ENUMERATION OF CONIFERS 315 



elongated; umbo small, obtuse; seed dark gray, }/^ inch long. Europe to 

 western Asia and northeastern Siberia. — Early introduced into this country 

 and naturalized in some places on the New England coast. Hardy as far 

 north as Quebec and precariously so to Saskatchewan. Several garden 

 forms of comparativelj^ little importance are in cultivation. 



Var. argentea, Stev. Leaves light bluish-green of silvery hue. Var. aurea, 

 Beiss. Golden Scotch P. The young leaves golden-yellow, changing the 

 second year to green; of slow growth and rather dense habit. 



Var. fastigiata, Carr. (var. pyramidalis, Hort.). With ascending branches 

 forming a narrow pj-ramidal head. Var. Watereri, Rehd. (P. Wateriana, 

 Hort.). Waterer p. Dense columnar form with short steel-blue leaves, 

 f. pendula, Casp. With pendulous branches. Var. piunila, Beiss. Dwarf 

 globose bush. 



Of the geographical forms the best known and silviculturally of the most 

 importance is var. rigensis, Loud. A form with very red bark and straight 

 tall stem. Var. scotica, Beiss., is similar, but the bark is redder and the leaves 

 more glaucous and shorter, about 13^^ inches long. Var. lapponica, Fries {P. 

 lapponica, MajT), is a form of northern Europe. Of more narrow-pyramidal 

 habit: leaves broader and shorter, remaining green on the branches for four 

 to seven years: cones more yellowish. Var. engadinensis, Heer, is a form of 

 the higher mountains of Tyrol. Slow-growing pjTamidal tree with grayish- 

 green, thick and rigid leaves 1-1 H inches long. 



24. P. Mugo, Turra (P. montana. Mill.). Swiss Mountain P. Very 

 variable in habit, usually low, often prostrate shrub, sometimes pyramidal 

 tree to 40 feet tall, similar to the preceding; scales of winter-buds appressed; 

 branchlets usually of darker brownish color: leaves bright green, acutish, 

 stout, crowded, ^-2 inches long: conelet nearly sessile with mucronate scales; 

 cones tawny-yellow to brown, ovoid or conic-ovoid, %-^l4 inches long; 

 apophysis often pyramidal; umbo light gray, surrounded by a blackish ring. 

 An anatomical character in the leaves to distinguish this species from the 

 preceding is found in the cells of the epidermis which are of nearly equal 

 diameter, with a dot-like central space in P. sylvestris, but in this species 

 are much higher than broad with a dash-like central space. Mountains of 

 central and southern Europe, from central Spain to the Balkan mountains. — 

 Introduced into cultivation the second half of the eighteenth century. Hardy 

 as far north as eastern Canada and precariously so to Saskatchewan. Hand- 

 some low shrub with ascending branches densely clothed with bright green 

 foliage; well adapted to be planted as single specimens on the lawn or on 

 rocky slopes and as undergrowth in open woods. A very variable species, 

 usually divided according to the cones into the following four varieties or 

 subspecies. 



Var. Mughus, Zenari (P. montana var. Mughus, Willk. var. prostrata, 



