Tropical Blood Weed

Posted by on June 18, 2009 at 9:50 am.
Tropical Blood Weed - Scarlet Milk Weed

Tropical Blood Weed - Scarlet Milk Weed

I was introduced to this plant as a “Tropical Blood Weed” but it’s one of those that goes by many names including Scarlet Milk Weed, bloodflower, silkweed, Indian root, and Mexican Milk Weed.  Maybe it’s easiest to talk about this plant using its scientific name, Asclepias curassavica.

In the tropics, this particular asclepias would be an evergreen sub-shrub, but in my neck of the woods it acts as an incredibly drought tolerant annual.  Typical of milkweeds, it has opposing leaves and a milky sap.  This particular milkweed reaches about 3 to 4 feet tall and its tall narrow profile allows it to fit in nicely almost anywhere.

Also typical of milkweeds, it is a favorite of nectar loving inscest including butterflies, especially the monarch who lays her eggs on it. In fact, this is one of the plants that allowed my certification as a monarch waystation.

The bloodweed also comes with its own unique bright yellow aphids that suck the sap from the stems and leaves.  It doesn’t appear to be life threatening, and the aphids draw more ladybugs.  They are also easily washed off with a blast of water.

In the fall, long spindle shaped pods split open and release a mass of silky threads or filaments with seeds attached.    The filaments were actually used during Word War II as an insulator and to fill life jackets.  Several filament carry each seed on the wind and they reseed readily in the garden, but don’t seem terribly aggressive.

One important tip:  all milkweeds are poisonous!  The milky sap contains alkaloids, latex and cardenolides, which defends the plants from being eaten.  The insect which have developed the ability to digest the plant are also poisonous.  That is why the monarch butterfly is poisonous to most birds.  But, not only is the sap poisonous, it can also be a skin irritant so be sure to wear your gloves when handling it.  That shouldn’t keep you from having it in your garden though.

-- Weather When Posted --

  • Temperature: 81°F;
  • Humidity: 69%;
  • Heat Index: 84°F;
  • Wind Chill: 81°F;
  • Pressure: 29.94 in.;


Leave a Reply