The grapevine is a perennial, deciduous plant belonging to the genus Vitis, cultivated globally for its fruit. As a woody vine, it possesses a distinct physical structure that allows it to climb and sprawl across supports. Its appearance changes throughout the growing season, moving from a thick, twisting woody base in winter to a large, leafy canopy that bears fruit in the summer.
The Woody Structure and Growth Habit
A grapevine is classified as a liana, a long-stemmed, woody vine that roots in the soil and climbs high to reach sunlight. The main, permanent above-ground part is the trunk, which provides structural support and transports water and nutrients. On a mature plant, the trunk often develops a thick, twisting, and gnarled appearance.
The bark on older wood is typically brown or gray and tends to shred or peel easily due to the formation of a cork layer beneath the surface. Younger, one-year-old woody shoots are called canes, which are lighter in color and smoother, forming in the autumn after dropping their leaves. Canes are partitioned into nodes, the thickened sections where new growth emerges, and internodes, the sections between them.
Identifying Foliage and Appendages
Grapevine leaves are a distinct identifying feature, with most varieties having large, green leaves that are often palmate, resembling a hand with several lobes. The edges of the leaf blades are typically serrated or tooth-edged. The upper surface is relatively smooth, while the underside may be lighter in color or covered with fine hairs, depending on the specific cultivar.
The tendril is the primary climbing tool of the grapevine. These slender, thread-like structures emerge opposite a leaf node on the new shoots. Tendrils are thigmotropic, meaning they are sensitive to touch, and coil tightly around any object they contact to provide secure anchorage.
Fruit and Flower Characteristics
The reproductive cycle begins with the development of small, inconspicuous, greenish flowers. These flowers are grouped together in an inflorescence, or cluster, on the shoot opposite a leaf. The flower structure features five fused petals forming a cap, or calyptra, which detaches as the flower blooms, exposing the internal reproductive parts.
Following successful pollination, the flower’s ovary develops into the fruit, botanically a berry known as a grape. Grapes grow in tight or loose clusters, with each berry attached to the main cluster stem by a small pedicel. Fruit color varies significantly, ranging from pale green and yellow to deep red, purple, and nearly black. Many varieties display a whitish, powdery coating on the skin called a bloom, and the berries contain a juicy pulp and typically house seeds.