Plant Talk: Ribes; the Currant and Gooseberry Family – Grossulariaceae

By Patsy Cotterill

The genus Ribes

The currants and gooseberries belong in the genus Ribes, the single genus that constitutes the family Grossulariaceae. It is primarily a Northern Hemisphere group, with some 150-200 species, of which we have 13 in Alberta. Of these, seven are common locally in the Parkland, and all prefer habitats with an adequate supply of water, from moist woodlands and meadows to the shores of wetlands and creeks. Ribes species are ecologically important, given their abundance and widespread distribution; their foliage is food for the larvae of butterflies and moths, and their fruits are eaten by birds and mammals. As early-flowering species, their nectar is a food source for spring-emerging insects, including bees. They are susceptible to a number of fungal rusts; some species are alternate hosts for white pine blister rust (Cronartium ribicola, a non-native fungus) which infects five-needled pine trees. This is the case with flowering currant, Ribes sanguineum, which is native to B.C. and the western U.S., and is also widely cultivated as an ornamental in Europe and Australasia. At one time it was subject to eradication efforts in the U.S. but this has since stopped, both the currant and the tree having developed resistance to the rust. This is fortunate, as flowering currant is important for our wildlife. 

Gooseberries and currants are of course cultivated for their fruits: cultivated gooseberries are derived from Ribes hirtellum in North America and R. uva-crispa in Europe, while horticultural currants have been developed from European and Asian species. 

The characteristics of Ribes

As a monogeneric family, the characters of the genus are also those of the family. Ribes are deciduous shrubs growing erect or with a somewhat sprawling or climbing habit, and are often rather untidy in appearance. Their stems may or may not be prickly with spines and smaller, more numerous bristles. The alternate leaves are palmately lobed, often with five main veins extending to the lobes, and grouped into small clusters on the branches. The flowers are small but usually numerous, often in stalked inflorescences called racemes. A small bract subtends each flower stalk which may or may not be jointed. If a joint is present, the fruit falls with only a partial stalk attached to it. A cup- or tube-like extension of the receptacle (a hypanthium) surrounds and is attached to the ovary and prolonged beyond it to produce saucer-shaped or tubular flowers. The five sepals are joined into a tube below, with free lobes; they are invariably larger than the petals, and coloured, not green. A nectary disc covers the top of the ovary but is conspicuous only in species with saucer-shaped flowers. The five stamens are attached to its rim. The relative length of the stamens to the petals is a useful identifying character. The two styles topped with stigmas are joined for various lengths depending on the species. The ovary is round and inferior (i.e., below the flower parts) and will develop into a many-seeded, juicy, berry which may be smooth and hairless or variously glandular-bristly. 

All our gooseberries and currants flower in the spring and are setting fruit by mid-summer. The frequent occurrence of prickles in the genus suggests that they may present a useful deterrent to large herbivores. The function of the glandular hairs, stalked or otherwise, on the floral organs is not so clear; possibly they serve to confound small insects. Some species also bear stalkless, clear or yellow glands on their leaves which exude a resin that produces the characteristic “currant” odour.

Our local species are mostly distinguishable by eye, taking into account distinctive combinations of leaf, flower and inflorescence characters. The first distinction to be made in separating the species is whether the plant has spines or bristles along the stem and branches (gooseberries) or smooth stems lacking them (currants). Our common Parkland species with spines are Ribes lacustre, R. oxyacanthoides and R. hirtellum, while those without are R. americanum, R. hudsonianum, R. glandulosum and R. triste. 

1. Bristly black currant (Ribes lacustre), past flowering, showing pendant racemes on a horizontal branch, dense prickles on the stems and glossy, five-lobed leaves. E.C. Manning Provincial Park, B.C. 2011-07-20. Photo: P. Cotterill.

2. Bristly black currant (Ribes lacustre) showing saucer-shaped flower structure, with broad, creamy sepals, minute petals and stamens inserted on the nectary disk. The ovaries are bristly with red, gland-tipped hairs. (The species blooms earlier in the lowlands than in the mountains.) Sandhills Trail, Elk Island National Park. 2019-05-25. Photo: P. Kyle.

   
   

Bristly black currant (Ribes lacustre) is an erect, medium-sized shrub that can be readily distinguished from the other two species with spines by its saucer-shaped flowers that are cream-coloured with reddish coloration. It is also notably densely spiny and prickly, with large spines at the leaf nodes, making it unpleasant to touch and its common name something of an anomaly. The three- or five-lobed leaves span 1-7cm, are straight or slightly heart-shaped at the base, and so glossy on the upper surface that even when the plant is not in flower it can be singled out and identified by its shining foliage. The sepals are about 2 mm long, longer than the petals at 1.3 mm, and the stamens are the same length as the sepals. The ovary is glandular-bristly and develops into a black bristly berry at maturity. 

1. Canada gooseberry (Ribes oxyacanthoides) showing leaves and an open tubular flower in which the sepal lobes are reflexed and the stamens are approximately the same length as the petals. Sandhills Trail, Elk Island National Park. 2019-05-25. Photo: P. Kyle.

2. Canada gooseberry (Ribes oxyacanthoides) showing developing fruits. The remnants of flower parts atop the ovary indicates that the ovary is inferior. Indian Graves Provincial Recreation Area, Kananaskis Country. 2022-06-28. Photo: P. Cotterill.

Canada or northern gooseberry (Ribes oxyacanthoides) and swamp gooseberry (R. hirtellum), the other two of our species with prickles, are superficially similar and more difficult to tell apart. Both have relatively small leaves (1-4 cm), which are roundish in outline, and bear small clusters of white, tubular flowers which will produce hairless, green, pinkish or blackish berries. In Canada gooseberry the sepals (4.5-5 mm long) are longer than the petals which are matched by the stamens in length (sepals > petals = stamens), whereas in swamp gooseberry the stamens are equal in length to the sepals which are double the length of the petals (sepals = stamens > petals).

1. Swamp gooseberry (Ribes hirtellum) in flower, showing the habit of the plant. Nisku Prairie. 2022-06-04. Photo: P. Cotterill.

2. Swamp gooseberry (Ribes hirtellum) showing tubular flowers in which the stamens are clearly longer than the petals, which are short structures between the white sepal lobes. Note also the clustered leaves on short shoots (another characteristic of Ribes species) and the red-brown colour of the stem. Nisku Prairie. 2022-06—04. Photo: P. Cotterill.

There are other differences. Canada gooseberry is much the pricklier plant with a bristly stem and nodal spines, whereas swamp gooseberry has few spines on the older, brownish stems, prickles being confined to the new canes. Ribes oxyacanthoides is more of a forest species, often sprawling or scrambling over other woody vegetation, whereas R. hirtellum is a bushier plant found in wet meadows and open woods. There are considerable populations of swamp gooseberry in the grasslands of Elk Island National Park and Nisku Prairie. 

Although I have not seen much evidence of prolific fruit production locally, swamp currant is esteemed for its fruit production and, given its bushy habit, it would be a good plant to grow in the garden, either as a hedge or a component of a shrubbery, making a nice addition to spring-flowering shrubs. Perhaps ENPS should learn how to grow it from cuttings?

1. Swamp currant (Ribes triste) showing a raceme of saucer-shaped flowers and unfolding leaves, growing in a forest area of a home garden, Edmonton. 2011-05-18. Photo: P. Cotterill.

2. Close up of flowers of swamp currant (Ribes triste) showing broad, pink sepals, small deep-ink petals and stamens inserted around the rim of the nectary disk, with two styles in the centre. Sandhills Trail, Elk Island National Park. 2019-05-25. Photo: P. Kyle.

3. Smooth (glandless) red fruits of swamp currant (Ribes triste) in forest, Lesser Slave Lake Provincial Park. 2011-08-05. Photo: P. Cotterill.

Of the remaining species, which are all spineless and therefore are called currants, swamp red currant (Ribes triste) is the earliest to flower. It has the most spindly habit, consisting of only one or two stems that can easily get missed amid other woodland vegetation. It is usually the long, drooping, glandular racemes of pink, saucer-shaped flowers, which appear before the leaves are fully unfolded, that draw attention to it. The broad sepals are about 2 mm long, twice the size of the petals between them. The faded flowers remain in place above the developing ovary for a considerable period of time, often giving the false impression of a long flowering period. The leaves are large, to 8.5 cm, broadly triangular, with pointed and coarsely toothed lobes, as well as being somewhat veiny and crumpled-looking. The berries are smooth, red, sour, and rarely produced in large quantities.

1. Skunk currant (Ribes glandulosum) showing cup-shaped flowers with pink-purple stamens and ovaries with glandular hairs. Sandhills Trail, Elk Island National Park. 2009-05-30. Photo: P. Cotterill.

2. Skunk currant (Ribes glandulosum) showing developing glandular-bristly ovaries with remains of flower parts. Sandhills Trail, Elk Island National Park. 2015-05-30. Photo: P. Kyle.

Skunk currant (Ribes glandulosum) is a low, spreading shrub of wet spots in moist woods or stream sides. Its leaves are round in outline, 3-8 cm, five- to seven-lobed, somewhat heart-shaped at the base and rather shiny above. The deeply saucer-shaped flowers are grouped in short racemes and can look particularly attractive with their creamy-white sepals, tiny pink petals and pink stamens that fade to purple. The ripe fruit is dark red and glandular bristly. The plant derives its common name from the fact that crushed leaves have an odour of skunk. It would, however, make a good shrub for the water garden. 

1. American black currant (Ribes americanum) in flower, and showing habit of growth. Wagner Natural Area. 2022-05-28. Photo: P. Cotterill.

2. Close up of racemes of American black currant (Ribes americanum). Wagner Natural Area. 2022-05-28. Photo: P. Cotterill.

3. Close up of flowers of American black currant (Ribes americanum) showing tubular flowers with large, outspreading septal, forward-directed, blunt-edge petals, stamens, and two stigmas atop the styles. Whitemud Park, Edmonton. 2010-05-19. Photo: P. Cotterill.

4. Developing fruits of American black currant (Ribes americanum) in woods at Birch Cove, Alberta. 2009-08-03. Photo: P. Cotterill.

American black currant (Ribes americanum) is one of the taller, bushier shrubs which is also showy, producing multiple drooping racemes of many yellow, tubular flowers. The flowers are relatively large, with sepals 4.5-5 mm and petals 2.5-3 mm. The leaves are 2-7 cm, three- and five-lobed and straight or slightly heart-shaped at the base. They are dotted beneath with tiny, yellow, stalkless glands that produce the characteristic pungent “currant” smell when the leaves are crushed. The fruits are black and smooth, lacking glands. This species definitely prefers the wetter spots in woods and treed fens, but could make a showy garden shrub if moisture is adequate. 

1. Northern black currant (Ribes hudsonianum) in flower along the Marl Pond Trail, Wagner Natural Area. 2010-05-24. Photo: P. Cotterill.

2. Northern black currant (Ribes hudsonianum) in fruit, in wet forest, Zeiner Campground, Pigeon Lake Provincial Park. 009-07-19. Photo: P. Cotterill.

Hudson Bay currant (Ribes hudsonianum) is a less robust shrub than American black currant and seems to have a somewhat greater preference for forested peatland habitats, although the two species co-occur, for example, in Wagner Natural Area. The flowers appear relatively small, possibly because of their cup shape, and have bright white sepals about 4 mm long and petals 1.5-2 mm long.  The leaves are 2-12 cm and predominantly three-lobed with a rather short terminal lobe; they are also dotted with stalkless glands beneath and have the same characteristic smell as American black currant. However, they also have these yellow glands on leaf stalks and ovaries, so the “currant” odour is stronger, giving rise to another common name for this species of stinking currant. The berry is black at maturity and may have a few stalkless glands or none at all. Two varieties of this species are now recognized as occurring in Alberta: var. hudsonianum, which is conspicuously hairy but whose fruits lack glands, and var. petiolare, which is sparsely hairy and whose fruits bear sparse, stalkless glands. Var. hudsonianum has a more northern distribution and var. petiolare a western one.  There is thus a good possibility of overlap of the varieties in the Edmonton area, a nice little project to investigate for those botanists addicted to detail!

Mention should also be made of golden currant (Ribes aureum), which only grows naturally along the river banks and rocky slopes of southern Alberta and Saskatchewan, but is cultivated as an attractive shrub for its copious yellow, tubular flowers which exude a pleasant scent, and for its fruit.

Distribution of Ribes in Alberta and Canada

As might be expected given their forest habitats, all species (except golden currant) are more common in the northern part of the province, although Canada gooseberry is common throughout. American red currant is absent from the north and west of the province and swamp gooseberry is particularly common in the central part of Alberta. Regarding their range in Canada, all species are widespread, although American red currant and swamp currant are absent from B.C. 

My impression – not based on solid scientific monitoring – is that population numbers of several species have declined in recent years, possibly due to drought. Skunk currant seems to have vanished from Patricia Ravine in Edmonton, for example, and swamp red currant remains occasional. American red currant, however, seems to have increased at the expense of other Ribes species.

All seven species occur in Wagner Natural Area, its Marl Pond Trail providing good opportunities to test identification skills, and along trails in Elk Island National Park. 

References

canadensys vascan https://www.bing.com/search?FORM=ARPSEC&PC=ARPL&PTAG=30250&q=canadensys%20vascan

Flora North America. Vol. 8. Ribes. http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=128544

Kershaw, Linda & Lorna Allen. 2025. Vascular Flora of Alberta: An Illustrated Guide. Second edition. Self-published. Kindle Direct Publishing.

Wikipedia: Ribes sanguineum. https://en.wikipedia.org/wiki/Ribes_sanguineum

Moss, E.H. 1982. Flora of Alberta. 2d ed. Rev. by J.G. Packer. Toronto, University of Toronto Press.