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22-year-old Table Mountain Pine - Morton Arboretum Specimen started from seed
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| Table Mountain pine (Pinus pungens) is also called hickory pine, mountain pine, or prickly pine. It is most often small in stature, poor in form, and exceedingly limby. One large tree near Covington, VA, measures 70 cm (28 in) in d.b.h. and 29.6 m (97 ft) tall and has a crown spread of 10.4 m (34 ft). These pines are used locally for fuel and commercially for pulpwood, and they provide valuable watershed protection. The species epithet pungens derives from the Latin for "sharp-pointed", a reference to the characteristic stout hooked points on the cones (fig.1). Table Mountain pine, an Appalachian endemic, grows almost entirely within the range of pitch pine (Pinus rigida) and Virginia pine (P. virginiana), but is less frequent. In general, Table Mountain pine occupies xeric sites of Appalachian rocky and shaly mountainous areas from Georgia into Pennsylvania. It is frequently found on ridges of the precipitous gorges that dissect the Blue Ridge Mountains. Damaging Agents- Weather-related factors such as high gusty winds, glaze, heavy wet snowfall, cloudbursts, tornadoes, and lightning have been known to damage stands and isolated trees of Table Mountain pine. The most serious diseases of Table Mountain pine are Phaeolus schweinitzii, which causes butt and root rot, and Phellinus pini, which causes heartrot in older or damaged trees. Dioryctria yatesi, a cone-boring insect, can in some years destroy entire local seed crops. Periodically, the southern pine beetle, Dendroctonus frontalis, decimates entire stands. The European pine sawfly, Neodiprion sertifer, at times defoliates trees of their previous year's needles, but seldom kills the trees. Trees of all sizes, from 3-year-old seedlings to mature specimens, are attacked by the pine twig gall scale, Matsucoccus gallicola, which causes bark to swell and crack, killing foliage and tree. Table Mountain pine is used commercially for pulpwood, low-grade sawtimber, and firewood. The serotinous cones on many trees make seed available for wildlife on a year-round basis. Many of the short stubby limbs seen on Table Mountain pine are caused by squirrels that prune off the cone-bearing section of the limb to get at seed in the heavily armed cone cluster. Also, the heavy heath layer in Table Mountain pine stands provides plentiful wildlife food and cover (16,31). The often gnarly Table Mountain pines are a welcome sight on rocky, cliff-like areas of the Appalachians, but perhaps the most important use of the species is as protection forest; it stabilizes soil, minimizing erosion and runoff from the vast shale barrens and other rugged topographic features within its natural range. (2)
| Animals, chiefly squirrels, make use of this tree for food and shelter: "Using its teeth, the red squirrel, Tamiasciurus hudsonicus, will cut a cone-bearing branch from the tree. Once on the ground, the cone is removed from the branch in the same manner. One by one, the squirrel chews away cone scales from the base to the apex of the cone and consumes the seeds inside. Because of this activity, Pinus pungens has locally been dubbed 'squirrel pine'". (1) | |
Figure 1. pungens refers to the sharp points on the cones
Flowering and Fruiting- Table Mountain pine is monoecious. Cones are commonly seen on trees of sapling size and minimum seed-bearing age is 5 years. In northwestern North Carolina, pollen release at 457 m (1,500 ft) elevation begins the last week of March and ends during the first week of April; at 762 m (2,500 ft), pollen release begins about the second week in April and ceases near the end of the third week. Growth and reproductive activities of Table Mountain pine generally occur as early as, or earlier than, those of associated species (31). Table Mountain pine is reproductively isolated from other pine associates by early pollen release, so hybridization is restricted. The staminate cones of Table Mountain pine are a reddish purple. The pollen is very large for eastern pines, being 50.2 ± 4.6 µ in inside diameter. The cone is heavy and egg shaped; the scales are much thicker at the ends and are armed with stout, hooked spines. Young ovulate strobili have a peduncle about 1 cm (0.4 in) long which is visible at maturity; as branch diameter increases, cones appear sessile. From two to seven cones are often arranged in whorls on branches, around the stems of saplings, or on leaders (21,25). Cones average 72 mm (2.8 in) in length, ranging from 42 to 103 mm (1.7 to 4.1 in); 54 mm (2.1 in) in width, ranging from 33 to 75 mm (1.3 to 3.0 in); and 64 cm³ (3.9 in³) in volume, ranging from 27 to 134 cm³ (1.6 to 8.2 in³). Cone dimensions and degree of serotiny decrease with increased elevation. Cones are largest at northern latitudes. In general, cones at higher elevations are well developed. Immature cones are deep green to brown, ripe cones are lustrous light brown, and old cones retained on branches are gray. |
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