Conocarpus erectus var. sericeus: Silver Buttonwood
Edward F. Gilman, Dennis G. Watson, Ryan W. Klein, Andrew K. Koeser, Deborah R. Hilbert, and Drew C. McLean
Introduction
This low-branching, multi-trunked, shrubby, evergreen tree has beautiful silvery leaves due to silky hairs which cover the leaf surface. The inconspicuous, small, greenish flowers appear in dense conelike heads in terminal panicles in spring and are followed by 1/2-inch, conelike, red-brown fruits. The dark brown attractive bark is ridged and scaly. The leaves are small and fall between the grass blades of the lawn or are easily washed away in the rain.
Figure 1. Full Form—Conocarpus erectus var. sericeus: Silver buttonwood Credit: Ed Gilman, UF/IFAS
Origin: native to Florida, the Caribbean, and South America
UF/IFAS Invasive Assessment Status: little invasive potential; not considered a problem species at this time and may be recommended by UF/IFAS faculty (reassess in 10 years)
Uses: specimen; street without sidewalk; screen; deck or patio; hedge; reclamation; parking lot island < 100 sq ft; parking lot island 100–200 sq ft; parking lot island > 200 sq ft; sidewalk cutout (tree pit); tree lawn 3–4 feet wide; tree lawn 4–6 feet wide; tree lawn > 6 ft wide; urban tolerant; highway median; bonsai; shade; container or planter
Figure 2. Range
Description
Height: 15 to 20 feet
Spread: 15 to 20 feet
Crown uniformity: symmetrical
Crown shape: vase, spreading
Crown density: moderate
Growth rate: moderate
Texture: fine
Foliage
Leaf arrangement: alternate
Leaf type: simple
Leaf margin: entire
Leaf shape: lanceolate, oblong
Leaf venation: pinnate
Leaf type and persistence: evergreen
Leaf blade length: 2 to 4 inches
Leaf color: blue-green to silvery gray
Fall color: no color change
Fall characteristic: not showy
Figure 3. Leaf—Conocarpus erectus var. sericeus: Silver buttonwood
Flower
Flower color: white
Flower characteristics: not showy
Flowering: year-round
Fruit
Fruit shape: round
Fruit length: < ½ inch
Fruit covering: dry or hard
Fruit color: purple-brown to red-brown
Fruit characteristics: does not attract wildlife; showy; fruit/leaves not a litter problem
Fruiting: year-round
Figure 4. Fruit—Conocarpus erectus var. sericeus: Silver buttonwood
Trunk and Branches
Trunk/branches: branches droop; showy; typically multi-trunked; no thorns
Pest resistance: free of serious pests and diseases
Use and Management
Capable of reaching a height of 40 feet with a 20-foot spread, silver buttonwood is often seen as a small, somewhat asymmetrical shrub but is ideal for use as a screen, clipped hedge, or specimen planting. Due to the attractive bark and soft foliage, a multi-stemmed specimen can make a nice patio or street tree. Planted in the open as a tree, silver buttonwood will grow to about 15 to 20 feet tall and will often take on a picturesque, contorted appearance when exposed to constant seashore winds, creating an attractive specimen. The crown is more symmetrical 1/2 mile or more from the coast or on the inland side of a tall ocean-front building. The wood of silver buttonwood was formerly used for firewood, cabinetwork, and charcoal making and is very strong. It is an ideal wood for smoking meats and fish.
A Florida native, silver buttonwood is ideal for seaside plantings as it is highly tolerant of full sun, sandy soils, and salty conditions. It also tolerates brackish areas and alkaline soils, thriving in the broken shade and wet soils of hammocks. This is a tough tree! It withstands the rigors of urban conditions very well and makes a durable street or parking lot tree. Due to its small size, plant on 15-foot centers to form a closed canopy along a street. Purchase single-trunked trees for street and parking lot plantings.
The cultivar 'Mombo' has a dense crown and may be smaller than the species, 15 to 20 feet tall. Conocarpus erectus (buttonwood) has green leaves and is a somewhat larger tree with a vase-like shape. Some sources lump the two trees together as Conocarpus erectus.
Propagation of silver buttonwood is by seed.
Pests
Sucking insect secretions will result in problems with sooty mold on trees inland from the coast.
Diseases
No diseases are of major concern.
References
Koeser, A. K., Hasing, G., Friedman, M. H., and Irving, R. B. 2015. Trees: North & Central Florida. Gainesville: University of Florida Institute of Food and Agricultural Sciences.
Koeser, A.K., Friedman, M.H., Hasing, G., Finley, H., Schelb, J. 2017. Trees: South Florida and the Keys. Gainesville: University of Florida Institute of Food and Agricultural Sciences.
