Helianthus tuberosus L.
The Americas - North, Central and South
This plant is a member of the sunflower family. The flowers of this plant are much smaller than the well known sunflower Helianthus annus. The interesting part of this plant are the tubers.
This is an erect perennial herb which is 1.5 to 3 metres tall with either 1 or several branches. It may be found near houses or creeklines. It is sometimes cultivated for its edible tubers. The plant dies down over Winter and resprouts from the tubers in Spring.
Stems are hairy and woody (easily snapped). Leaves and tubers may be opposite or alternate. Generally upper leaves are opposite. A small leaflet may also be present at the base of each leaf.
Flowers are bright yellow and are present in Summer. Each "flower" is made up of a cluster of tiny flowers (disc florets) in the centre surrounded by yellow "petals" (ray florets).
Fruit is an achene (dry 1 seeded) which is elongated and oval (broader at one end), hairy towards apex.
When trying to remove this plant the tubers should be carefully dug out as even the smallest part of a tuber if left behind will grow.
Use: Tubers are edible - scrape the tubers and either boil or fry.
Other plants easily confused with this plant
Helianthus annuus (Sunflower) is an annual plant of similar proportions often found cultivated in gardens. Helianthus tuberosus has tiny yellow flowers (disc florets) in the centre of each "flower". Helianthus annuus has brownish tiny flowers (disc florets).
Sources & References
"Weeds - an illustrated botanical guide to weeds of Australia" by B. A. Auld and R. W. Medd
"Plantnet FloraOnline" (2005) http://plantnet.rbgsyd.nsw.gov.au/
"Flora of New South Wales" editor Gwen J. Harden, Royal Botanic Gardens Sydney
Prepared by Justin KY Chu, July 2005
Checked by IEWF, November 2006