Eastern Redbud - Cercis canadensis
Family: Fabaceae (Leguminosae)
Eastern redbud is a small, short-lived deciduous tree found throughout the eastern United States.
Height: 15-20' Spread: 18-25' Growth Rate: Medium. Hardiness Zone: 4 to 8
 


Eastern Redbud

Two subspecies of redbud have been identified: Texas redbud (Cercis canadensis var. texensis) found in southern Oklahoma, Trans-Pecos Texas, and southeastern New Mexico; and Eastern redbud (C. canadensis var. canadensis) found in the remainder of the range. Another native Cercis species, California redbud (C. occidentalis), is found in Utah, Nevada, California and Arizona.

Redbud is a regular but usually not a common understory component of many forest types throughout the Eastern United States. It is not a commercial timber species, and although it grows in many forest cover types, it is not listed in all of them by the Society of American Foresters. This forest-edge tree needs sunlight to produce its namesake blossoms, yet it will suffer in full summer heat. Redbuds grow best in part shade in well-drained soils high in organic matter. The shallow root system will benefit with a 3-4-inch layer of organic mulch. Redbuds vary in hardiness; buy from a local or regional source.

Purplish-pink buds occur along the branches in early May. Dark green, heart-shaped leaves turn a nice yellow fall color. The brownish-black bark on older trees often has an inner orange-red coloration. Distinct zigzag branching pattern on new growth. They make wonderful specimen plants especially with evergreen masses, thus providing contrast for the floral display and supplying the recommended protection from intense sunlight.

Flowering and Fruiting- Redbud flowers are pink to reddish purple, and rarely white. They are home on pedicels in clusters of two to eight. Flowers are produced from small buds on old twigs, branches, and trunks. Flowers are bisexual and the tree is self-pollinating. Flowering usually occurs sometime from March to May and precedes leafing. In Indiana, the tree requires 30 days of temperatures averaging more than 10° C (50° F) . Previous winter chilling also enhances flowering (11). Pollination is usually accomplished by bees. After 2 or 3 weeks leaves appear and the flowers drop. The ovaries of one to several flowers in most flower clusters enlarge and develop into fruits that reach their full size by midsummer. Fruits are flat reddish-brown pods about 1.3 cm (0.5 in) wide and 5 to 10 cm (2 to 4 in) long. Each fruit contains 4 to 10 brown, hard, compressed bean-like seeds, each about 6mm (0.25 in) long. The fruits remain on the tree until after leaf fall; some persist throughout winter.


Winter-persitent redbud fruit

Seed Production and Dissemination- Seeds are released by the opening of fruit sutures or decay of the fruit wall. Most seeds are dispersed during fall and winter by wind and animals. Many seeds are injured by insects. Those that fall to the ground usually remain dormant for several years.

 

 

Rooting Habit- Redbud develops a deep taproot that descends rapidly the first few years if the soil permits. Initial growth depends on soil moisture and the absence of a tight clay subsoil. If impenetrable subsoils are present the taproot grows horizontally. Secondary roots appear when the taproot is 5 to 8 cm (2 to 3 in) long and grow rapidly. Reaction to Competition- As redbuds grow and mature they become less shade tolerant. Old trees usually suffer from heart rot and cannot normally tolerate severe competition and shade. Redbud is most accurately classed as tolerant of shade.


Redbud Foliage and Fruit


Heart-shaped Redbud Leaves

Damaging Agents- Redbud is a host to a variety of insects, but damage is not normally severe. Bark and phloem borers include three species of Hypothenemus, and Pityophthorus lautus. A seed beetle, Gibbobruchus mimus, breeds in the seed of redbud. Numerous wood borers have been found in redbud. Agrilus otiosus, three species of Hypothenemus, three species of Micracis, two species of Microcisella, Pityophthorus lautus, Ptosima gibbicollis, and Thysanoes fimbricornis all inhabit portions of the wood of redbud.

Other insects feed on the leaves of redbud. The redbud leaffolder, Fascista cercerisella, feeds on leaves which the larvae web together. The grape leaffolder, Desmia funeralis, an important pest of grape, also feeds on redbud. The Japanese weevil, Callirhopalus bifasciatus, and Norape ovina both consume redbud leaves. Other insects feed on redbud by extracting juices from the plant. The twolined spittlebug, Prosapia bicincta, has been recorded feeding on redbud. The terrapin scale, Mesolecanium nigrofasciatum, and San Jose scale, Quadraspidiotus perniciosus, like most of the other redbud parasites, inhabit a variety of hosts including redbud. The periodical cicada, Magicicada septendecim, lays its eggs in more than 70 species of trees and other plants, including redbud.

There are three main diseases of redbud: leaf anthracnose, Mycosphaerella cercidicola, Botryosphaeria canker, and Verticillium wilt. The most serious is the canker Botryosphaeria ribis or its variety chromogena. The species is mainly a saprobe; the variety is a parasite. This variety produces stem and twig lesions and entire groves of redbuds have been killed by this disease. Verticillium wilt (Verticillium albo-atrum) sometimes kills redbuds, especially in the Midwestern United States. Redbud is vulnerable to Texas root rot (Phymatotrichum omnivorum), but redbud is not commonly grown in its range. A variety of sap and heart rots also infect eastern redbud.

Special Uses
The eastern redbud is extensively planted as an ornamental throughout the Eastern United States. It is tolerant of a wide range of site conditions, is not especially vulnerable to insects or diseases, is relatively easy to maintain, and makes a beautiful shrub or small tree, especially when flowering. Bark of redbud has been used as an astringent in the treatment of dysentery. Flowers of the tree can be put into salads or fried and eaten. There is some documented wildlife use of redbud fruit. Cardinals have been observed feeding on the seeds, and seeds have been consumed by ring-necked pheasants rose-breasted grosbeaks, and bobwhites. White-tailed deer and gray squirrels have also been observed feeding on the seeds. Flowers of the tree are regarded as important in the production of honey by bees.
--From USFS Hardwoods, Volume 2

MORE TrEES

 

              
 
       web       www.cirrusimage.com