nodding spurge

not listed

N5 - Secure

SNR - Unranked

not listed

FACU - Facultative upland

FACU - Facultative upland

FACU - Facultative upland

Nodding spurge is a low, spreading, 3″ to 12″ tall, annual forb that rises from a taproot. All parts of the plant emit a milky sap when broken.

The stems are thick, round, up to 32″ long, and frequently branched at the base. They are ascending or erect, never prostrate. They are usually ascending, sometimes just at the branch tips. They are tan or pinkish-tan, becoming reddish in strong sun. They are sparsely to moderately covered with curved hairs toward the stem tips and around the nodes. Older parts of the stem are hairless or nearly hairless. Sometimes the hairs occur in two lines on opposite sides of the stem. The plant does not root at the nodes.

Leaves are opposite, oblong or oblong egg-shaped, and stalkless or on very short leaf stalks. The leaf blades are 5 ⁄16″ to 1½″ long about a third as wide. They are bluntly-pointed at the tip, rounded and asymmetrical at the base. The base of the blade on one side is expanded into a small, rounded, ear-like projection (auricle). The upper and lower surfaces are usually sparsely to moderately hairy near the base, sometimes hairless. The upper surface is deep green, often with a reddish spot near the middle. The lower surface is pale green but is not covered with a whitish, waxy bloom (glaucous). The margins are finely toothed.

What appear to be flowers are actually false flowers (cyathia) common to the Euphorbiaceae (spurge) family. The inflorescence is usually a small, leafy cluster of cyathia, sometimes a single cyathium, rising from a leaf axil.

The cyathium is less than ⅛″ wide. It is on a stalk up to ⅛″ long. There are no petals or sepals. A single floral bract is formed into a hairless, 1 ⁄32″ long cup (involucre). There are 4 white or pinkish, spreading, petal-like lobes at the tip. There are 5 to 28 male flowers and a single female flower in the cyathium. The male flower has 1 stamen. The female flower has a 3-valved, hairy, seed capsule hanging alongside the involucre.

The fruit is a 3-lobed, hairy capsule with 3 seeds.

3″ to 12″

White or pinkish

Spotted spurge (Euphorbia maculata) stems are prostrate. The plant is usually less than 1″ tall.

Prostrate knotweed (Polygonum aviculare) does not emit milky sap from broken stems and leaves. It has a sheath that surrounds the stem above each leaf axil.

Dry to moist. Pastures, fields, open woods, lawns, gardens, and disturbed sites. Full sun.

June to October

Sources

2, 3, 4, 5, 7, 28, 29, 30.

Native

Nodding spurge was formerly classified as Chamaesyce nutans. Species were originally assigned to the genus Chamaesyce based on the structure of the reproductive organs. Genus wide molecular studies in 2002, 2006, 2007, and 2010 have all unequivocally placed them in the genus Euphorbia, where they were subsequently transferred.

Plant

Inflorescence

Leaf Underside