1. Trichophorum planifolium (Spreng.) Palla (bashful bulrush)
Pl. 83 h–j; Map 332
Isolepis planifolia Spreng.
Scirpus planifolius Muhl. (1817),
not S. planifolius Grimm (1767)
S. verecundus Fernald
Plants perennial, forming dense clumps,
glabrous, frequently with the previous year’s dried herbage persisting around
the base. Aerial stems many per plant, 9–40 cm long, erect to spreading or
arched, slender, unbranched, sharply triangular in cross-section, minutely
roughened along the angles, glabrous, the sides finely longitudinally grooved.
Leaves alternate along the lower third of the stems, the lowermost leaves
reduced to bladeless sheaths. Leaf sheaths light brown to pale green, the inner
side papery, usually torn or convex at the tip, the ligule a short, white
ridge. Leaf blades (of the uppermost leaves) mostly as long as or longer than
the stems, 0.5–1.5 mm wide, spreading to ascending or more commonly arched,
flat. Inflorescences terminal, composed of 1 spikelet, the involucral bract 1,
similar in appearance to the bracts of the spikelet, not leaflike or stemlike,
erect, 2–8 mm long, ovate, the midrib extended past the main body of the bract
as an awn. Spikelets 4–7 mm long, 1.5–2.0 mm in diameter, ovate in outline,
usually pointed at the tip. Florets 4–8 per spikelet, in an overlapping spiral
pattern, perfect. Spikelet scales 3.0–4.5 mm long, ovate, the tips rounded to
pointed, pale green to orangish brown, the midrib thickened and extended past
the main body of the scale as a short awn, usually green. Perianth bristles
3–6, unequal, shorter than to longer than the fruit. Stamens 3. Styles not
expanded at the base during flowering, not forming a tubercle. Stigmas 3.
Ovaries and fruits naked, without a perigynium (saclike covering). Fruits oblong-elliptic
in outline, unequally 3-angled, somewhat flattened, broadly concave on the side
facing the spikelet axis, the surface finely pebbled, light brown to dark
reddish brown, often somewhat iridescent. 2n=92. April–May.
Scattered in the eastern half of the Ozark
Division (northeastern U.S. and adjacent Canada south to Virginia and Missouri). Rocky slopes of mesic to dry upland forests on chert or sandstone substrates;
less commonly in bottomland forests and along creek banks.
Although once thought to be rare in Missouri, this species has proven to be fairly common in the eastern Ozarks, as was
predicted by Steyermark (1963). It is a characteristic species of acidic soils
on dry, forested, chert or sandstone slopes, particularly on relatively steep,
north-facing ones. Plants are often overlooked in the field, both because the
herbage somewhat resembles that of the more widespread Carex albicans
and because the inflorescences shatter quickly after the fruits ripen. Further
field work will undoubtedly reveal the presence of this species in more