Dwarf mountain pine [English], Krivulj, planinski bor [Serbian], Klek [Bulgarian], Klec [Czech], sosna gornaya [Russian], Bergkiefer, Krummholzkiefer, Bergföhre [German], Pin des montagnes [French], pino montano [Italian] (Jovanovic 1986, Businský 1998, M.P. Frankis field notes, Bulgaria 1998), sosna kosa, kosodrzewina [Polish].
Pinus mugo subsp. mugo is described on this page. A closely related pine taxon is treated either as a subspecies, P. mugo subsp. uncinata (Ramond) Domin, or as a separate species P. uncinata Ramond ex De Candolle. There is no consensus on this, with the two major recent studies of the complex differing in their interpretation, Christensen (1987) treating it as a subspecies, and Businský (1998) as a species; equally, each viewpoint has its adherents in review works, with Farjon (1998) following Christensen, and Richardson (1998) agreeing with Businský. The two taxa hybridise extensively, giving the hybrid subspecies P. mugo nothosubsp. rotundata (Link) Janchen et Neumayer (Businský 1998), alternatively P. × rotundata Link (Businský 1998).
Christensen (1987) gives a highly detailed synonymy with a nearly three page list of names which have been published (excessive use of names for inconsequential variation is a common problem with European pines); a brief summary of the most significant and commonly seen names is as follows (from Christensen 1987):
Pinus mugo subsp. mugo Turra: syns. P. montana Miller; P. mughus Scopoli; P. pumilio Haenke; P. mugo var. pumilio (Haenke) Zenari.
Pinus mugo subsp. uncinata (Ramond) Domin: syns. P. uncinata Ramond; P. mugo var. rostrata (Antoine) Hoopes.
Pinus mugo nothosubsp. rotundata (Link) Janchen & Neumayer: syns. P. rotundata Link; P. humilis Link; P. pseudopumilio (Willk.) Bech; P. obliqua Sauter; P. uliginosa Neumann ex Wimmer.
Shrub 1-3(-5) m tall, with one or more curved trunks; branches long, base laying on the ground (up to 10 m from base), with ± ascending or erect major branch ends; rarely a tree. Bark thin, ash-gray-brown to blackish-grey, splitting in angular scaly plates on old stems. Shoots uninodal, glabrous, greyish-black to deep red-brown grooved between the decurrent scale-leaves. Buds ovoid-conic, 6-9 mm, red-brown, very resinous. Leaves in fascicles of two (rarely three around apical bud of strong shoots), bright to dark green, often with a greyish tinge, straight to slightly twisted, minutely serrulate, 23-75 mm long, 0.9-2.1 mm wide, leaf sheath persistent, grey, 15-18 mm. Leaves persistent (2-)4-9(-10) years. Plants usually monoecious, rarely subdioecious. Male cones 10 mm, yellow or red, pollen shed May to July. Female cones purple ripening matte dark brown in late September to October 15-17 months later and opening then, or (if covered by winter snow first) the following spring; sessile or nearly so, symmetrical, 18-55 mm long, 14-28 mm wide (closed), opening to 25-45 mm, angle of inclination to stem 90°-130°; apophysis thin, flat, flexible, 6-10 mm wide and 1-2 mm thick, rhomboidal with a sharp transverse keel, rarely moderately thickened to pyramidal; umbo central, 3-4 mm wide. Seed black, 3-4 mm with a 7-12 mm wing buff with darker streaks; cotyledons (3-)5-7(-8). Cones shed soon after seed release or up to a year or two later. (Jovanovic 1986, Christensen 1987, M.P. Frankis, field notes and herbarium material, Bulgaria 1998).
C & SE Europe, east from the central Alps near the Swiss-Austrian border, the Erzgebirge east to the Carpathians and southeast through Yugoslavia and Romania to the Rila and Pirin Mts of Bulgaria, with an isolated population in the central Italian Apennines, and outliers within the range of subsp. uncinata west to the Vosges and French Alps (Christensen 1987). It grows at altitudes of 1400-2500+m, mostly in the high subalpine region at and above the timberline, but also at lower altitudes in peat bogs and frost hollows, exceptionally as low as 200 m in SE Germany and S Poland (Jovanovic 1986, Christensen 1987). Highest altitudes are reached in the extreme S of its range in the Pirin Mts of SW Bulgaria, where it reaches at least 2700 m (M.P. Frankis field notes and herbarium material, Bulgaria 1998). It occurs in Croatia, where it is protected by law. Hardy to Zone 3 (cold hardiness limit between -39.9°C and -34.4°C) (Bannister and Neuner 2001).
The species is also naturalized in Canada: Alberta, British Columbia, Ontario, and Québec; and the USA: Massachusetts, Michigan, Minnesota, New Hampshire, and Wisconsin (PLANTS database 2009.03.31).
Not worth mentioning!
Used to protect soil against erosion and to retard avalanching. Wood hard, heavy. Needles are the source of oil (Jovanovic 1986), and are also used for a (delicious!) herbal tea in Bulgaria (M.P. Frankis field notes, Bulgaria 1998). As an ornamental it is very popular with rock and landscape gardeners, particularly in Scadinavia, Holland and Germany, where it is widespread in municipal parks and gardens (Businský 1998; M.P. Frankis, pers. obs.). USDA hardiness zone 4.
Very easy to see around the top stations of ski lifts in Austria, Bulgaria and elsewhere in central and SE Europe; it is usually abundant and covers large areas at and above the treeline.
The low shrubby growth with a bowed basal section of stem is an adaptation to deep snow cover and avalanches; the erect branch ends are flattened down by the weight of snow, to spring erect again during the spring thaw; see Berkutenko (1993) for a discussion of this phenomenon with regard to the similar growth structure of Pinus pumila. The Bulgarian name Klek ('knee') refers to the growth form.
Very rarely plants with cone characters of subsp. mugo make small trees with a straight stem, but only where sympatric with either subsp. uncinata or hybrids with it, suggesting tree form is due to hybrid influence (Christensen 1987).
Berkutenko, A. 1993. The remarkable Pinus pumila. Int. Dendrol. Soc. Yearbook 1992: 41-46.
Businský, R. 1998. Pinus mugo agg. in former Czechoslovakia - taxonomy, distribution, hybrid populations and endangering. Zprávy Ces. Bot. Spolec. Praha 33: 29-52. [in Czech; brief English summary].
Christensen, K.I. 1987. Taxonomic revision of the Pinus mugo complex and P. × rhaetica (P. mugo × sylvestris) (Pinaceae). Nordic J. Botany 7: 383-408.
Jovanovic, Branislav. 1986. "Pinus mugo" in Flora Srbije. Belgrade: Serbian Academy of Sciences and Arts.
Turra, A. 1765. Dei vegetabili di Monte Baldo. Giorn. Italia Sci. Nat. 1:152.
This page co-edited with M.P. Frankis, 1999.02. Additional thanks to Milan Jovanovic for information and assistance contributed 1999.02.
Last Modified 2017-08-13