10. Galium pedemontanum (Bellardi) All.
Cruciata pedemontana (Bellardi) Ehrend.
Pl. 548 h, i;
Map 2544
Plants annual.
Stems 5–40 cm long, relatively weak, variously erect to loosely ascending or
clambering, unbranched or few-branched from near the base, evenly and sparsely
to densely pubescent with relatively long, straight, spreading, slender hairs,
usually also roughened with minute, prickly, downward-curved hairs on the
angles. Leaves 4 per node, weakly ascending to spreading or downward-angled
(with age) in orientation. Leaf blades 3–10 mm long, 1.5–5.0 mm wide, narrowly
elliptic to elliptic or lanceolate, the smaller ones occasionally ovate,
rounded or angled to a bluntly or sharply pointed tip, the midvein not extended
into a point, rounded or angled at the base, not glandular, hairy along the
midvein on the undersurface, with only the midvein visible, the margins with
relatively long, spreading to ascending, slender hairs, flat or only slightly
curled under. Inflorescences axillary from all but the lowermost leaves,
pendant, hanging below and largely covered by the leaves, consisting of
solitary flowers or more commonly small clusters or fascicles. Flowers (1)2 or
3, the stalks 1–2 mm long. Corollas 0.4–0.6 mm long, 4-lobed, yellowish green
to pale yellow. Fruits 1.0–1.5 mm long, 1–2 mm wide, the surface glabrous, smooth
to granular. 2n=18. April–July.
Introduced,
scattered, mostly south of the Missouri River (native of Europe, Asia; eastern
U.S. west to Kansas and Texas, also northwestern U.S.). Upland prairies,
glades, ledges and tops of bluffs, bottomland prairies, upland prairies, sand
prairies, margins of ponds, and fens; also pastures, old fields, margins of
crop fields, cemeteries, lawns, ditches, railroads, roadsides, and open
disturbed areas.
This species is
sometimes placed in the segregate genus Cruciata L., which includes
about 16 species native mainly to the Mediterranean region. Cruciata is
is said to differ from Galium in its combination of leaves 4 per node
and mixed perfect and imperfect flowers that are yellow, pendulous, and
generally held below the leaves. However Cruciata is here considered to
represent merely a specialized group within Galium. Morphologically, G.
pedemontanum is similar to the native G. virgatum; their
distinctions are discussed under that species. It shows marked morphological
variation locally, probably in response to microenvironment. Most notably it
varies from short-stemmed plants with the leaves relatively large and the nodes
about a leaf-length apart, to quite lanky plants with the leaves rather small
and the nodes well-separated. Plants of G. pedemontanum also change
markedly in general aspect near the end of their lives: as the last fruits
mature, the leaves quickly dry and sometimes become oriented downward.
This species is
a relative newcomer to the United States. It was first reported from Kentucky
(Bartholomew, 1941). Its rapid spread was documented by Sanders (1976), who
also reported it for the first time from Missouri. Since that time, it has
become increasingly common in the southern half of the state and is now likely to
be present in every county south of the Missouri River. It has also begun to
make inroads in northern Missouri.