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Clammy Cuphea, Blue Waxweed, Tarweed
Cuphea viscosissima

Family: Lythraceae (ly-THRAY-see-ee) (Info)
Genus: Cuphea (KYOO-fee-uh) (Info)
Species: viscosissima (vis-kos-ISS-ih-muh) (Info)
Synonym:Cuphea petiolata
Synonym:Parsonsia petiolata




18-24 in. (45-60 cm)


Unknown - Tell us


Not Applicable

Sun Exposure:

Full Sun

Sun to Partial Shade


Unknown - Tell us

Bloom Color:

Magenta (Pink-Purple)

Bloom Time:

Late Spring/Early Summer

Mid Summer

Late Summer/Early Fall



Other details:

This plant is attractive to bees, butterflies and/or birds

Average Water Needs; Water regularly; do not overwater

This plant may be considered a protected species; check before digging or gathering seeds

Soil pH requirements:

5.6 to 6.0 (acidic)

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

7.6 to 7.8 (mildly alkaline)

7.9 to 8.5 (alkaline)

Patent Information:

Unknown - Tell us

Propagation Methods:

From seed; direct sow outdoors in fall

From seed; winter sow in vented containers, coldframe or unheated greenhouse

From seed; stratify if sowing indoors

Seed Collecting:

Collect seedhead/pod when flowers fade; allow to dry

Properly cleaned, seed can be successfully stored


This plant has been said to grow in the following regions:

Richmond, California

Elsberry, Missouri

Millersburg, Pennsylvania

Gardeners' Notes:


On Oct 19, 2008, BlueBarnLdy from Elsberry, MO (Zone 5a) wrote:

I bought this plant on a whim at a native plant sale. I was not impressed at first, but in mid summer it grew into a compact globe shaped plant with masses of tiny purple flowers. It produces LOTS of seeds, so I'm a little concerned about it self-seeding too much. Would be great in a rock garden where a low mounding plant is desired.


On Jan 29, 2006, Equilibrium wrote:

First off, this is a rather attractive plant with interesting flowers. Allegedly, this plant is currently being tested for any possible cancer fighting properties it might have so I'd say to leave this plant alone if you ever find it growing in the wild.