell me where and when this species was observed; (2) Did you see any monarch larvae and/or adult in A.asperula?; (3) how many A. asperula plants did you see (I only need a rough estimation)?and (4) any pictures available?

Thanks for helping the monarchs and all the best.

Cristina Dockx
[email protected]

Very interesting! I'm in a traditional area for A. asperula, so can't help with that. Quite a few A. asperula plants died during the absolute worst of the very prolonged drought around here, in spite of them being very drought-hardy plants. The rest of them are still going, fortunately. We are in severe drought at present.

I find it fascinating that they can test Monarchs to find out what kind of plant they ate as a caterpillar. That is so cool!