4. Galium asprellum Michx. (rough bedstraw)
Map 2538
Plants
perennial. Stems 15–120 cm long, spreading to loosely ascending or clambering,
usually much-branched, roughened with minute, prickly, downward-curved hairs on
and usually also between the angles, sometimes also pubescent around the stem
nodes with short straight hairs. Leaves 5 or 6 per node, mostly spreading to
very slightly ascending in orientation. Leaf blades 4–15 mm long, 1–5 mm wide,
lanceolate to narrowly lanceolate or linear, angled to a sharply pointed tip,
the midvein usually extended into a minute, sharp point, angled or truncate at
the base, the undersurface not glandular, glabrous, the venation with only the
midvein visible, the margins with short, stiff, prickly hairs and often somewhat
curved under. Inflorescences terminal and axillary from the upper leaves, not
pendant, positioned over the leaves, consisting of small panicles (occasionally
some of these reduced to simple clusters) with mostly 1–3 branch points and
short to relatively long, ascending branches. Flowers mostly several to
numerous, the stalks 1–5 mm long. Corollas 1.0–1.2 mm long, 4-lobed, white.
Fruits 0.8–1.0 mm long, 1.5–2.0 mm wide, the surface glabrous, smooth. August.
Uncommon, known
thus far only from a single, historical specimen from DeKalb County
(northeastern U.S. west to Wisconsin and Missouri; Canada). Habitat unknown,
but possibly bottomland forests (based on specimens from other states).
The presence of
this species in Missouri was first suggested without documentation by Gleason
(1952), but was not confirmed until the present research. Galium asprellum
can be distinguished vegetatively from some other Galium species by its
stem nodes that are surrounded with a ring of spreading pubescence. This
feature is also found in G. boreale, G. concinnum, G. obtusum,
and G. tinctorium. The Missouri collection represents an unusual,
somewhat disjunct, southwestern locality for G. asprellum. If more data
were available about the population from which it was harvested, a case could
be made that the species represents a relict in Missouri, surviving from
glaciated times when our state had a cooler climate.