Everything about Pinaceae totally explained
The family
Pinaceae (
pine family), is in the order
Pinales and includes many of the well-known
conifers of commercial importance such as
cedars,
firs,
hemlocks,
larches,
pines and
spruces. It is the largest conifer family in species diversity, with between 220-250 species (depending on
taxonomic opinion) in 11 genera, and the second-largest (after
Cupressaceae) in geographical range, found in most of the
Northern Hemisphere with the majority of the species in temperate climates but ranging from subarctic to tropical. One species just crosses the
equator in southeast Asia. Major centres of diversity are found in the mountains of southwest
China, central
Japan,
California and
Mexico.
They are
trees (rarely
shrubs) growing from 2 to 100 m tall, mostly
evergreen (except
Larix and
Pseudolarix,
deciduous), resinous, monoecious, with subopposite or whorled branches, and spirally arranged, linear (needle-like) leaves. The female
cones are large and usually woody, 2-60 cm long, with numerous spirally-arranged scales, and two winged
seeds on each scale. The male cones are small, 0.5-6 cm long, and fall soon after pollination; pollen dispersal is by
wind. Seed dispersal is mostly by wind, but some species have large seeds with reduced wings, and are dispersed by
birds. The embryos are multi-cotyledonous, with 3-24
cotyledons.
Classification
The 11 genera are divided into four subfamilies, based on the cone, seed and leaf morphology:
- Cones biennial, rarely triennial, with each year's scale growth distinct, forming an umbo on each scale. Cone scale base broad, concealing the seeds fully from abaxial view. Seed without resin vesicles. Seed wing holding the seed in a pair of claws. Leaves with primary stomatal bands adaxial (above the xylem) or equally on both surfaces. Subfamily Pinoideae (Pinus)
- Cones annual, without a distinct umbo. Cone scale base broad, concealing the seeds fully from abaxial view. Seed without resin vesicles, blackish. Seed wing holding the seed loosely in a cup. Leaves with primary stomatal bands adaxial (above the xylem) or equally on both surfaces. Subfamily Piceoideae (Picea)
- Cones annual, without a distinct umbo. Cone scale base broad, concealing the seeds fully from abaxial view. Seed without resin vesicles, whitish. Seed wing holding the seed tightly in a cup. Leaves with primary stomatal bands abaxial (below the phloem vessels) only. Subfamily Laricoideae (Larix, Cathaya, Pseudotsuga)
- Cones annual, without a distinct umbo. Cone scale base narrow, with the seeds partly visible in abaxial view. Seed with resin vesicles. Seed wing holding the seed tightly in a cup. Leaves with primary stomatal bands abaxial (below the phloem vessels) only. Subfamily Abietoideae (Abies, Cedrus, Pseudolarix, Keteleeria, Nothotsuga, Tsuga)
Further Information
Get more info on 'Pinaceae'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://pinaceae.totallyexplained.com">Pinaceae Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |
