Pinaceae Family
- female cones (macrosporangiate strobili), which are usually called cones
- male cones (microsporangiate strobili), which are called catkins or pollen cones
- needlelike leaves
Pinaceae is the largest of the conifers. This includes number of species and individuals as well as being the most wide-spread and economically significant. The family consists of about 260 species and covers most of the boreal forests of the northern hemisphere, extending to one degree south of the equator into northern Indonesia. The largest genus is Pinus, which has about 120 species and subspecies and accounts for its huge geographic spread.
Pinaceae Genera
- Abies consists of about 55 species of true fir. Features include
- wide-base single needles;
- erect cones deciduous in one year;
- pollen grains with two wings.
- Cathaya consists of 1 species found in China. Features include:
- resembles Larix and Cedrus in that it has long and short shoots, but the cones develop on the long shoots and not the short ones;
- leaves are somewhat whorled and non-deciduous.
- Cedrus consists of 4 species of true cedar. Features include:
- long and short shoots;
- solitary erect male cones appear in late summer on the short shoots and are deciduous in one year;
- single leaves are arranged in false whorls, persisting for several years.
- Larix consists of 15 species of larch. Features include:
- long and short shoots;
- erect male cones appear on the leafless short shoots ripening in one year, but persisting and releasing seeds for a longer time;
- single leaves arranged in false whorls and deciduous in one year.
- Pseudolarix consists of 1 species of false larch found in China. Features include:
- same as Larix except for deciduous cones (that is mature cones breakup and release seed within one year);
- has 11 pairs of chromosomes (most of the pine family have 12 pairs).
- Keteleeria consists of 10 species found in China, Laos, Taiwan, and Vietnam.
- Features include: resembles Abies except the upright cones do not break up at maturity within one year;
- has hypogeal (underground) germination causing the cotyledons to stay below the ground surface where the true shoots emerge;
- pollen grains with two wings.
- Picea consists of 37 species of spruce. Features include:
- four-sided leaves arranged in spirals and set on a stem projection (the pulvinus) thus leaving a rough twig after falling;
- cones arise from the cluster of buds at the ends of the shoots and up to the time of pollination are erect but then become pendulous;
- pollen grains with two wings.
- Pinus consists of about 120 species of pine. Features include:
- needles in fascicles (of 1 to 8) which can be fit together to form a cylinder;
- female cones are fertilized in the second year and are variably persistent thereafter;
- male cones are many and clustered at the base of the current year's long shoots;
- cone seed scales usually with a scale shield (apophysis);
- pollen grains with two wings.
- Tsuga consists of 10 species of hemlock. Features include:
- leaves are notched and usually rounded at the ends with a bent petiole arising from a pulvinus and constricted at the base (the petiole);
- cones are small, ripening in the first year but remaining on the tree and not disintegrating;
- pollen grains without wings.
- Nothotsuga consists of 1 species of hemlock from SE China and often included in the Tsuga genus.
Note: There may be a 12th genus necessary for Mountain Hemlock (Tsuga mertensiana), now classified in the genus Tsuga (hemlock). Certain obstacles have arisen in classifying it with the genus Tsuga.
Some of these gross and microscopic morphological differences include:- larger cones;
- needles carried radially are thicker and longer than in other Tsuga species;
- stomata on dorsal and ventral surfaces as opposed to only on ventral surfaces for other Tsuga species;
- pollen grains with a pair of wings attached (same as pines, firs, and spruces) whereas other Tsuga species have bowl shaped pollen grains (like larch and Douglas-fir).
- Pseudotsuga consists of 8 species of Douglas-fir. Features include:
- leaves like Abies; cones like Picea and Tsuga, but with exserted bracts (little forked tabs at the ends of the cone scales); sharply pointed cylindrical buds;
- pollen grains without wings;
- has 13 pairs of chromosomes.
