Nimblewill [Muhlenbergia schreberi J.F. Gmel.][MUHSC][CDFA list: B] Map of Distribution Photographs

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SYNONYMS:wire-grass, drop-seed

GENERAL DESCRIPTION:Spreading perennial to 0.5 m tall, with branched stems that root at the lower nodes. Although it is a widespread noxious weed of turf, pastures, orchards, and nurseries in the Central and Eastern U.S., nimblewill is a fairly new introduction with a limited distribution in California. Native to Eastern U.S., Texas, Eastern Mexico, and South America.

SEEDLINGS:Ligules and sheaths resemble those of mature plants. Blades ~25 mm long, 1-3 mm wide. Collar white, lacks long hairs on margins.

MATURE PLANT:Stems often grow prostrate at the base, rooting at the nodes, with terminal portions curved upwards (decumbent). Leaves rolled in bud. Blades short (3-9 cm long), 1.5-6 mm wide, flat, glabrous except for sparse long hairs near sheath. Ligules membranous, < 0.5 mm long, truncate, minutely toothed. Sheaths open, slightly flattened, membranous along margins. Auricles lacking. Collar region has a few long hairs near the margins at the position of the auricles.

ROOTS and UNDERGROUND STRUCTURES:Roots shallow, fibrous. Lower stems typically root at nodes, but do not form definite creeping stolons.

SPIKELETS/FLORETS:May-November. Panicles lax, often drooping, loosely flowered, 3-15 cm long, narrow (2-10 mm wide), with ascending to erect branches. Spikelets stalked, 1(2)-flowered, break apart above the glumes. Glumes 1 or 2, usually < 0.5 mm long. Lemmas ~ 2 mm long, 3-veined, sometimes purplish, tipped with an awn 1.5-5 mm long. Floret base (callus) with a tuft of short hairs. Caryopsis football-shaped, reddish-brown, ~ 1-1.5 mm long, shed with lemma and palea.

POSTSENESCENCE CHARACTERISTICS:Foliage turns brown in winter, but stems survive and resprout the following spring.

HABITAT:Primarily disturbed places, forest sites, and cultivated fields in California. Roadsides, landscaped areas, fields, orchards, nurseries, turf, and woodlands elsewhere. Grows best in damp, often shady places on moist, fertile soils.

DISTRIBUTION:Uncommon in California. Sacramento Valley (Sacramento Co, near border with Yolo Co.), northern and central Sierra Nevada foothills (Nevada, Mariposa cos.). To 1200 m (4000 ft). Also, central and eastern U.S., Canada.

PROPAGATION/PHENOLOGY:Reproduces by seed and vegetatively from lower stem nodes. Seed appears to require an afterripening period and germinates in spring. Light and cold, moist conditions (stratification) increase germination. Seed retained on parent plants through the winter can become dormant and unable to germinate the following spring.

MANAGEMENT FAVORING/DISCOURAGING SURVIVAL:Plants do not tolerate regular cultivation.

SIMILAR SPECIES:Bermuda grass [Cynodon dactylon (L.) Pers.] and creeping bentgrass [Agrostis stolonifera L.] have growth habits similar to nimblewill. Unlike nimblewill, Bermuda grass has ligules that consist of a ring of white hairs ~ 1 mm long, with a few longer hairs at the margin. Creeping bentgrass has rounded, membranous ligules 2-5 mm long, without hairs near the margins.