Unit 61 (061)

1. Euphorbia or Spurge

Euphorbia is a large genus of over 1,600 species found throughout the world. Many

have milky sap in the stems and leaves. Some of them grow in very dry areas and

have very fleshy ribbed stems that resemble a cactus. Many or them are poisonous

if eaten. Like the Poinsettia (Euphorbia pulcherrima), many have showy bracts or

modified leaves at the base of the inflorescence.

Euphorbia has a cyathium, a cup-like structure in which the flowers are borne.

Euphorbia maculata or Prostrate spurge, is a low growing weed that grows in high traffic

areas and sidewalk cracks. It has pubescent stems and milky sap.

Euphorbia cyparissias or Cypress spurge is a perennial that grows in banks,

roadsides, and cemeteries. Often considered a weed, it is a tough ground cover, and

there have been some cultivars selected.

Euphorbia epithymoides or Cushion spurge is a showy perennial with yellow bracts in

the spring.

Another hardy perennial is Euphorbia myrsinites, which has stout blue gray stems, and

rounded blue gray leaves arranged in a tight spiral around the stem.

2. Linum or Flax

Linum or flax is the source of linen fibers (Linum usitatissimum), and showy perennials

which typically have blue flowers on a thin wiry stem with small, grass-like leaves.

A bed of perennial flax (Linum perenne) looks like the blue flowers are almost floating

in the air, much like some of the Cosmos cultivars.

3. Ricinus communis or Castor Bean

Castor beans are tropical perennials that are grown as annual in Michigan. The purple

leaved types were common in your grandmothers garden. The large flat seeds are

poisonous, but were used for years in botany and biology classes to illustrate the

parts of a seed. Now it is considered too dangerous to use them in classes. These

attractive plants will grow to 5 or 6 ft. tall in one season.

4. Tropaeolum or Nasturtium

Nasturtium is the common name for Tropaeolum majus, but the genus Nasturtium

is watercress.

Tropaeolum leaves can be used in salads and have a slight peppery taste. It’s easy

to remember how to grow Tropaeolum. Just be nasty to nasturtiums.