Cuscuta coryli Engelm.
Family: Convolvulaceae
Hazel Dodder
[Cuscuta corylii Engelm.,  more...]
Cuscuta coryli image

Annual parasitic vine over 50 cm long

Stem: orange or pinkish yellow, climbing on other plants and attaching to them with specialized outgrowths (haustoria) which invade tissue of the host plant to absorb food.

Leaves: alternate, orange or pinkish yellow, very small, scale-like.

Flowers: many, short-stalked, whitish, lustrous, tiny, about 2.5 mm tall, radially symmetric, somewhat cylindric with four, inward pointed petal lobes. The flowers are held on at least 1 mm long, lustrous stalks, and are arranged in dense or lose, short-stalked clusters along the stem.

Sepals: four, but fused for almost half their length, then separating into four pointed lobes which are about half the length of the petals (lobe tips about equal top of petal tube).

Petals: lustrous, four, but fused for about half their length, then separating into four, ascending, fleshy, pimpled, narrowly triangular lobes with pointed and inward flexed or incurved tips.

Stamens: four, attached to inside top of petal tube alternating the petal lobes, with short filaments, and the anthers not extending beyond petal lobes.

Pistil: with one, two-chambered, superior ovary; and two, 0.5 - 1 mm long styles which end in rounded stigmas.

Fruit: small, 2 - 2.5 mm tall, somewhat rounded, often wider than tall, one- or two-seeded, membranous capsules with a thickened area at top. The withered petal tube either remains attached as a cup at the fruit base, or separates and falls away.

Similar species: Cuscuta coryli is most similar to C. cephalanthi and C. polygonorum, but neither of those species have lustrous, pimpled petals and stalked flowers. Further, C. cephalanthi has a much shorter calyx (less than half the petal tube), much shorter and rounded petal lobes, and the withered petal tube remains attached to the top of the capsule like a cap. The main difference separating C. polygonorum is its erect and pointed petal lobes. The remaining species of Cuscuta in the Chicago Region have flowers with five sepals, five petals, and five stamens.

Flowering: July to September

Habitat and ecology: Occasional in wetter areas, including moist prairies.

Occurence in the Chicago region: native

Notes: The Cuscutaceae family has only one genus, Cuscuta. The family has often been treated as a subfamily of the Convolvulaceae family since their flower structures are very similar despite their size differences. However, the two families have distinct chemical properties as well as the obvious differences in life style of non-chlorophyll producing, parasitic vines, versus independent, photosynthesizing, green vines and herbs.

Etymology: Cuscuta is an ancient Latin name for dodder, probably of Arabic origin. Coryli means "of Corylus", a genus in the Betulaceae family, possibly referring to an association between the two.

Author: The Field Museum

From Flora of Indiana (1940) by Charles C. Deam

On plants about lakes and in low woods. The hosts of my specimens are as follows: 1 on Aster, 1 on Campsis, 1 on Corylus, 1 on Prunella, 1 on Sanicula, 2 on Solidago, and 2 on Stachys hyssopifolia.

Fls mostly 4-merous, 2.5 mm, in dense or loose clusters, some or all distinctly pediceled; cal half as long as the cor, its lobes acute; cor cylindric, its lobes narrowly triangular with acute, inflexed tip, about as long as the tube; styles 0.5-1 mm; stigma capitate; withered cor persistent around the base of the fr or calyptrate and pushed off; fr ±globose, 2-2.5 mm, slightly thickened at the top to form a collar around the styles; seeds 1 or 2, 1.5 mm; 2n=30. N.Y. to N.D., s. to Va. and Okla.

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

©The New York Botanical Garden. All rights reserved. Used by permission.

Cuscuta coryli image
Cuscuta coryli image
Cuscuta coryli image
Cuscuta coryli image
Britton, N.L., and A. Brown. 1913.  
Cuscuta coryli image
National Museum of Natural History Image Collection  
Cuscuta coryli image
Royal Botanic Garden Edinburgh  
Cuscuta coryli image
Royal Botanic Garden Edinburgh