• GENERAL BOTANICAL CHARACTERISTICS
• RAUNKIAER LIFE FORM
• REGENERATION PROCESSES
• SITE CHARACTERISTICS
• SUCCESSIONAL STATUS
• SEASONAL DEVELOPMENT

GENERAL BOTANICAL CHARACTERISTICS:

Smooth sumac is a native, perennial, deciduous, thicket-forming shrub or small tree that grows from 2 to 20 feet (0.5 to 6 m) [78]. Branches tend to be fairly sparse, smooth, and stout [36]. The flowers are borne in long (up to 18 inches (45 cm)), dense, compound, terminal panicles [44]. The fruit is a small drupe containing a single small seed [10]. Smooth sumac has a high tannin content [40].

Smooth sumac thickets are often connected by branched rhizomes [89]. The main roots grow to depths of 7 to 8 feet (2.1-2.4 m) and give rise to many smaller roots. The dense network of main roots, relatively shallow laterals, and rhizomes promotes increased utilization of soil moisture and rapid vegetative spread. Rhizomes reach to a depth of 3 to 12 inches (7.6-30.5 cm) [19,90].

In a detailed study of 13 clones of smooth sumac in Michigan and Ohio, Gilbert [34] drew several major conclusions, including the following: Stems range from 1.3 to 9.8 feet (0.4-3m) in height and 1 to 15 years in age, with the tallest stems being the oldest. Fifty-six percent of observed floral buds did not develop completely to the flowering or fruiting stage. One clump was shown to be a vegetative development of a single individual. A single clone may cover as much as an area 72 × 131 feet (22 × 40 m). Average annual spread of a clone is 37.6 inches (94 cm), and a stem may arise from a rhizome several years old.

RAUNKIAER LIFE FORM:

Phanerophyte

REGENERATION PROCESSES:

Li and others [37] report that the 1.5 months required for flower, fruit and seed development in smooth sumac is much faster than that reported for other members of the Anacardiaceae family. Flowers may develop into conspicuous red fruits after only 6 weeks.

Smooth sumac produces at least some seed nearly every year [16]. The seeds are widely distributed by many species of birds and mammals [26]. There is evidence that seeds persist in the soil seedbank [1,6]. Smooth sumac seed has averaged up to 97% sound, depending on the lot examined [50]. Germination is inhibited by the hard, impervious hull and seedcoat [37,41,50]. Brinkman [16] observed that germination was greatest and most rapid under continuous light. A constant temperature regime of 68 degrees Fahrenheit (20 ^oC) and alternating warm and cool temperatures both promoted good germination, whereas a constant temperature of 95 degrees Fahrenheit (35 ^oC) prevented germination.

Smooth sumac also readily reproduces vegetatively. It spreads through rhizomes to form large, dense thickets [16,45]. The rhizomes may produce new shoots as far as 30 feet (1-9 m) from the parent plant [90].

SITE CHARACTERISTICS:

Smooth sumac grows in a wide range of habitats including open woodlands, prairies, dry rocky hillsides, canyons, and protected ravines [36,40,90]. It often forms dense thickets in prairies [89]. It is common in ecotonal areas and is often found along roadsides, in dry waste areas, and in old fields [36]. Smooth sumac grows well on shallow to moderately deep, dry to moist, coarse or variably textured soils. It grows best on slightly acidic to neutral soils (pH 6.5-7.0) with sunny exposures [78].

Smooth sumac occurs as high as 2290 meters in Utah [91].

SUCCESSIONAL STATUS:

Smooth sumac is a climax indicator in a number of shrub and grassland communities [22,32,84]. Three vegetation associations typified by smooth sumac are found on colluvial or alluvial soils in canyons in the Columbia Basin Province described in Franklin and Dyrness [32]; Their understories are dominated by bluebunch wheatgrass (Pseudoroegneria spicata), sand dropseed (Sporobolus cryptandrus), or red threeawn (Aristida purpurea). Daubenmire [22] identified these 3 hypothetical climaxes, but concluded that grazing effectively reduced them to a smooth sumac/cheatgrass community. The patchy distribution of smooth sumac stands in the Washington steppe and their restriction to sandy soils warrant designating them as one or more edaphic climaxes.

Smooth sumac is a prominent species in prairie and oak savanna communities where fire has been suppressed [38,49,80,83]. It is relatively intolerant of shade [90].

In a 1981 central Oklahoma tallgrass prairie studied for old field succession following different initial plowing treatments beginning in 1949, vegetation development in 4 hypothesized stages from pioneer weeds to mature prairie was heterogeneous and unpredictable. Smooth sumac was present in unplowed plots and also appeared in the other 2 plots that developed to mature prairie following one 1949 plowing and 5 annual plowings from 1949 to 1953. The authors [20,21] characterize the succession to mature prairie as "very rapid," at least in part due to continual fire suppression. They predict that woody shrubs, including smooth sumac and flameleaf sumac (Rhus copallina), Chickasaw plum (Prunus angustifolia), and coralberry (Symphoricarpos orbiculatus) will continue to increase, and the upland forest trees post oak (Quercus stellata) and blackjack oak (Q. marilandica ) may eventually dominate the site. The authors note that in the absence of fire, mature prairie vegetation is not the climax on the coarse textured soils of the region, and that fire is essential to maintenance of tallgrass prairie. Please note, however, that the Fire Effects section of this report discusses a number of prescribed burns, especially in the spring, which increased smooth sumac.

SEASONAL DEVELOPMENT:

Smooth sumac renews growth early in the year [89], with flowers developing before the leaves [86]. Flowering dates are as follows [26]:

Location    Beginning of Flowering    End of Flowering

CO          May                       July
MT          July                      July
ND          July                      July
UT          May                       July

Fruit ripens from September to October [16]. Seed often persists through the fall and winter [78].

Related categories for SPECIES: Rhus glabra | Smooth Sumac