Red osier dogwood

Red osier dogwood subspecies sericea, sometimes called American Dogwood, is an erect, perennial shrub that rises usually on multiple stems. It can be up to 13′ tall and up to 1¼″ in diameter, but is usually no more than 10′ in height. It rises from a shallow, branching, woody root system.

Its form is highly dependent on its habitat. When growing in full sun, numerous stems form a dense, compact, rounded shrub about as wide as it is tall; the individual stems have many lateral branches; and the leaves are thicker and smaller. When growing in shade, numerous stems form open sprawling shrubs with few branches, and the leaves are thinner and larger. When growing in a dense grassy area the stems tend to be solitary and unbranched.

Shrubs reproduce vegetatively in three ways. In a process called layering, shrubs produce stems that lie on the ground with only the tips ascending (decumbent). A decumbent stem roots at a node, produces an aerial stem, and eventually detaches, forming a new plant. Shrubs also produce aboveground runners (stolons) that root at the nodes and produce new plants. Stolons can be up to 10′ long. Finally, lower branches may droop to the ground, root at the tip, and send up a new shoot. Vegetative reproduction often results in dense thickets.

Stems may be erect, arched, or decumbent, and are usually branched toward the top. In a colony, the middle stems tend to be upright while those on the periphery are arched, forming a rounded clump.

First-year twigs are slightly hairy and and have a few raised, corky bumps (lenticels). They are dark red at first, sometimes green splotched with red, becoming greenish-red then grayish-green as the season progresses. They are not streaked or spotted. Second-year twigs are similar in color but hairless. In winter the twigs turn red. The common name of this plant refers to the color of the twigs in winter. The pith is white and solid. The leaf scars are narrow, U-shaped, and slightly raised. Each leaf scar has three bundle scars and is connected by a thin line to the leaf scar on the opposite side of the twig. The terminal bud is egg-shaped and is covered by two sharply pointed, abutting but not overlapping scales. The scales have whitish tips, appearing frosted. Lateral buds are similar but smaller.

The bark is red, greenish-red, or yellowish-green, becoming red in winter. Older bark is light brown and rough.

The leaves are opposite, deciduous, and evenly distributed along the branch. The leaf stalk is hairy and ⅜″ to 1″ long. The leaf blade is egg-shaped to elliptical, 2″ to 4⅓″ long, and 1″ to 2⅜″ wide. It is rounded or tapered at the base and tapered to a sharp point at the tip, usually with concave sides along the tip. On each side of the midrib there are usually 5 or 6, occasionally 7, conspicuous veins that curve upward toward the tip of the leaf. The veins are depressed on the upper leaf surface, giving the leaf a puckered appearance. The upper surface is dark green and covered with short, straight, appressed hairs; longer, soft, spreading hairs; or both. The lower surface is whitish due to a waxy film (glaucous), but is otherwise similar to the upper surface. The margins are untoothed. The leaves turn red to purple in the fall.

The inflorescence is a dense, flat-topped to shallowly convex, branched, ¾″to 2¾″ in diameter, ⅝″ to 1¼″ tall cluster (cyme) of 35 to 150 flowers at the ends of branches. The flowers are on hairy, 1 ⁄16″ to ¼″ long stalks (pedicels). The flowers appear twice each season, first in mid-May to early June, then again in July to mid-August.

Each flower has four sepals, four petals, four stamens, and a well-developed style. The sepals are fused for most of their length and separated at the tip into four minute teeth. The petals are creamy white, narrowly oblong lance-shaped, and ⅛″ to 3 ⁄16″ long. The stamens are longer than the petals. The flowers are fragrant.

The fruit is a berry-like, 3 ⁄16″ to 5⁄16″ in diameter drupe with one seed. It is green initially, turning white as it matures. It matures in early July (first fruiting) to mid-September (second fruiting). The pedicels persist, remaining on the plant in winter.

3′ to 13′

Creamy white

Gray dogwood (Cornus racemosa) first-year twigs are brown. Bark and second-year twigs are gray and remain gray in winter. The pith is whitish or tan. The leaf stalks are no more than ⅝″ long and are sparsely hairy or hairless. The leaves have no more than four veins per side. The leaf undersides are pale green but not glaucous.

Silky dogwood (Cornus obliqua) first and second-year twigs are greenish-purple, purplish, or reddish-purple. Third-year twigs are gray. The bark is gray. Bark and do not turn red in winter. The pith second-year and older twigs os brown. The leaf stalks are no more than ¾″ long. The leaves have no more than five veins per side. The leaf undersides are pale green but not glaucous. The fruit turns unevenly from white to blue or bluish-purple when ripe. In late summer they are dark blue with white blotches.

Moist. Swamps, marshes, fens, meadows, lake shores, river banks, and ditch banks. Full to partial sun. Shade intolerant.

Two flushes: Mid-May to early June and July to mid-August