The five taxa occurring in Norden may be attributed to three different genera: Chamaepericlymenum Hill (for C. suecica), Swida Opiz (for C. alba, C. sanguinea, C. sericea) and Cornus s.str. (C. mas). The family Cornaceae has been subject to a number of comprehensive modern studies using molecular and cladistic methods (Murrell 1993, Xiang et al. 1996, Fan & Xiang 2001, Xiang et al. 2002). These studies show clearly that while the three genera mentioned are all monophyletic entities, this is valid for Cornus s.lat. as well. Both taxonomic views are consequently defensible from a phylogenetic stand-point; no taxonomic recommendation is made by the authors mentioned. A subdivision of the genus Cornus has been adopted by Lid & Elven (2005); Flora Nordica follows the traditional Nordic view of a Cornus s.lat., which seems more practical for a group with such a limited number of species (c. 60 worldwide, see Eyde 1987).
Cornus L. Illustration (C. alba and C. sericea)
Linnaeus, Sp. pl.: 117 (1753)
Shrubs (rarely small tress) or perennial herbs; buds without scales but with appressed brownish hairs (vegetative buds small, narrow, acute, floral ones larger and thicker). Leaves opposite, undivided, rather stiff with prominent arcuate side veins; margin entire.
terminal or axillary, corymb- or umbel-like. Petals
campanulate or urceolate with 4 rather unconspicuous teeth. Stamens
4, inserted between the petals on an epigynous disc; anthers dorsifixed. Ovary
inferior, fused with the calyx tube, usually bilocular, with 2 carpels. Fruit
a drupe, containing a pyrene with 2 seeds.
||Inflorescence subtended by petaloid bracts; fruits red; shrub or herb
||Small, non-petaloid, adnate bracts at the base of the inflorescence; fruits dark blue to white; shrub
||Bracts white, petals dark; herb with subterranean runners
||Bracts and petals yellowish; shrub
||Petals 3.5-c. 7 mm; leaves usually with 3-5 pairs of side-veins; indumentum on lowerside of leaves dominated by simple, ± curved hairs (medifixed hairs few); fruits dark blue to black
||Petals up to c. 4 mm; leaves with up to 7 pairs of side-veins; indumentum on lowerside of leaves dominated by medifixed hairs (simple hairs few or lacking); fruits whitish to light blue
||With suckers and often prostrate rooting branches; leaves acuminate with long tapering apex; calyx teeth up to c. 5 mm; pyrene subglobose, rounded at base
||Without suckers or rooting branches; leaves acute to rather abruptly acuminate; calyx teeth not longer than 3 mm; pyrene ellipsoid, cuneate at base
1. Cornus suecica L. Map
Linnaeus, Sp. pl. 118 (1753). - Chamaepericlymenum suecicum (L.) Aschers. & Graebn. (1899). - Type: Linnaean Herbarium 151.12 (LINN), lectotype, sel. by Jonsell & Jarvis, Nordic J. Bot. 22: 83 (2002).
D Hønsebær. F ruohokanukka. Fa royuber. I skollaber. N kvitkornell. S hönsbär.
Hemicryptophyte. Perennial herb with extensively creeping, richly branched, scaly rhizome, from which numerous, often densely arranged, erect, unbranched (rarely 1-2 branched) vegetative shoots and flowering stems arise; stems quadrangular, glabrous. Leaves (3-)4-6 pairs, sessile, dark green above, pale green below; blade elliptical, ovate or orbicular, subacute, the upper 17-50 x 12-25 mm, downwards smaller, with prominent midvein and 2-3 pairs of parallel curved side-veins; upper surface initially finely hairy, lower surface glabrous.
Inflorescence small and dense, terminal, umbel-like, subtended by (and forming a distinct pseudanthium with) 4 prominent white, ovate, subacute, 7.5-12 x 6.0-10 mm long bracts; pedicels in flower 1.3-1.5 mm, in fruit up to 2.5 mm, densely covered by appressed hairs. Flowers 10-30 (up to 8 maturing to fruits); calyx campanulate, 1.2-2 mm, with short teeth (0.2-0.7 mm) and dense cover of medifixed hairs; calyx tube with broadly triangular teeth, 1.2-1.7 mm; petals dark purple, 1.0-1.5 mm, narrowly triangular to lanceolate, subacute; anthers 0.6-0.8 mm, filaments 1.7-2.2 mm. Fruit broadly ellipsoid, (5-)8-11 x (5-)7.5-10 mm, bright red (rarely white), with a crown of calyx remnants; pyrene semiglobose, 3.5-4.5 x 3.0-3.5 mm, light brown, nearly smooth to slightly ribbed. - Early summer to mid-summer.
2n = 22 (F InL). [2n = 22]
Distribution. Nem-LAlp. Alt. N /Stranda/ above 1200 m. D locally common in NJy and western ØJy, scattered to rare in the rest of Jylland and in Sjæ; SJy Toftlund, FyL Enebærodde (extant), Egebjerggård 1892, LFM Møns Klint c. 1835, Ulfshale (latest 1959), Brn Almindingen 1817. N common in most areas from the coast into the low-alpine belt; scattered to rare in most of Op and He. S common in the southwest from northwestern Sk to northern BhG and eastwards to central SmI; scattered from northern Dls and northwestern Vg north to Hrj and Mpd; virtually absent from the inner parts of the southeast, but frequent along the coast from Gst to Ög, in particular in the archipelagos; Gtl Fårö, Eksta; on the whole common from western Hrj, Jmt and Ång northwards, but with uneven distribution and less frequent in many subalpine and most low-alpine areas. F frequent all along the coast and common in the northern mainland, scattered south to northern parts of EP, PH, PS and PK; in southern inland very rare, very few recent finds from EH and ES. Fa scattered on most of the larger islands, but absent in the northeast. I IVe scattered in coastal regions of the northern part of Snæfellsnes, INv rather common in coastal regions, INo rather common in coastal regions of outer areas in western part; IAu two localities in the northern part (Jökulsárhlið, Mjóifjörður).
Outside Norden in N England, Scotland, N Netherlands, N Germany, N Poland, W Estonia, N European Russia, Russian Far East, Alaska, Pacific and E Canada, S and SW Greenland.
Habitat. Open to semi-open places on mesic to moist ground. Edges of bogs and fens, shores of tarns and lakes; moist depressions and seepage areas in conifer, mixed and birch forest; coastal and mountain heath (in particular in the west). In the alpine belt isolated occurrences on bird cliffs; in the southeast especially at rock-pools and in fissures of coastal cliffs, sometimes in Alnus thickets; in D also in dune depressions.
2. Cornus mas L. Map
Linnaeus, Sp. pl.: 117 (1753). - Type: Linnaean Herbarium 151.2 (LINN), lectotype, sel. by Barrie & Reveal, Regnum Veg. 127: 38 (1993).
D Kirsebær-Kornel. F punamarjakanukka. Fa . I vorhyrnir. N bærkornell. S körsbärskornell.
Phanerophyte. Deciduous shrub or small tree up to 4 m, without running roots. Stems mostly erect, with opposite spreading branches; bark of twigs of the current year greyish green in winter, pubescent. Leaves pure green above, light green below; petiole 5-10 mm, canaliculate; blade elliptic to ovate, 4-10 x 2-5 cm, with 3-5 pairs of prominent, parallel side-veins; both surfaces sparsely set with appressed, medifixed hairs, lower side also with simple hairs in the vein angles; apex acute to abruptly acuminate; base cuneate to rounded.
Inflorescences umbel-like, terminal on last year’s short-shoots; bracts 4, greenish yellow, broadly ovate to elliptic, 10-12 mm; pedicels 5-8 mm. Flowers appearing before the leaves; calyx campanulate 0.8 - 1.0 mm, with c. 0.3 mm long triangular teeth and a dense cover of medifixed and simple hairs; petals bright yellow, 2-2.5 mm, lanceolate, acute; anthers 1-1.5 mm. Fruit pendent, broadly and obtusely ellipsoid, up to 14 mm long, scarlet, with a crown of remnants from the calyx teeth; pyrene ellipsoid, 12-15 x 6.5-8 mm, light brown, with 8 low ridges. - Early spring.
[2n = 18, 54]
Distribution and habitat. Grown for ornament north to southern N, middle S and southwesternmost F; very rarely escaped from cultivation, apparently spread by birds. D c. 10 localities in Njy, Vjy, ØJy and Sjæ. N VA Kristiansand **. S Srm Stigtomta and Stockholm 1990’s, Upl Lidingö 1998.
C and SE Europe, Turkey, the Caucasus.
3. Cornus sanguinea L. Map
Linnaeus, Sp. pl. 117 (1753). - Type: Clifford Herbarium 38, Cornus 1 (BM) lectotype, sel. by Jonsell & Jarvis, Nordic J. Bot. 22: 83 (2002). - Swida sanguinea (L.) Opiz (1832). Thelycrania sanguinea (L.) Fourr. (1868).
D Rød Kornel. F mustamarjakanukka. I dreyrahyrnir. N villkornell. S skogskornell.
Phanerophyte. Deciduous shrub or rarely a small tree, up to 4 m, with extensively running, superficial roots, from which numerous shoots appear. Stems erectopatent and somewhat arcuate with opposite branches; old stems up to c. 10cm thick; wood very hard and dense, white. Young branches reddish to violet (especially in winter time), shining, with appressed simple and medifixed hairs. Leaves dark green, slightly paler below, towards autumn strikingly dark red; petiole 3-18 mm, slightly canaliculate; blade ovate to broadly elliptic, 2.5-10 x 1.5-7.5 cm, with 3-5(-6) pairs of prominent, parallel side-veins; upper surface with scattered appressed, medifixed c. 0.3 mm long hairs, lower surface with dominating non appressed, simple, +- curved 0.5-1.0 mm long hairs, as well as some medifixed hairs; apex rather abruptly acuminate (sometimes subacute or rounded); base cuneate to rounded.
Inflorescences corymb- to umbel-like, on long peduncles; bracts very inconspicuous, adnate, caducous; pedicels 2-7 mm. Flowers 8-25; calyx campanulate, 1.2-2 mm, with short teeth (0.2-0.7 mm) and dense cover of medifixed hairs; petals dull white, 3.5-6.5 x 0.9-2.0 mm, narrowly triangular, subacute, slightly cucullate, with medifixed hairs on the back; anthers 1.3-2.3 mm, filaments 3.3-5.0 mm. Fruit not pendent, globose to subglobose, 5-9.5 mm, bluish black or black with scattered appressed hairs, and with a crown of remnants from the calyx teeth; pyrene globose to subglobose, 4.5-6.5 mm in diameter, greenish brown, with 8 or more low ridges. - Early summer to mid-summer.
[2n = 22]
Distribution. Nem- BNem. - Regarded as indigenous in the south; also cultivated and escaped. D fairly common in the islands (FyL, Sjæ, LFM, Brn) and in southeastern Jylland north to ØJy Århus, scattered further north; in VJy only Hampen, Hvejsel, Vejen and Klåbygård. N scattered at Oslofjorden (Ak, Bu), a few groups of localities further south and southwest: Øf Hvaler, Te Bamble, AA Tvedestrand and possibly Arendal (Elven 2005, Danielsen & Fægri XXXX); VA Kristiansand 2000 (probably escaped); escaped in Ho Bergen (first record 1868). S common in Öl, fairly common Gtl and Sk (except the inner north); elsewhere rare: eastern Bl, Klm Kristdala, central Ög (particularly Omberg), Vg (particularly Kinnekulle), BhG along the coast south to Uddevalla, eastern Dls; in Srm probably indigenous at least in Vårdinge (last seen 1974); also escaped or a relic of cultivation north to Vrm and Vsm. - Reports of escapes north of the area of established occurrences are generally not considered reliable, and not included here unless a voucher specimen has been seen. All records from F appear to be based on C. alba or C. sericea; all vouchers in H (from A, U, St, ES and PH) have been redetermined to C. alba.
Most of Europe outside Norden except Scotland and N Russia (subsp. sanguinea; all material seen from Norden represents this subspecies); in much of SE Europe and in Turkey, the Caucasus and N Iran represented by subsp. australis.
Habitat. Mesic to fairly dry, usually warm and rather light sites, often with shallow soil; wood margins, open broad-leaved deciduous woodland and wooded meadows; in scrub on rocks, precipices and screes. Calciphile.
Similar taxa. Cornus sanguinea has often been mixed up with C. alba or C. sericea; for instance, all presumed Finnish C. sanguinea specimens in the Botanical Museum in Helsinki turned out to be C. alba or C. sericea. C. sanguinea differs by the predominance of simple curved hairs (not medifixed) on the lower leaf surface, and has not more than 5 pairs of leaf veins (in the other species up to 7).
In D, subsp. australis (C.A. Meyer) Jáv. may occur as an escape from cultivation; that subspecies has a dominance of medifixed hairs on the lower surface of the leaves.
4. Cornus sericea L. Map Illustration
Linnaeus, Mantissa Alt: 199 (1771). - Cornus sericea L., Mantissa Alt.: 199 (1771). - Type: Linnaean Herbarium 151.6 (LINN) lectotype, sel. by Fosberg, Bull. Torrey Bot. Club 69: 585 (1942). - Thelycrania sericea (L.) Dandy (1957). - Swida sericea (L.) Holub (1967).
C. stolonifera Michaux (1803). - Thelycrania stolonifera (Michaux) Pojark. (1950). - C. alba subsp. stolonifera (Michaux) Wangerin (1910)
D . F lännenpensaskanukka. Fa . I sveighyrnir. N alaskakornell. S videkornell.
Phanerophyte. Deciduous shrub, up to 3 m, with extensively running roots from which numerous shoots arise. Stems procumbent to ascending with opposite, arcuate branches, up to 10 cm thick, lower ones often rooting. Young branches red-brown (in winter dark red to green), with medifixed hairs (mature branches glabrous). Leaves dark green above, glaucous below; petiole 20-40 mm, canaliculate; blade ovate to elliptic, 7-20 x 3-15 cm, with 5-7 pairs of prominent, parallel side-veins; both surfaces with appressed medifixed hairs, lower surface also with short simple hairs; apex tapering acuminate; base cuneate to rounded or rarely cordate.
Inflorescences corymb-like on long peduncles; bracts very inconspicuous, adnate, caducous; pedicels 2-5 mm. Flowers 20-50; calyx campanulate, 1.2-2 mm, with tapered teeth (up to c. 5 mm long) and a dense cover of medifixed hairs; petals dull white, 2.4-3.0 x 1.4-1.7 mm, oblong to lanceolate, subacute, slightly cucullate, with medifixed hairs on the back; anthers 1.2-1.5 mm; filaments 3.2-4.0 mm. Fruit not pendent, globose to subglobose, c. 7-8.5 mm diam., white to light blue with scattered appressed hairs, and with a crown of remnants from the calyx teeth; pyrene subglobose (usually somewhat wider than long) with broadly rounded base, 3.5-6 mm, light brown, with 8 low ridges. - Mid-summer.
[2n = 22]
Distribution. Introduced as an ornamental; mainly garden cultivars are planted nowadays, particularly ‘Flaviramea’ with yellowish branches in wintertime. - D frequently naturalized and increasingly spreading, particularly in NJy, ØJy and Sjæ; rarer in SJy and Brn. N escaped or naturalized in a number of places in Ak, and rarely in Op, He and along the coast north to MR. S naturalized and increasingly spreading at least north to Vg, Vsm and Upl; along the coast to southern Nb but probably only casual; not reported outside cultivation in Öl or Gtl. F most Finnish records of Cornus alba probably belong here; naturalized in the southwestern parts, in particular in eastern V, U and EH; finds documented by herbarium specimens north to PH Jyväskylä and east to ES Valkeala. I no records; rarely planted in parks and recreational areas.
North America, from Alaska to Labrador and south to the states around the Great Lakes and to N Mexico along the Rocky Mountains.
Habitat. Moist and wet, shady to semiopen places with rather rich soils; wood fringes, ravines, shore scrub along lakes and streams (often in Alnus glutinosa thickets); also on heaps and tips and among scrub in waste places. Clones may be very extensive due to running roots and procumbent, rooting branches, which may be detached and spread.
Similar taxa. Cornus sericea is very similar to C. alba. These two taxa are in recent floras most often treated as separate species rather than subspecies, being vicariant in north temperate to subarctic Asia and America, respectively, with no zone of contact. There is some confusion about the differentiating characters. The indumentum on the lower leaf surface is sometimes claimed to differ, but both taxa are fairly densely hairy, with appressed medifixed hairs, sometimes with a few unbranched hairs among them. The shape of leaves differ, although there is much overlap; C. sericea leaves may be considerably larger and are more distinctly acuminate, often tapering into a long apex. The length of the calyx teeth also gives some guidance. The most reliable character, besides the mode of growth, is the shape of the fruit stones (see fig.), easy to observe in herbarium specimens with dried-up fruits. This means, however, that much of the herbarium material is not possible to determine with full certainty.
5. Cornus alba L. Map Illustration
Linnaean Herbarium 151.5 (LINN) lectotype, sel. by Holub, Zpr. Cesk. Bot. Spol. 17: 4 (1982). - Swida alba (L.) Opiz (1838). - Thelycrania alba (L.) Pojark. (1950).
D Hvid Kornel. F idänpensaskanukka. Fa . I mjallarhyrnir. N sibirkornell. S rysk kornell.
Phanerophyte. Deciduous shrub, up to 3 m, with moderately running roots. Stems ascending to erect, with opposite, arcuate, non-rooting branches, up to c. 10 cm thick. Young branches red-brown, with medifixed hairs, in winter bright red, finally glabrous. Leaves dark green above, glaucous below; petiole 8-25 mm, canaliculate; blade ovate to elliptic, 4-8 x 3.5-5 cm, with 5-7 pairs of prominent, parallel side-veins; both surfaces with appressed medifixed hairs; apex rather abruptly and briefly acute to acuminate; base truncate to rounded.
Inflorescences corymb- to umbel-like, on long peduncles; bracts inconspicuous, adnate, caducous; pedicels 2-5 mm. Flowers 15-30; calyx campanulate, 1.2-2.0 mm, with short teeth (c. 0.3 mm) and a dense cover of medifixed hairs; petals dull white, c. 3.4 x c.1.4 mm, oblong to lanceolate, subacute, slightly cucullate, with medifixed hairs on the back; anthers 1.2-1.5 mm, filaments c. 3.5 mm. Fruit not pendent, globose, c. 6 mm, white to light blue with scattered appressed hairs, and with a crown of remnants from the calyx teeth; pyrene ellipsoid, cuneate at base, 5.0-5.8 x 3.5-4.5 mm, light brown, with 8 low ridges. - Mid-summer.
[2n = 22]
Distribution. Widely planted but rarely escaped. D widely used in lee plantations; in the wild usually found as a solitary shrub; rarely naturalized, more often a relic of cultivation, or a casual escape. Recorded from a few places in VJy, ØJy, FyL and Sjæ, but probably more frequent. N rarely escaped in the southeast (Øf, Ak, Op, Bu, Te) and in SF. S very few documented records, north to Srm, most of them relics of cultivation or on tips. F documented from St Karkku 1966, V Kimito 1948, U Nurmijärvi 1949, ES Lappeenranta 1957 and PH Jyväskylä 1969 (all misdetermined as C. sanguinea) and from railway areas in EP Vaasa and PS Iisalmi; apparently nowhere naturalized.
It is difficult to obtain a view of its status and distribution due to underrecording and confusion with C. sericea, but C. alba is much more rarely escaped, except perhaps in N.
N European Russia, Siberia east to the Ochotian Sea.
Habitat. Mesic to moist, semiopen places; wood fringes, tips, abandoned parks and gardens.
Similar taxa. Diagnostic characters of Cornus alba are discussed under C. sericea (4) and C. sanguinea (5).