''Swida (formally Cornus) rugosa'', commonly called roundleaf dogwood or round-leaved dogwood, is a

deciduous In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed Leaf, leaves, usually in the autumn; to the shedding of petals, aft ...

tree native to northern parts of the eastern and central United States and southern parts of central and eastern Canada.

Description

''Swida rugosa'' is a

shrub A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple ...

or small

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only ...

, tall, with yellowish-green twigs that may have red or purple blotches.

Pith Pith, or medulla, is a tissue in the stems of vascular plants. Pith is composed of soft, spongy parenchyma cells, which in some cases can store starch. In eudicotyledons, pith is located in the center of the stem. In monocotyledons, it ex ...

is white. Leaves are oppositely arranged, round orbicularly shaped with an acuminate tip, have an entire margin, and are woolly to hairless below. Leaves have 6-8 pairs of lateral veins and 7–15 cm long.

Leaf scar A leaf scar is the mark left by a leaf after it falls off the twig. It marks the site where the petiole attached to the stem. A leaf scar is typically found below a branch, as branches come from axillary buds located above leaf scars. Formation ...

s are broadly U-shaped with 3 bundle scars. White flowers appear in early summer arranged on flat topped cymes. The flowers themselves are pedunculate with 4

calyx CALYX, Inc. is a non-profit publisher of art and literature by women founded in 1976 based in Corvallis, Oregon. CALYX publishes both '' CALYX, A Journal of Art and Literature by Women'' twice a year and CALYX Books, which publishes one to three ...

lobes and 4 petals. The cymes are wide and contain 20–50 flowers. Fruits are blue to greenish white

drupe In botany, a drupe (or stone fruit) is a type of fruit in which an outer fleshy part (exocarp, or skin, and mesocarp, or flesh) surrounds a single shell (the ''pip'' (UK), ''pit'' (US), ''stone'', or ''pyrena'') of hardened endocarp with a seed ...

that matures in October. Roundleaf dogwood prefers well drained to normal moisture soil and, like most dogwoods, is shade tolerant.

Ecology

Roundleaf dogwood is a host species for the

spring azure ''Celastrina ladon'', the spring azure or echo blue, is a butterfly of the family Lycaenidae. It is found in North America from Alaska and Canada south of the tundra, through most of the United States except the Texas coast, southern plain and p ...

and gossamer wings. Fruits are eaten by

ruffed grouse The ruffed grouse (''Bonasa umbellus'') is a medium-sized grouse occurring in forests from the Appalachian Mountains across Canada to Alaska. It is the most widely distributed game bird in North America. It is non-migratory. It is the only spe ...

and

sharp-tailed grouse The sharp-tailed grouse (''Tympanuchus phasianellus''), also known as the sharptail or fire grouse, is a medium-sized prairie grouse. One of three species in the genus ''Tympanuchus'', the sharp-tailed grouse is found throughout Alaska, much of N ...

. Twigs are consumed by

white tailed deer The white-tailed deer (''Odocoileus virginianus''), also known Common name, commonly as the whitetail and the Virginia deer, is a medium-sized species of deer native to North America, North, Central America, Central and South America. It is the ...

Eastern cottontail The eastern cottontail (''Sylvilagus floridanus'') is a New World cottontail rabbit, a member of the family Leporidae. It is the most common rabbit species in North America. Distribution The eastern cottontail can be found in meadows and shrub ...

, and

mice A mouse (: mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...

Conservation

Roundleaf dogwood is listed as endangered in

Maryland Maryland ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. It borders the states of Virginia to its south, West Virginia to its west, Pennsylvania to its north, and Delaware to its east ...

and is a species of special concern in

Rhode Island Rhode Island ( ) is a state in the New England region of the Northeastern United States. It borders Connecticut to its west; Massachusetts to its north and east; and the Atlantic Ocean to its south via Rhode Island Sound and Block Is ...

References

External links

* {{Taxonbar, from=Q15605468

rugosa The Rugosa or rugose corals are an extinct Class (biology), class of solitary and Colony (biology), colonial corals that were abundant in Middle Ordovician to Late Permian seas. Solitary rugosans (e.g., ''Caninia (genus), Caninia'', ''Lopho ...