Cephalotaxaceae
| Cephalotaxaceae | |
|---|---|
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| Cephalotaxus harringtonii | |
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| Family: | Cephalotaxaceae |
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The family Cephalotaxaceae is a small grouping of conifers, with three genera and about 20 species, closely allied to the Taxaceae, and included in that family by some botanists. They are restricted to east Asia, except for two species of Torreya found in the southwest and southeast of the USA; fossil evidence shows a much wider prehistorical northern hemisphere distribution. The differences between the two families are as follows:
| Family | Taxaceae | Cephalotaxaceae |
|---|---|---|
| Cone aril | partly encloses seed | fully encloses seed |
| Cone maturation | 6-8 months | 18-20 months |
| Mature seed length | 5-8 mm * | 12-40 mm |
* To 25 mm in Austrotaxus
These are much branched, small trees and shrubs. The leaves are evergreen, spirally arranged, often twisted at the base to appear 2-ranked. They are linear to lanceolate, and have pale green or white stomatal bands on the undersides. The plants are monoecious, subdioecious or dioecious. The male cones are 4-25 mm long, and shed pollen in the early spring. The female cones are reduced, with one to a few ovuliferous scales, and one seed on each ovuliferous scale. As the seed matures, the ovuliferous scale develops into a fleshy aril fully enclosing the seed. The mature aril is thin, green, purple or red, soft and resinous. Each ovuliferous scale remains discrete, so the cone develops into a short stem with one to a few berry-like seeds. They are probably eaten by birds or other animals which then disperse the hard seed undamaged in their droppings, but seed dispersal mechanisms in the family are not yet well researched.