Practical ecological knowledge for the temperate reader.

Oxycoccus macrocarpus - American Cranberry

Family: Ericaceae (Heath family)

Other Names: Large cranberry.

" Vaccinium macrocarpon is an evergreen Shrub growing to 0.2 m (0ft 8in) by 2 m (6ft) at a medium rate. It is hardy to zone (UK) 2. It is in leaf 12-Jan It is in flower from Jun to August, and the seeds ripen from Aug to October. The flowers are hermaphrodite (have both male and female organs) and are pollinated by Insects, self.The plant is self-fertile. Suitable for: light (sandy) and medium (loamy) soils, prefers well-drained soil and can grow in nutritionally poor soil. Suitable pH: acid soils and can grow in very acid soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist or wet soil." [PFAF]


"General: Creeping shrub; stems slender, 10-40 cm long, sometimes finely hairy when young." [IFBC-E-flora]
"Leaves: Evergreen, alternate, leathery, narrowly elliptic-oblong to oblong, 7-15 mm long, glossy above, very pale beneath, margins slightly rolled under; stalks about 1 mm long." [IFBC-E-flora]
"Flowers: Lateral on leafy branches, single in the axils of reduced leaves at base of current shoots; flower stalks 2-4 cm long, glabrous or hairy, curved at flowering, with 2 leaf-like bracts, 3-10 mm long, well above the midlength of the stalk; corollas deep pink, of 4 distinct narrow petals, 6-10 mm long, spreading or curved back; calyx lobes 4; stamens 8, filaments broad, sparsely hairy on margins, about 1/3 the length of the anther sacs; anthers unawned, with terminal tubes." [IFBC-E-flora]
"Fruits: Berries, globe-shaped, 10-20 mm wide, deep red." [IFBC-E-flora]
"Notes: Although sometimes considered part of the genus Vaccinium, Oxycoccus is treated separately here (as in many other floras). The flowers of Oxycoccus are 4-merous and the corollas are deeply parted, with only the base being joined. In contrast, the corollas of Vaccinium are united and generally only toothed or undulating at the summit. The differences in the flowers and growth habit seem to justify the separation." [IFBC-E-flora]

Habitat / Range
"Moist to wet bogs and ditches in the lowland zone; rare escape from cultivation in SW BC (lower Fraser R. valley); introduced from NE North America." [IFBC-E-flora]

Origin Status: Exotic " [E-flora]

This wild fruit is native in open bogs and marshes from Newfoundland to western Ontario, south to Virginia and Arkansas. Some of the berries that we see in the markets have been gathered from the wild plants especially in Michigan and Wisconsin. The majority of the market berries have been obtained by cultivation especially in the Cape Cod district and from south Jersey and Wisconsin. [EWP]

Edible Uses

Medicinal Uses

CRANBERRY (Vaccinium macrocarpum Aiton)
Synonym — Oxycoccus macrocarpos (Aiton) Pers." [HMH Duke]
Activities (Cranberry) — "Antiaggregant (1; JNU); Antibacterial (1; FNF; SKY); Antioxidant (1; JNU); Antiscorbutic (1; CEB); Antiseptic (1; FAD; PED); Bitter (PED); Diuretic (f; CEB; PED); Hypoglycemic (1; LEL); Laxative (f; CEB); Urinary Antiseptic (1; FAD)." [HMH Duke]
Select Indications (Cranberry) — Bacteria (1; FNF; SKY); Cancer (f; CEB; JLH); Cancer, breast (f; JLH); Cancer, cheek (f; JLH); Cancer, skin (f; JLH);; Erysipelas (f; CEB; FEL); Nephrosis (2; PED; SKY); Pleurisy (f; CEB; DEM); UTI (2; FAD; JNU); Water Retention (f; CEB; PED); [HMH Duke]
"Dosages (Cranberry) — 3 fluid oz (90 ml) fruit juice/day (APA preventative); 12–32 fluid oz fruit juice/day (APA curative); 1 oz cranberry juice cocktail = 2 capsules (APA); 5–20 oz/day; 800 mg capsules; 2–4 (505 mg) capsules 3 ×/day; 2–3 (505 mg) capsules StX with meals (APA); 1/2 cup fresh fruit (PED); 1 tbsp dry fruit (PED); 15 g dry fruit:20 ml alcohol/130 ml water (PED)." [HMH Duke]
"Contraindications, Interactions, and Side Effects (Cranberry) — Strangely (AHP) omitted this from their Botanical Safety Handbook, but I suppose they would call it Class 1. The Commission E and herbal PDR apparently also ignored this excellent food farmaceutical too (KOM; PHR). Ingestion of ridiculous amounts (3–4 liters a day) may cause diarrhea and other GI disorders (LRNP, Aug. 1987). Lininger et al. (1998) say it is safe for use during pregnancy and lactation. Should not be used as an antibiotic substitute during acute UTI (SKY)." [HMH Duke]
"Extracts (Cranberry) — Anthocyanins and polyphenols in berries of several Ribes, Rubus, and Vaccinium spp have in vitro antiradical activity on chemically generated superoxide radicals. The extracts also inhibitory xanthine oxidase. All crude extracts were highly active toward chemically generated superoxide radicals. Ribes nigrum extracts exhibited most activity, being the richest in both anthocyanins and polyphenols. But Ribes rubrum extracts seem to contain more active substances (X1332092)." [HMH Duke]


"Requires a moist or semi-boggy lime free soil, preferring one that is rich in peat or a light loamy soil with added leaf-mould[11, 200]. Prefers a very acid soil with a pH in the range of 4 to 4.5, plants soon become chlorotic when lime is present[200]. Plants grow best in a poor soil, richer soils result in extra foliage production at the expense of fruit[200]. Succeeds in full sun or light shade though it fruits better in a sunny position[200]. Requires shelter from strong winds[200]. A very dwarf shrub producing long slender creeping stems that root into the soil. Upright stems grow from the axillary buds in the second year and these upright stems flower and fruit the following year[200]. Widely cultivated for its edible fruit in N. America, there are many named varieties[11, 183, 200]. Cultivated plants are usually grown in artificial bogs that are often flooded in the winter[200]. Plants can self-fertilize but cross-fertilization by insects results in higher yields[200]. Cultivated plants take about 5 years to come into full bearing but will then crop well for 60 - 100 years[200]. Dislikes root disturbance, plants are best grown in pots until being planted out in their permanent positions[200]. Plants in this genus are notably resistant to honey fungus[200]." [PFAF]

Thousands of acres are under cultivation for this purpose. Low boggy land with a peat bottom is generally selected, and in winter the areas are flooded. Under cultivation the berries are usually larger, and the plants more productive. [EWP]

Groundcover: "Plants can be grown as a ground cover when planted about 1 metre apart each way[208PFAF]. Plants rapidly form a dense carpet when they are thriving [208]." [PFAF]

"Seed - sow late winter in a greenhouse in a lime-free potting mix and only just cover the seed[78]. Stored seed might require a period of up to 3 months cold stratification[113]. Another report says that it is best to sow the seed in a greenhouse as soon as it is ripe[200]. Once they are about 5cm tall, prick the seedlings out into individual pots and grow them on in a lightly shaded position in the greenhouse for at least their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. Cuttings in April of shoots 15cm long, in a sandy mix in a frame covered in plastic to keep them moist[200]. Cuttings of half-ripe wood, 5 - 8cm with a heel, August in a frame[78]. Slow and difficult. Layering in late summer or early autumn[78]. Another report says that spring is the best time to layer[200]. Takes 18 months[78]. Division of suckers in spring or early autumn[113]." [PFAF]

Oxycoccus Sp. - Cranberry

Family: Ericaceae - Heath

Local Species;

  1. Oxycoccus macrocarpus - American cranberry [E-flora]
  2. Oxycoccus oxycoccos - bog cranberry [E-flora]

Bog Cranberries (Oxycoccus spp.; also commonly included as a subgroup in the genus Vaccinium) including; O. Macrocarpus, large or American bog cranberry; O. microcarpus, small-fruited bog cranberry; O. ovalifolius, ovalleaved bog cranberry; and O. quadripetalus, four-petalled bog cranberry. The taxonomy of these species is very complex and confusing. The last three are often included in a complex known as "Vaccinium oxycoccus." Indigenous People seldom distinguished among the bog cranberries in any formal way. The berries were prepared and eaten in similar ways, and hence the Oxycoccus species are treated here together. [????]


  1., Accessed April 12, 2015
  2., Accessed April 11, 2015

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