Lespedeza cuneata (Dum. Cours.) G. Don (sericea lespedeza, Chinese lespedeza)
Pl. 401 c, d; Map 1769
Plants perennial
herbs. Stem 50–150 cm long, 2–5 mm in diameter near the base, unbranched or branched above the midpoint, densely
pubescent with appressed to somewhat spreading hairs
mostly confined to conspicuous, white, longitudinal ridges running the length
of the stem. Primary leaves with the petiole 2–12 mm long (shorter toward the
stem tip), 0.3–0.5 mm wide, densely pubescent with appressed
or slightly spreading hairs. Stipules 2–8 mm long, hairlike. Leaflets 1–3 cm long, 2–6 mm wide (mostly
more than 3 times as long as wide), those of the uppermost leaves usually
smaller, narrowly oblanceolate to narrowly oblong,
narrowly angled or tapered at the base, truncate at the tip, but sometimes
shallowly notched and usually with an abrupt, minute, sharp point at the very
tip, often with a grayish appearance, both surfaces densely appressed-hairy
or the upper surface sometimes becoming glabrous. Axillary clusters of leaves
sometimes developed. Inflorescences axillary clusters of 1–4
flowers from the median and upper leaves, shorter than or nearly equal to the
associated leaves. Calyces with the tube 1.0–1.5 mm long, the lobes 2.5–4.0
mm long. Corollas 5–9 mm long, creamy white with purple
markings or markings on the banner, the keel about as long as the wings.
Fruits from open flowers 3.0–4.5 mm long, the calyx nearly
equal in length; fruits from cleistogamous flowers
2.0–3.5 mm long, the calyx slightly shorter than to somewhat longer than the
fruit. Seeds 1.5–2.0 mm long, olive green to brown.
2n=18, 20, 22. August–October.
Introduced, scattered to common nearly
throughout the state (native of Asia; introduced in the eastern U.S. west to
Nebraska and Texas, Canada). Upland prairies, loess hill prairies, glades,
banks of streams and rivers, and margins of ponds and lakes; also old fields,
mine spoils, quarries, railroads, roadsides, and open disturbed areas.
Although originally planted
for forage, erosion control, soil enrichment, and wildlife food, L. cuneata
escapes and readily invades native plant communities. The states of Kansas and
Colorado have designated this species a noxious weed and it is considered an
invasive exotic nearly everywhere that it grows in North America. The species
is difficult to control, especially in grassland communities, as it responds
well to the same environmental cues to which warm-season grasses and
summer-flowering forbs respond. It spreads easily along roadsides, and also as
a contaminant on road-grading equipment and farm combines. Until the recent
past, sericea lespedeza was still planted widely
following highway improvement projects, often in large monocultures. Lespedeza cuneata
is not known to hybridize with any of the native North American species.