False poison sumac is a rare deciduous shrub, esteemed for its clusters of cream-colored flowers and vibrant red autumn foliage. Thriving in sandy woodlands, its low-growing, colony-forming habit showcases resilience against wildfires, embellished by distinctive red berries that beckon birds. This hardy species is a beacon of survival and regeneration in its native habitat.
I. Appearance and Characteristics
Rhus michauxii is a rare species of flowering plant in the cashew family known by the common names false poison sumac and Michaux’s sumac. It is endemic to the southeastern United States, where it can be found in the states of Virginia, North Carolina, South Carolina and Georgia. It is threatened by the loss and degradation of its habitat and by barriers to reproduction. It is a federally listed endangered species of the United States.
This plant is a small shrub growing 30 to 60 centimetres (12 to 24 in) tall. It is very hairy in texture. The small size and hairiness distinguish the plant from other sumacs. The long leaves are each made up of several pairs of toothed leaflets. The plant is dioecious with male and female reproductive parts occurring on separate plants. The plant produces an erect inflorescence of white or greenish yellow flowers in June that develop into red drupes in female plants in late summer to early fall. This plant was first described as Rhus pumila by André Michaux in 1803, and it was renamed for Michaux in 1895.
This shrub grows in wooded areas often on clay or decomposed granite soils. It occurs in sandhills habitat in loamy soils. The habitat may be dominated by longleaf pine and oaks and it may grow alongside Ceanothus americanus, Paspalum bifidum, Tridens carolinianus, Aristida lanosa, Onosmodium virginianum, and Helianthus divaricatus. Other associates and indicators of the plant include Liquidambar styraciflua, Cornus florida, Rhus glabra, R. copallinum, Schizachyrium scoparium Sorghastrum elliottii, Brickellia eupatorioides, Eupatorium godfreyanum, E. sessilifolium, Silphium compositum, Helianthus divaricatus, Helianthus strumosus, Viburnum rafinesquianum, Scleria oligantha, Clematis ochroleuca, Sanicula smallii, Salvia urticifolia, and Parthenium auriculatum. The area is generally somewhat more moist than surrounding habitat types. The plant requires openings in the vegetation so it can receive sunlight.
Half of the recorded populations of this plant have been extirpated. Much of its habitat has been cleared for residential, industrial, and agricultural operations, including silviculture, and the construction of roads. Remaining habitat is degraded by the lack of a normal fire regime. The plant does not tolerate shade and it grows naturally in openings maintained by wildfire. Today, fire suppression is practiced and normal periodic wildfires are prevented. The result is overgrowth of the vegetation, which shades out the rare shrub.
This plant also has difficulty reproducing. It is clonal, often reproducing vegetatively, so populations are low in genetic variability. It may hybridize with the common Rhus glabra. This union forms Rhus × ashei, a natural hybrid. One major reproductive problem is that many populations are composed entirely of one sex. Furthermore, the populations are small and very widely spaced, making reproduction impossible. As the plant requires open habitat, it may arise in artificially cleared areas such as roadsides. There it is vulnerable to destruction from construction, maintenance, and herbicides.
Conservation activities include genetic analysis in an effort to understand the genetic variability of populations. Plant propagation techniques are being studied. Plants are being reintroduced to appropriate habitat, including the placement of opposite-sex plants into single-sex populations. Plants are transplanted from high-risk areas to better habitat for their survival. Prescribed burns help to create openings where the plant can thrive.
II. How to Grow and Care
False poison sumac is a somewhat demanding plant, necessitating close attention to its moisture and light needs. It thrives in well-drained soil and requires partial to full sunlight exposure. Special care should be taken with its watering schedule to maintain consistent soil moisture without waterlogging, which can lead to root rot. Adapting to its sensitivity to environmental conditions is paramount for successful cultivation.
Sunlight
False poison sumac prefers full sun, but can also be grown in slight shade. It is recommended to plant it in a more open location that can provide it 6 or more hours of sunlight per day. When it gets adequate light, its leaves turn beautiful bright red or orange-yellow in fall.
Temperature
False poison sumac is distributed throughout temperate and subtropical regions, and prefers warm, humid conditions. It is hardy to cold and can tolerate low temperatures of -7 ℃. False poison sumac can tolerate some drought but not standing water, so do not plant it in low-lying locations. In rainy seasons or locations, pay attention to soil drainage to prevent root rot.
Watering
Thriving in its native environment, false poison sumac has adapted to regular rainfall patterns, necessitating watering every week to mimic these conditions. This species exhibits a moderate tolerance for drought but prefers consistent moisture to support its growth and vitality. For indoor cultivation, false poison sumac benefits from being placed in an area with stable humidity levels to reflect its natural habitat’s climate. As a deciduous plant, false poison sumac’s water needs fluctuate with the seasons, requiring less hydration during its dormancy period in colder months.
Soil
False poison sumac is adaptable and can grow in many types of soil. It prefers slightly acidic to neutral soil of pH 5.5-7.5, but can adapt to mildly alkaline soil. False poison sumac can grow in poor gravelly soil under drought, but naturally, rich, fertile and well-drained soil is better for its growth.
Fertilizing
False poison sumac can tolerate poor soils, but adequate fertilizer will promote its growth and produce flourishing foliage. Before planting, thoroughly mix organic fertilizer into the soil to enrich the soil nutrients.
Right after planting, an application of urea once in spring promotes growth and reduces the risk of pests and diseases. An application of phosphorus-potassium-rich fertilizer in early summer promotes flowering. You can also use an organic fertilizer once in late fall to provide nutrients for the winter. Avoid using a large amount of fertilizer once; although it promotes the growth of false poison sumac, it can result in increased susceptibility to pests, diseases, and frosts in winter.
Planting Instructions
Transplant false poison sumac before it sprouts in spring or after leaves falling in fall. Start by digging a pit in a sunny, elevated place. The pit should be as deep as the height of the root ball, and wider than its width. These dimensions give the roots enough space to grow. Once planted, compact the soil and water deeply. Generally, the plant doesn’t need watering again after new buds sprout.
Pruning
False poison sumac does not require much pruning. Pruning some of the lower and side branches in winter to early spring is fine. During this period, false poison sumac grows slowly, so pruning has less impact on the tree. Not only does pruning reduce wasted nutrients and promote plant growth, but it also helps the emergence of strong new branches in the following year, as well as gradual crown renewal. In daily maintenance, prune branches that are dry, overgrown, or infected with pests and diseases.
Propagation
Native to North America, false poison sumac is a rare deciduous shrub prized for conservation and restoration efforts. To propagate false poison sumac, cuttings prove effective, with emphasis on selecting healthy, semi-ripe stems. Cut sections just below a leaf node, ensuring each piece boasts several nodes. For rooting, a well-draining medium supplemented with rooting hormone encourages successful establishment. Under optimal humidity and temperature, cuttings require consistent monitoring for moisture and fungal threats, ensuring a steady transition to maturity.
Transplanting
For false poison sumac, optimal transplant success is achieved during the period of vigorous growth, from late spring to summer’s cusp. Seek spots with partial to full sun and moist, well-draining soil. Ensure gentle handling to protect delicate roots.
III. Harvesting and Storage
Collect false poison sumac seeds in the fall when the fruits turn red. Collect, wash, and dry the seeds and store them in a dry, cool place.
