Ask Mr. Smarty Plants

The monarch butterfly adults drink nectar from the flowers of many plant species, but the larvae feed exclusively on plants of the Family Asclepediaceae (Milkweed Family).  Generally, the larvae feed on plants in the Genus Asclepias, but will also feed on the vines in the Genera Matelea and Cynanchum.

Here are native species in the Family Asclepediaceae that occur in Bastrop, Gonzales and/or Travis Counties:

Asclepias amplexicaulis (Clasping milkweed) found in Bastrop County.  According to the Freckman Herbarium's Plants of Wisconsin its habitat is dry sandy prairies and woods.

Asclepias asperula (Spider milkweed) grows in all three counties in meadows, roadsides and brushlands.

Asclepias incarnata (Swamp milkweed) grows in Gonzales County in wet meadows and riparian areas.

Asclepias latifolia (Broadleaf milkweed) in Bastrop County grows in sandy, clayey or rocky soils of prairies according to MonarchWatch.

Asclepias linearis (Slim milkweed) grows in Bastrop County.

Asclepias oenotheroides (Zizotes milkweed) grows in Bastrop and Travis Counties and prefers dry sandy soils.

Asclepias texana (Texas milkweed) grows in Travis County in ditches, ravines, streams and river banks.

Asclepias tuberosa (Butterflyweed) grows in all three counties in prairies, openwoods, ravines and hillsides and prefers dry sandy soil.

Asclepias verticillata (Whorled milkweed) grows in all three counties in woodlands in rocky, sandy or clayey soils.

Asclepias viridiflora (Green milkweed) grows in Bastrop and Travis Counties in sandy or rocky prairie soils.

Asclepias viridis (Green antelopehorn) grows in all three  counties on roadsides and prairies in dry limestone soils.

Of these Asclepias species only A. incarnata and A. texana are indicated as growing near waterways.  The others could, however, be found in the general vicinity of rivers.

Although the Asclepias spp. are the primary food for monarch larvae, the following milkweeds may occasionally be used.

Cynanchum laeve (honey vine) grows in all three counties.  Here is more information from MonarchWatch.

Cynanchum racemosum var. unifarium (Talayote) grows in all three counties.

Funastrum crispum (Wavy-leaf milkweed vine) grows in Travis County.

Funastrum cynanchoides ssp. cynanchoides (Fringed twinevine) grows in Bastrop County.

Matelea biflora (Purple milkweed vine) grows in Travis County.

Matelea cynanchoides (Prairie milkvine) grows in Bastrop County.

Matelea edwardsensis (Plateau milkvine) grows in Travis County.

Matelea gonocarpos (Anglepod) grows in all three counties.

Matelea reticulata (Green milkweed vine) grows in Bastrop and Travis Counties.

Matelea sagittifolia (Arrowleaf milkvine) grows in Travis County.

Here is an information-filled brochure from Texas Monarch Watch about the monarchs in Texas and Texas Entomology has more on monarchs and milkweeds.