4. Euphorbia cyparissias L. (cypress spurge, graveyard spurge)
Map 1666, Pl.
380 a, b
Plants perennial
herbs, with a fleshy rootstock and usually rhizomes. Stems 15–40 cm long, erect
or ascending, unbranched below the inflorescence or often with several short,
densely leafy vegetative branches in the median and upper leaf axils, the
branches not flattened toward the tip, usually green to yellowish green,
sometimes reddish- or purplish-tinged toward the base, glabrous. Leaves
alternate below the inflorescence branches (those of the inflorescence branches
usually opposite) but closely spaced (crowded, especially toward the stem tip),
sessile. Stipules absent. Leaf blades 10–30 mm long, unlobed, the margins
entire, the surfaces glabrous, yellowish green to green; those below the
inflorescence linear to narrowly oblanceolate, rounded or angled at the base,
mostly angled or short-tapered to a sharply pointed tip; those along the
inflorescence branches broadly ovate to nearly heart-shaped or somewhat
kidney-shaped, rounded to cordate at the base, mostly broadly angled to a
sharply pointed tip. Inflorescences terminal umbellate panicles with a whorl of
leaves at the base and with each of the up to 10 primary branches sometimes
branched 1 or 2 additional times, the cyathia solitary at the branch tips.
Involucre 2–3 mm long, glabrous, the rim shallowly 4-lobed to nearly entire,
the marginal glands 4, 0.8–1.3 mm long, crescent with each end appearing as a
short, outward-curved horn, greenish yellow to yellow, lacking a petaloid
appendage. Staminate flowers 15–25 per cyathium. Ovaries glabrous, but the surface
pebbled or minutely warty, the styles 0.5–1.0 mm long, each divided 1/5–1/4 of
the way from the tip into 2 somewhat club-shaped lobes. Fruits produced in
relatively few cyathia, 2.5–3.0 mm long, glabrous but the surface pebbled or
finely warty, especially toward the sutures. Seeds 1.5–2.0 mm long,
oblong-elliptic in outline, nearly circular in cross-section, rounded or
somewhat angled at the base, the surface smooth, grayish brown to silvery gray,
with a small, nipplelike caruncle. 2n=20, 40. April–August.
Introduced,
scattered to uncommon, mostly in counties adjacent to the Missouri and
Mississippi River floodplains (native of Europe, Asia, introduced widely but
sporadically in the U.S., Canada). Glades, ledges and tops of bluffs,
bottomland forests, and edges of mesic upland forests; also cemeteries,
gardens, railroads, and roadsides.