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Michaux's Sumac

Rhus michauxii




Rhus_michauxii
Rhus_michauxii_colony
Rhus_michauxii_leaf



Michauxii's sumac_habitat.jpg
Rhus_michauxii_stem



Status under the U.S. Endangered Species Act

Federally Endangered (September 28, 1989)

State Heritage Status Rankings

Georgia (S1), North Carolina (S2), South Carolina (SX), Virginia (S1)




 

Description:

Michaux's sumac or false poison sumac is a densely hairy shrub, with a low stature, with erect stems which are mostly 0.3 to 0.6 m in height. Michaux's sumac forms dense clumps when in healthy populations. Both the young twigs and the leaves are densely hairy. The compound leaves are divided into 7 to 13 leaflets originating from a hairy rachis (axis) which, may be narrowly winged near the apex. Each leaf is finely to coarsely toothed on its edges. The leaflets are 4 to 9 cm in length, 2 to 5 cm width, oblong to oblong-lanceolate, sessile, sharply pointed at the apex, rounded at the base, dull on the upper surface of the leaf, veiny, and slightly hairy on their bottoms. The shrub's compound leaves are narrowly winged at their base. Individual plants are either male or female (dioecious). The flowers are arranged in dense, terminal panicles and have 4 to 5, tiny, greenish-yellow to white petals and are 4 to 5 parted. The flowers and fruit of male plants are solitary while the flowers on a female plant are grouped in 3 to 5 stalked clusters. Flowering is between April to August depending on weather conditions and habitat. From approximately August to November, a deep red, densely hairy fruit (drupe) is produced and is 5 to 6 mm in diameter (USFWS 2003 and Patrick et. al. 1995).

Habitat:

Michaux's sumac is shade-intolerant, inhabits sandy or rocky open woods (USFWS 2003) highway rights-of way, roadsides, or on the edges of artificially maintained clearings (Patrick et. al. 1995) and rights-of-way in association with basic (USFWS 2003) to circumneutral soils (NatureServe, 2003). Apparently, this plant survives best in areas where some form of disturbance has provided an open area (Patrick et. al. 1995). Although roadside occurrences appear to be thriving in the presence of some level of disturbance (i.e., mowing), they are always under the constant threat of catastrophic disturbance. Roadbed widening or heavy equipment activity on cleared lands, for example, may dramatically reduce the number of individuals (NatureServe 2003).

Range:

Michaux's sumac is endemic to the inner Coastal Plain and lower Piedmont of Georgia, the Carolinas, and Virginia, where it is currently known from about 26 extant occurrences (NatureServe 2003). The USFWS (2003) reports the species was once known from three States, Georgia, South Carolina, and North Carolina, this plant now has viable populations only in North Carolina. Just four plants still survive in Elbert County, Georgia. Previously, this plant was known from five Georgia counties: Cobb, Columbia, Elbert, Newton, and Rabun. Reintroduction efforts are underway at some of the historic sites. In South Carolina, two populations of the plant were historically known; now, the plant is considered extirpated from that State. Currently, the plant survives in the following North Carolina Counties: Richmond (6 populations); Hoke (3 populations); Scotland (2 populations); Franklin (1 population); Davie (1 population); Robeson (1 population); and Wake (1 population). It has been eliminated from Durham, Moore, Orange, Randolph, Wilson, Lincoln, and Mecklenburg counties. Of the 15 existing populations in North Carolina, nine have less than 100 plants each, and three of these have less than a dozen plants each. NatureServe (2003) reports that in 1993 a large, prolifically fruiting population was discovered on U.S. Army lands in Virginia, and the Army is now actively protecting the plants. Overall, however, the species has been in decline. In the 100 years following its discovery in 1895, half of all the historic occurrences were extirpated, largely due to habitat conversion to agriculture and other uses. Other on-going threats include the nearly universal suppression of natural fires within this species' range, hybridization with other species, geographic fragmentation and isolation of small, single-sex populations, and the potential for accidental destruction of roadside and other vulnerably situated populations (USFWS 2003).






References

  • NatureServe. 2003. Internet resource. NatureServe.

  • Patrick, T.S., Allison, J.R., and Krakow, G.A. 1995. Protected Plants of Georgia: AN INFORMATION MANUAL ON PLANTS DESIGNATED BY THE STATE OF GEORGIA AS ENDANGERED, THREATENED, RARE, OR UNUSUAL. Georgia Natural Heritage Program. Internet Resource. Protected Plants of Georgia.

  • Radford, A.E., Ahles, H.E., Bell, C.R. 1968. Manual of the Vascular Flora of the Carolinas. The University of North Carolina Press, Chapel Hill, North Carolina.

  • USDA, NRCS. 2002. The PLANTS Database, Version 3.5. Internet Resource USDA Plants Database. National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

  • US Fish and Wildlife Service (USFWS). 2003. Michaux's Sumac Species Account. Internet Resource:
    Michaux's Sumac Species Account
    (Accessed December 5, 2003)