Shrub lespedeza (Lespedeza bicolor)

Synonyms: Lespedeza penduliflora, Lespedeza setiloba, Lespedeza ionocalyx, Lespedeza spicata, Lespedeza tobae, Lespedeza veitchii, Lespedeza patentibicolor, Desmodium penduliflorum

Common Names: Bicolor lespedeza, shrub bushclover, shrubby lespedeza

Description:

Shrub lespedeza (Lespedeza bicolor) is a shrub in the pea family, native to temperate parts of China, Korea, and Japan [1][6][7]. It reached the United States in 1856 as an ornamental, and from the 1930s onward federal and state wildlife agencies handed out millions of seeds and seedlings for erosion control, mine reclamation, and bobwhite quail habitat [1]. MISIN tracks it because those deliberate plantings spread on their own into open ground, where it forms dense thickets that crowd out other plants [3].

Habit:

Shrub lespedeza is an upright, loosely branched shrub that reaches about 5 to 10 feet tall and roughly as wide [1][2]. Its leaves are divided into three oval leaflets, each about three-quarters of an inch to two inches long, blue-green on top and paler underneath, each ending in a sharp point [1][2]. The stems are erect and gray-green [2].

Late summer is the easiest time to find it. From June through September it carries pink to purple pea-shaped flowers, each about half an inch long, in loose clusters 2 to 5 inches long near the tops of the stems [1][2]. Flowering peaks in August and early September [3]. Winter is the second-best time to spot it: the plant drops its leaves but its stiff brown upright stems stand through the cold months, so old thickets stay obvious against bare ground [3]. Flat little pods hang on from August into March [2].

At-a-glance cues:

1. Multi-branched shrub 5 to 10 feet tall and about as wide [1][2]
2. Leaves split into three blue-green leaflets, each under two inches long [1][2]
3. Pink to purple pea flowers in loose 2 to 5 inch clusters, mid to late summer [1][2][3]
4. Flat pods about a third of an inch long, each holding a single black seed [1][2]

Leaves:

1. Arrangement: alternate along the stem, and deciduous (dropped each fall) [1]
2. Structure: divided into three leaflets [1][2]
3. Shape: oval to elliptical, tapering to a sharp point at the tip [1][2]
4. Margin: smooth and unbroken [2]
5. Size: leaflets 0.75 to 2 inches long, about two-thirds as wide as long [1][2]
6. Color: blue-green above, noticeably lighter on the underside [2]

Stems:

1. Habit: a multi-branched shrub reaching 5 to 10 feet tall and about as wide [1][2]
2. Form: erect and loosely branched, with an open, somewhat arching outline [2]
3. Color: gray-green [2]
4. Diameter: stems at the root crown may reach about 1.2 inches (3 cm) across [1]
5. Roots: a heavy, much-branched root system spreading roughly 4 feet wide and 2 feet deep [1]
6. Winter: leafless brown upright stems stay standing through the winter [3]

Flowers:

1. Color: pink to purple [2]
2. Shape: pea-like, about 0.5 inch long [1]
3. Arrangement: loose clusters 2 to 5 inches long, each holding 5 to 15 flowers [1]
4. Position: on the upper portion of the stems, at stem tips and leaf joints [1][2]
5. Bloom time: June through September, peaking in August and early September [2][3]

Fruit and seeds:

1. Fruit type: a flat pod that does not split open on its own, holding a single seed [1]
2. Size: up to about 8 mm (roughly a third of an inch) long [1][2]
3. Seed: one black seed per pod [2]
4. Ripening: pods mature in October or early November, and remain on the plant from August into March [1][2]
5. Dispersal: seeds drop gradually through fall and winter, mostly falling close to the parent plant under their own weight [1][3]
6. Seed coat: roughly 28 to 85 percent of fresh seeds are hard-coated and must be scratched or weathered before they will sprout [1]

Habitat:

Shrub lespedeza is native to temperate areas of China, Korea, and Japan [1]. It is not native to North America ? every plant here traces back to a deliberate planting or its offspring [1].

In the United States it grows in old fields, thickets, savannas, pine forests, woodlands, and along creek banks [1]. It also takes hold on disturbed ground: clearings, meadows, pastures, roadsides, and embankments [1]. Open, sunny, recently disturbed sites suit it best.

It grows in full sun to partial shade and prefers well-drained ground, but it copes easily with poor, dry soil and drought [2]. That toughness is exactly why it was promoted for erosion control and reclamation in the first place [1].

Its foothold is strongest in the southeastern United States [1]. In some regions it is not rated as a severe threat and generally needs disturbed ground before it can establish [1].

Reproduction:

Shrub lespedeza spreads mainly by seed, and it makes a great deal of it. Plants start producing seed at 3 to 4 years old, and dense stands can produce on the order of 300 million seeds per acre [1]. Most of that seed simply drops under its own weight and lands close to the parent plant, which is why this species tends to thicken in place rather than jump long distances [1]. North Carolina State Extension reports that birds and small mammals also move the seed [2].

The seed is the hard part of the problem. A large share of it is hard-coated and will sit in the soil until something scratches the coat open [1]. That seed bank is long-lived ? seed has been reported to stay viable after decades in the ground [1]. So clearing the visible plants does not end the job.

The plant also comes back from its own roots. When it is cut, mowed, or burned off at ground level, it sprouts again from the root crown, the woody knot where stem meets root [1][3]. A single cut usually produces regrowth rather than a kill.

For timing, the useful window is before the pods ripen. Pods mature in October or early November, and seed then drops gradually through fall and winter [1]. Cutting or pulling plants before October keeps that year's seed out of the soil.

Impact and Damage:

For a homeowner, the practical problem is space. Shrub lespedeza forms dense thickets that push out whatever was growing there before [3]. Where stands get thick ? on the order of 50,000 shrubs per acre ? they stop grasses from growing and prevent young trees from establishing [1]. On a property with an old field, a fence line, or a woodlot edge, that means a patch steadily converting to solid lespedeza. No toxicity to people, pets, or livestock was reported in the sources reviewed for this sheet.

For natural area stewards, the concerns are native plant cover, forest regeneration, and wildlife habitat, all of which can be degraded in heavily invaded areas [1][3]. In southern forests the species is estimated to occupy about 115,550 acres, with nearly 50,000 of those acres in Georgia and Arkansas [1].

How solid is this evidence? Less solid than the acreage figures suggest, and it is worth being straight about that. The USDA Forest Service notes that most descriptions of this plant's harmful effects on vegetation, wildlife habitat, and land management are anecdotal, and that detailed study of dense stands is lacking [1]. Assessments also vary by region: in parts of the Southeast it is treated as a severe threat to native plant communities, while in other regions it is not rated severe and usually needs disturbed ground to get started [1]. Treat it as a species worth controlling early and worth reporting, rather than one with a thoroughly measured impact record.

Similar species:

Two other lespedezas tracked by MISIN are easily mixed up with this one, and the differences are straightforward once you know what to check.

Chinese lespedeza (Lespedeza cuneata) is the easiest to separate, because it is not really a shrub ? it is a herbaceous perennial 3 to 6 feet tall with gray-green hairy stems that may turn slightly woody with age [4]. Its leaflets are narrow and oblong, 1 to 3 inches long but under an inch wide, with a silvery cast from dense flattened hairs [4]. The flowers settle it: they are tiny, about a quarter inch, and creamy white to pale yellow with a purple spot in the center ? not the pink-to-purple half-inch flowers of shrub lespedeza [2][4].

Thunberg's lespedeza (Lespedeza thunbergii) is the harder call, since it is also a shrub with pink to purple pea flowers and blue-green three-part leaves [5]. Look at size and shape first: it forms a smaller fountain-like mound of arching stems, 3 to 6 feet tall and wide, rather than the taller upright habit of shrub lespedeza [1][2][5]. Then check the flower clusters, which are the clearest cue ? Thunberg's carries its flowers on long clusters about 6 inches, roughly double the 2 to 5 inch clusters of shrub lespedeza [1][5].

Monitoring and rapid response:

Signs to watch for:

1. Dense shrubby thickets in old fields, along roadsides and fence lines, and at the edges of pine woods [1]
2. Pink to purple pea flowers in loose clusters from June through September, heaviest in August [2][3]
3. Stiff brown leafless stems standing through winter, marking old patches when everything else has died back [3]
4. Flushes of seedlings on ground that has recently been cleared, dug, or burned [1]

What you can do:

1. Pull young plants when the soil is damp and they come up whole. This is the highest-value work you can do, because plants do not start setting seed until they are 3 to 4 years old ? removing them first stops the seed bank from growing [1].
2. Cut or mow before October. Pods ripen in October or early November, so cutting ahead of that keeps a whole year of seed out of your soil [1].
3. Expect it to come back and plan return visits. Cutting alone triggers sprouting from the root crown, but heavy, repeated cutting does reduce cover over time [1][3]. One pass will not do it.
4. Dig out the root crown on individual shrubs. The woody knot at the base is what resprouts, so getting it out is the point of digging. Roots run about 4 feet wide and 2 feet deep, so plan for real effort on a mature plant [1].
5. Do not burn it. Fire top-kills the stems but drives sprouting from the root crown, and its heat cracks the hard seed coats so buried seed germinates ? burned sites repeatedly come back thicker than unburned ones [1]. One forestry handbook states outright that fire is not a control option for this species [1].
6. Do not plant it, and discourage new plantings nearby. Prevention remains the most effective approach, and this shrub is still sometimes sown for wildlife cover [1].
7. For a natural area crew: hit small outlying patches before the large core stand, since those outliers are what expand the infestation's footprint. Then commit to long-term monitoring ? seed stays viable in the soil for decades, so a site is not finished when the last shrub is gone [1].

When to call a professional:

1. Large or long-established thickets, where hand-cutting will produce a wall of root crown sprouts rather than a reduction [1]
2. Sites where repeated cutting over several seasons has not shrunk the stand [1]
3. For chemical control options, contact a licensed applicator or your local cooperative extension office.

Report sightings to MISIN. Help track this species' spread by submitting observations through the MISIN web site or the MISIN mobile app (Android, iOS, Windows, and macOS). Photos at multiple angles paired with a precise GPS location are the most valuable data for confirming new occurrences and triggering rapid-response review.

Credits:

1. Munger GT (2004). Lespedeza bicolor. In: Fire Effects Information System (FEIS). U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. fs.usda.gov
2. North Carolina Extension Gardener Plant Toolbox. Lespedeza bicolor (Bicolor Lespedeza, Shrub Bushclover). NC State Extension. plants.ces.ncsu.edu
3. Texas Invasives. Shrubby lespedeza, Lespedeza bicolor. texasinvasives.org
4. North Carolina Extension Gardener Plant Toolbox. Lespedeza cuneata (Chinese Bushclover, Sericea Lespedeza). NC State Extension. plants.ces.ncsu.edu
5. North Carolina Extension Gardener Plant Toolbox. Lespedeza thunbergii (Thunberg's Lespedeza). NC State Extension. plants.ces.ncsu.edu
6. Plants of the World Online. Lespedeza bicolor Turcz. Royal Botanic Gardens, Kew. powo.science.kew.org
7. Integrated Taxonomic Information System. Lespedeza bicolor Turcz., TSN 25895. itis.gov

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