- Pest Type: Weed
- Crops Affected: Wheat, Cotton, Potatoes, Soybeans, Corn
- Scientific Name: Helianthus tuberosus
- Pest Order: Asteraceae
A tall (1-3 m) rhizomatous and tuberous perennial. It is sometimes cultivated for its edible tubers, but once established is aggressive and difficult to control.
Reproduction is mainly by tubers but also by seed. Tubers produced in the previous year begin to sprout in late spring. Rhizome production begins just before flowering. Tuber production begins in midsummer, and reaches its peak in late summer or early autumn. Tubers are short-lived; they do not survive form more than one or two seasons.
Cotyledons are oval, twice as long as wide, and united at the base, forming a short tube. The first leaves are opposite and elliptic.
Leaf blades are dull green on the upper surface, pale on the underside, and covered with short stiff hairs.
Stems are coarse and stout with rough hairs. Leaves are simple, ovate or almost heart-shaped to oblong-lanceolate, tapering to a narrow tip, 10-25 cm long by 4-12 cm wide. Leaf blades are thick, rough on the upper surface, with short grayish hairs on the lower surface. Margins are coarsely toothed, and petioles are winged. Lower leaves are opposite, but leaves on the upper half of the stem are alternate.
One to five flower heads are produced at the terminal end of stems from August through October. Heads are about 5 cm in diameter with 10-20 yellow ray flowers (2-4 cm long) surrounding the darker yellow disk flowers. Each seed is enclosed in the fruit (achene), which is 4-8mm long, oblong to wedge-shaped, and flattened.
Above ground parts die back after frost and do not persist. The plant overwinters as a tuber.
Jerusalem artichoke is sometimes cultivated for the edible tubers. It is a weed of nurseries, landscapes, orchards, and reduced-tillage agronomic crops, as well as roadsides and waste places. It is often found on rich, moist soil. Foliage and tubers are readily eaten by livestock and deer.
This weed continues to spread in the eastern half of the United States and is increasing in many Midwestern states and states adjacent to Canada. It is also found near the Pacific coast.
Common sunflower is similar, but is an annual with a fibrous root system and does not product tubers. Maximilian sunflower is also similar, but has leaves more than 3 times longer than broad, and some of the middle leaves fold lengthwise.