Boxwood family (Buxaceae)
Description: This plant is an evergreen perennial about 4-10" high that creeps along the ground, forming a dense ground cover. Individual stems are up to 12" long, light green, glabrous, and unbranched; they are erect toward their tips. Alternate leaves are spaced closely together toward the tips of the stems, forming pseudo-whorls. The leaf blades are 1-3" long and 1/3-1" across; they are oblanceolate in shape, dentate along the outer half of their margins, and rather stiff and leathery in texture. Each blade tapers gradually into a short petiole. The upper surface of the leaf blades is dark green and glabrous. Some stems terminate in solitary spikes of flowers about ¾–1½" long on short stalks. Japanese Pachysandra is monoecious. The typical floral spike has 15-25 staminate (male) flowers along its central and upper portions, and 1-2 pistillate (female) flowers at its bottom. The rachis (central stalk) of the floral spike is light green and glabrous. Individual staminate flowers are about 1/3" long, consisting of 4 appressed tepals and 4 prominent stamens. The tepals are light yellowish green, glabrous, and oval-ovate in shape; they are about 1/8" long. The thick filaments of the stamens are bright white and long-exerted. Individual pistillate flowers consist of 4-6 tepals and a pistil with a pair of styles. The blooming period occurs during the spring for about 1 month. The flowers are sweetly fragrant. Sometimes immature flowering spikes are produced during the fall, but they rarely bloom. Fertile female flowers produce small white berries about 1/3" across; however, such berries are rarely produced. The root system is rhizomatous, readily forming dense colonies of plants.
Cultivation: The preference is light shade, moist conditions, and rich loamy soil with organic matter. This plant can spread aggressively and it is difficult to remove. Excessive sunlight can cause the leaves to turn yellowish green.
Range & Habitat: While it is often cultivated, Japanese Pachysandra rarely escapes. So far, it has naturalized in DuPage County (see Distribution Map). It is possible that this plant may become more common in the future, particularly around urban areas. This plant was introduced into North America from China and Japan. Habitats in natural areas include deciduous woodlands and woodland edges.
Faunal Associations: Very little is known about floral-faunal relationships for this plant. Bees are attracted to the flowers during the spring, where they collect pollen; nectar is not produced. The foliage is toxic to mammalian herbivores and is rarely consumed; it contains cytotoxic alkaloids. The rarely produced berries are probably eaten by birds or small rodents, thereby distributing the seeds to new locations.
Photographic Location: Underneath a tree at the Independent Media Center in Urbana, Illinois.
Comments: Because of its attractive evergreen foliage, Japanese Pachysandra is cultivated primarily as a ground cover in shaded areas along buildings and underneath trees. The odd-looking flowers are also attractive, particularly when they are viewed close-up. There is a less well-known species, Pachysandra procumbens (Allegheny Pachysandra), that is native to wooded mountainous areas of eastern United States. So far, it has been found in southern Indiana, but not Illinois. Allegheny Pachysandra differs from Japanese Pachysandra in the following characteristics: 1) it has wider leaf blades that taper abruptly into petioles, and 2) it produces axillary flowering spikes from below, rather than terminal flowering spikes at the tips of stems. Sometimes these species in the Pachysandra genus are referred to as 'Japanese Spurge' and 'Allegheny Spurge.'