Jump to content

Cephalotaxaceae

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by MPF (talk | contribs) at 13:56, 25 April 2005 (update taxobox, odds'n'ends). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Template:Taxobox begin Template:Taxobox begin placement Template:Taxobox regnum entry Template:Taxobox divisio entry Template:Taxobox classis entry Template:Taxobox ordo entry Template:Taxobox familia entry Template:Taxobox end placement Template:Taxobox section subdivision Cephalotaxus
Cephalotaxus fortunei
Cephalotaxus griffithii
Cephalotaxus hainanensis
Cephalotaxus harringtonia
Cephalotaxus koreana
Cephalotaxus lanceolata
Cephalotaxus latifolia
Cephalotaxus manni
Cephalotaxus oliveri
Cephalotaxus sinensis
Cephalotaxus wilsoniana
Amentotaxus
Amentotaxus argotaenia
Amentotaxus assamica
Amentotaxus formosana
Amentotaxus poilanei
Amentotaxus yunnanensis
Torreya
Torreya californica
Torreya fargesii
Torreya grandis
Torreya jackii
Torreya nucifera
Torreya taxifolia Template:Taxobox end

The family Cepahlotaxaceae 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.