Pinus sp.

pine tree

 

Pinus sp.

L. 1753

pronounced: PY-nuss species

(Pinaceae — the pine family)

 

common name: pine

The modern English name pine comes to us from the Latin pinus via the French pin. Similar names are used in the other Romance languages. Before the 19th century, these conifers were often known as fir, from the Old Norse fyrre, via the Middle English firre. The old Norse name is still used for pines in some north European languages: Danish, fyr; Norwegian and Swedish, furu; German, Föhre; but in modern English it is now restricted to the Fir genus Abies and the Douglas-fir Pseudotsuga. Pines are native to most of the northern hemisphere. They have been introduced into the southern hemisphere, mostly into subtropical and temperate parts, where they are widely grown as a source of timber; and, as so often happens with introduced species, some are becoming invasive. The pine photographed is in Magnetic Street, Picnic Bay, near the recreation camp. I have not been able to identify which species of pine this is, as I have found no cones either on the tree or on the ground underneath.

Pines are evergreen and resinous trees, or occasionally shrubs, growing 3 – 80 m in height, with the majority of species 15 – 45 m tall. The smallest are the Siberian Dwarf Pine and the Potosi Pinyon, and the tallest is the Sugar Pine. Pines are long-lived, typically reaching ages of 100 – 1000 years, some even more. The longest-living is the Great Basin Bristlecone Pine, Pinus longaeva, one individual being reckoned, at 4,840 years old, to be one of the oldest living things on the earth.

The bark of most pines is thick and scaly, but some species have thin, flaking bark. The branches are produced in regular ‘pseudowhorls’, actually a very tight spiral, but appearing like a ring of branches arising from the same point. Many pines produce just one such whorl of branches a year, but some produce 2 or more. The spiral growth of branches, needles and cone scales are arranged in Fibonacci number ratios. The new spring shoots are sometimes called ‘candles’, and are covered in brown or whitish bud scales and point upwards at first, then later turn green and spread outwards. Pines have 4 types of leaves: (a) seed leaves (cotyledons) on seedlings, borne in a whorl of 4–24; (b) juvenile leaves, which follow immediately on seedlings and young plants. They are 2–6 cm long, single, green or blue-green, and arranged spirally on the shoot. These are produced for 6 months to 5 years, rarely longer; (c) scale leaves, similar to bud scales, small, brown and non-photosynthetic, and arranged spirally like the juvenile leaves; and (d) needles, the adult leaves, green, photosynthetic, bundled in clusters (fascicles) of 1 – 6 needles together. Each fascicle is produced from a small bud on a dwarf shoot in the axil of a scale leaf. The needles persist for anything up to 40 years, depending on the species. If a shoot is damaged, the needle fascicles just below the damage will generate a bud which can then replace the lost leaves.

Pines are mostly monoecious, although a few species are sub-dioecious, with individuals predominantly, but not wholly, single-sex. The male cones are small and only present for a short period, falling as soon as they have shed their pollen. They shed pollen when the conditions are right – the day at its warmest and the air at its driest. Pollen is not released during rain, as rain simply wipes the pollen out of the air. The wind carries the pollen to the female cones. These take 1½ - 3 years to mature after pollination, depending on the species, with actual fertilization delayed a year. Each cone has numerous spirally arranged scales, with 2 seeds on each fertile scale – the scales at the base and the tip of the cone being small and sterile, without seeds.

 

Photographs taken 2009, Picnic Bay
Page last updated 13th March 2019