How to identify Japanese knotweed (Reynoutria japonica)
Japanese knotweed, also known as Fleeceflower, Elephant ears
Japanese knotweed displays heart-shaped green leaves that can reach up to 6 inches (15 cm) in length, with a pointed tip and a slightly rippled edge. The stems are hollow and bamboo-like, typically growing 6 to 9 feet (about 2 to 3 meters) tall. During late summer, japanese knotweed produces small, creamy white flowers in branched clusters. The plant is highly robust, with a deep and vigorous rhizome system that can push through hard surfaces.
Lifespan: Perennial
Plant Type: Herb
Leaf Type: Deciduous
Heart-shaped green leaves with rippled edges, up to 6 inches (15 cm) long.
Hollow bamboo-like stems, 6 to 9 feet (2 to 3 meters) tall.
Small creamy white flowers in branched clusters during late summer.
Distinct triangular-shaped dark brown to black fruit with winged achenes.
Large, hollow, jointed stem with mottled pattern resembling bamboo, reaching up to 10 feet (3 meters).
The leaves of japanese knotweed are broadly oval to triangular in shape, measuring 3 to 7 inches (7.5 to 17.8 cm) long and 2 to 4 inches (5 to 10 cm) wide. They are dark green on the upper surface and light green below, featuring reddish veins. The leaves have sharply pointed tips, entire margins, and truncated bases. They alternate along the stem, attached by sheath-like structures called ochreae, with new growth being red.
The flowers of japanese knotweed are small, creamy-white, and feature five tepals arranged in 3-6 inch (7.5-15 cm) long erect panicles emerging from the leaf axils from late summer to fall. These flowers are dioecious, with male flowers being more erect, while female flowers tend to droop. The distinct appearance and arrangement make them easily identifiable to plant enthusiasts.
The stem of japanese knotweed is characterized by its green to reddish-brown color, and it is large, hollow, and slightly ridged lengthwise. The stem is jointed and often displays a mottled pattern, resembling bamboo. These stems can remain standing after the plant dies back to the ground. Older stems become woody near the base. Typically, the stems can reach lengths of up to 10 feet (3 meters).
The fruit of japanese knotweed is a small, winged achene that carries a distinct triangular shape. Each fruit presents a shiny surface and is dark brown to black in color, providing a striking visual against the foliage. Spanning only a few millimeters in size, the contained seeds echo the fruit's triangular geometry. This achene's texture, combined with its color and form, makes it a unique feature that assists in the identification of japanese knotweed. The fruit's diminutive stature and winged nature facilitate its dispersal by wind, aiding in the propagation of japanese knotweed.
Scan QR code to download
Gardenia jasminoides is an evergreen shrub with unique, glossy evergreen leaves and stunning flowers. The sophisticated, matte white flowers are often used in bouquets. The exceptional beauty of this ornamental plant has made it a popular and highly appreciated plant amongst gardeners and horticulturalists.
The golden pothos (Epipremnum aureum) is a popular houseplant that is commonly seen in Australia, Asia, and the West Indies. It goes by many nicknames, including "devil's ivy", because it is so hard to kill and can even grow in low light conditions. Golden pothos has poisonous sap, so it should be kept away from pets and children.
Solanum lycopersicum is an annual or perennial herbaceous vine native to Central and South America that produces a large, juicy, edible fruit known as tomato. Today there are over 10000 cultivated varieties. Although tomato is the world’s most popular vegetable, botanically it is a fruit.
The pepper are commonly used for cooking in places such as the Southern U.S. and Central America. Most are moderately spicy, though because there are so many variants, the spice level can vary dramatically. Cayenne powder is also a popular seasoning product made from pepper plants.
The swiss cheese plant (Monstera deliciosa) produces bright, glossy leaves and makes a popular houseplant. It is originally native to tropical forest regions in Central America. The nickname swiss cheese plant refers to the small holes that develop in the plant's leaves. The long fruits resemble corncobs and smell sweet and fragrant when ripe.
The bigleaf hydrangea is a deciduous shrub native to Japan, and is known for its lush, oval, colorful inflorescence. The two types of Hydrangea macrophylla are mopheads - with large, ball-shaped, sterile flower clusters, and lace capes - with small round fertile flowers in the center, and sterile flowers on the outer side of each inflorescence. Depending on soil pH, blooms can change color from pink to blue.
Identify a Plant Online
Scientific Classification of Japanese knotweed
