Flower:

Dangling clusters of 1 to 3 stalked flowers arising from leaf axils on lateral branches and branch tips. Flowers are about 1/3 inch long, generally bell-shaped, with 5 short, erect, greenish-white petals that are often tinged with purple around the edges. Extending from inside the tube are 5 creamy-tipped stamens that are about twice as long as the petals.

In the center of the tube is a green style, nearly as long as the stamens; the lower half is densely covered in long, spreading hairs. The calyx cupping the flower is light green, smooth to finely hairy, the 5 sepal lobes rather petal-like, about as long as the stamens and much showier than the actual petals. Sepals are oblong with rounded tips, erect to widely spreading, greenish white and often purplish at the base. Between the calyx and flower stalk is a smooth, green ovary. At the base of the flower stalk are small, egg-shaped bracts that are variously hairy, especially around the edges. Flower stalks are less than ¼ inch long and hairless.

Leaves and stems:

Leaves are 1 to 2½ inches long and nearly as wide, round to diamond-shaped in outline, wedge-shaped to straight across the base, with 3 to 5 lobes that may be further divided into shallow lobes with coarsely toothed edges. Surfaces are smooth to softly hairy and not glandular. Veins are prominent and radiate from the base. Leaf stalks are about ½ inch long and covered in fine, soft hairs.

First year twigs are green and smooth to sparsely covered with prickles; larger spines at the leaf or branch nodes are few or absent altogether. Upper stems become reddish brown with the thin gray bark shedding away along with any prickles. Older, lower stems are gray with scattered, persistent prickles.

Fruit:

Fruit is a smooth, round berry ¼ to 1/3 inch diameter that ripens from green to purplish.

Notes:

The Ribes species consist of both gooseberries and currants. Gooseberries are distinguished by at least some stems having spines or thorny prickles, which currants lack, and clusters of only 1 to 4 flowers, where currants have racemes of 6 or more flowers. Northern Gooseberry (Ribes oxyacanthoides) is most similar and several references state distinguishing it from Swamp Gooseberry can be difficult; we noted several differences from our own observations, though we only sampled a few small populations and recognize there may be natural variations where traits will overlap, and the two may hybridize which makes everything more challenging: R. oxyacanthoides leaves are straight to heart-shaped at the base and one or both surfaces are glandular, where R. hirtellum leaves are straight to wedge-shaped at the base and surfaces lack glands or glandular hairs. The stamens of R. oxyacanthoides flowers are barely longer than the petals, where R. hirtellum stamens are much longer than the petals. R. oxyacanthoides stems are moderately to densely prickly with spines and prickles mostly persisting except in the uppermost stems, where R. hirtellum is more sparsely prickly, with most of prickles and spines shed except towards the base of lower stems.