SafePlants

Milkweed: A Vital Plant for Monarch Butterflies

Milkweeds (Asclepias species) are a crucial component of the North American ecosystem, particularly as the host plant for monarch butterfly larvae. This article explores various aspects of milkweed, with a focus on species found in Florida and their importance to monarch conservation.

Considerations for Pets

• Milkweeds contain cardiac glycosides, which are stored within the plant.

Scientific Names and Common Names

• Accepted Scientific Name: Asclepias (various species)
• Common Names: Milkweed, Scarlet Milkweed, Tropical Milkweed, Butterfly Milkweed, Sandhill/Pinewoods Milkweed, Clasping Milkweed, Florida Milkweed, Swamp Milkweed, Bloodflower, Silkweed, Indian Root, Orange Milkplant, Butterfly Milkplant

Taxonomy and Nomenclature

• Family: Asclepiadaceae (implied, as Asclepias is the genus name)
• Examples of Species:
  • Asclepias curassavica (Scarlet Milkweed or Tropical Milkweed)
  • Asclepias humistrata (Sandhill/Pinewoods Milkweed)
  • Asclepias tuberosa (Butterfly Milkweed)
  • Asclepias curtissii (Curtiss' Milkweed)
  • Asclepias amplexicaulis (Clasping Milkweed)
  • Asclepias feayi (Florida Milkweed)
  • Asclepias perennis (Swamp Milkweed)

Distribution and Habitat

• Milkweeds are widely distributed across the United States, with approximately 73 native species.
• Florida is home to 21 native milkweed species, with 8 native species in South Florida.
• Specific native regions include Alabama, Arizona, Arkansas, Colorado, Connecticut, Delaware, Florida, Georgia, Idaho, Illinois, etc.
• Asclepias curtissii is endemic to Florida's sandy areas.
• Asclepias curassavica is found in fields and disturbed areas throughout the world, including central and southern Florida.

Ecological Role

• Milkweeds are essential larval host plants for monarch butterflies (Danaus plexippus).
• Monarch butterfly populations are declining, in part due to declining milkweed populations and habitat destruction.
• Some sources suggest that the non-native Asclepias curassavica (Tropical Milkweed) may contribute to parasite infections in monarchs, especially in regions like South Florida where it can grow year-round.

Morphological Characteristics and Growth Habits

• Mention is made of 'bright orange flowers' of Asclepias curassavica.

Interactions with Other Organisms

• Monarch caterpillars (larvae of Danaus plexippus) can defoliate a milkweed plant quickly.
• Queen caterpillars also feed on milkweed in southern states, particularly Florida.

Resources and Further Information

• Florida Native Plant Society
• Atlas of Florida Plants
• Florida Museum of Natural History
• Xerces Society
• Live Monarch Foundation (seeds available)
• Florida Wildflowers Growers Cooperative