Key for Saskatchewan Cuscuta

1a. Flowers all or mostly 4-merous, in globose clusters; corolla (3-) 4 (-5) parted, cylindric-campanulate, the lobes erect; withered corolla capping capsule, but often soon cast off. --- (to 2).

1b. Flowers all or mostly 5-merous; corolla lobes +/- spreading. --- (to 3).

2a. Corolla-lobes obtuse or rounded, much shorter than the tube; calyx-lobes shorter than corolla tube, not reaching sinuses, free nearly to base, very unequal, the outer much overlapping the inner; style equal to or longer than capsule; scales short-toothed along margins and summit. --- C. cephalanthii  (Ver?)

2b. Corolla-lobes acute, subequal to tube, with incurved tips; calyx reaching sinuses of corolla; scales of 2-cleft few-toothed narrow halves. --- C. coryli  (Thr)

3a. Calyx-tube short, the lobes triangular, acute; flowers 2-2.5 mm long, on pedicels longer than flowers. --- C. indecora var. neuropetala  (Ver?)

3b. Calyx-lobes ovate, obtuse.  --- (to 4)

4a. Flowers 1.5-2 mm long, on pedicels subequal to flowers; calyx subequal to and enclosing corolla-tube; corolla-lobe tips inflexed; withered corolla basally attached until shed; calyx angled. --- C. pentagona  (Ver?)

4b. Flowers 2-4 mm long, on pedicels shorter than to subequal to flowers; calyx shorter than and not enclosing corolla tube. --- (to 5)

5a. Corolla-lobes erect; seeds 2-2.8 mm long; scales 2-cleft, long fringed at summit, about half as long as corolla-tube; styles as long as capsules. --- C. megalocarpa  (UC)

5b. Corolla-lobes widely spreading; seeds 1-1.5 mm long; scales oblong, fringed nearly to base, nearly as long as corolla-tube; styles 2/3 as long as capsule. --- C. gronovii  (FC)

This key was proposed by Dr. Mihai Costea (University of Guelph) after reviewing a Cuscuta key published by Dr. V. L. Harms in 2005.

Ver? - unverified in SK
Thr - threatened in SK
UC - uncommon in SK
FC - fairly common in SK