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{{Taxobox
| color = lightgreen
| name = Taxaceae
| image = Eibeyew1web.jpg
| image_width = 250px
| image_caption = ''A fleshy aril partly surrounds each seed in the <br>yews; note also immature cones with seed <br>not yet surrounded by the aril''
| regnum = [[Plantae]]
| divisio = [[Pinophyta]]
| classis = [[Pinophyta|Pinopsida]]
| ordo = [[Pinales]]
| familia = '''Taxaceae'''
| familia_authority = S.F. Gray
| subdivision_ranks = [[Genus|Genera]]
| subdivision =
'''Taxaceae''' ''sensu stricto''<br/>
''[[Taxus]]''<br/>
''[[Pseudotaxus]]''<br/>
''[[Austrotaxus]]''<br/>——<br/>
'''[[Cephalotaxaceae]]'''<br/>
''[[Torreya]]''<br/>
''[[Amentotaxus]]''<br/>
''[[Cephalotaxus]]''
}}
The family '''Taxaceae''', commonly called the '''yew''' family, includes three genera and about 7 to 12 species of [[conifer]]ous [[plant]]s, or in other interpretations (see Classification, below), six genera and about 30 species.
They are much branched, small [[tree]]s and [[shrub]]s. 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 [[Plant sexuality|dioecious]], rarely [[Plant sexuality|monoecious]]. The male [[conifer cone|cones]] are 2-5 mm long, and shed [[pollen]] in the early spring. The female cones are highly reduced, with just one ovuliferous scale and one seed. As the seed matures, the ovuliferous scale develops into a fleshy '''[[aril]]''' partly enclosing the seed. The mature aril is brightly coloured, soft, juicy and sweet, and is eaten by [[bird]]s which then disperse the hard seed undamaged in their droppings.
===Classification===
[[Image:Taxaceae.png|thumb|240px|left|Phylogeny of the Taxaceae and [[Cephalotaxaceae]] - note that both groups have evolved from within the other conifers]]
The Taxaceae is now generally included with all other conifers in the order '''[[Pinales]]''', as [[DNA]] analysis has shown that the yews are monophyletic with the other families in the Pinales (Chase ''et al''., 1993; Price, 2003), a conclusion supported by [[wikt:micromorphology|micromorphology]] studies (Anderson & Owens, 2003). Formerly they were often treated as distinct from other conifers by placing them in a separate order [[Taxales]].
The genera ''Torreya'' and ''Amentotaxus'', previously included in this family, are better transferred to the '''[[Cephalotaxaceae]]''', as genetic tests show they are more closely related to ''Cephalotaxus'' than to ''Taxus''. Alternatively, they may be included, with ''Cephalotaxus'', in a broader interpretation of Taxaceae as a single larger family (Price, 2003). In this sense, the Taxaceae includes six genera and about 30 species.
The differences between the Taxaceae and the Cephalotaxaceae are as follows:
<table border="" cellspacing="" cellpadding="">
<tr>
<th>Family</th><th> Taxaceae </th><th> Cephalotaxaceae </th>
</tr><tr>
<td> Cone aril </td><td> partly encloses seed </td><td> fully encloses seed </td></td>
</tr><tr>
<td> Cone maturation </td><td> 6-8 months</td><td> 18-20 months</td>
</tr><tr>
<td> Mature seed length </td><td> 5-8 mm *</td><td> 12-40 mm</td>
</tr><tr>
</table>
<nowiki>*</nowiki> To 25 mm in ''Austrotaxus''
A few botanists have transferred ''Austrotaxus'' to its own family, the '''Austrotaxaceae''', suggesting it may be closer to the '''[[Podocarpaceae]]''' than to the other Taxaceae, but genetic evidence does not support this transfer.
==References==
* Anderson, E. & Owens, J. N. (2003). Analysing the reproductive biology of Taxus: should it be included in Coniferales? ''Acta Hort.'' 615: 233-234. (conclusion is 'yes')<br>
* Chase, M. W. ''et al.'' (1993). Phylogenetics of seed plants, an analysis of nucleotide sequences from the plastid gene ''rbc''L. ''Ann. Missouri Bot. Gard.'' 80: 528-580.<br>
* Price, R. A. (2003). Generic and familial relationships of the Taxaceae from ''rbc''L and ''mat''K sequence comparisons. ''Acta Hort.'' 615: 235-237.
{{Pinophyta}}
[[Category:Taxaceae]]
[[Category:Conifers]]
[[Category:Plant families]]
| color = lightgreen
| name = Taxaceae
| image = Eibeyew1web.jpg
| image_width = 250px
| image_caption = ''A fleshy aril partly surrounds each seed in the <br>yews; note also immature cones with seed <br>not yet surrounded by the aril''
| regnum = [[Plantae]]
| divisio = [[Pinophyta]]
| classis = [[Pinophyta|Pinopsida]]
| ordo = [[Pinales]]
| familia = '''Taxaceae'''
| familia_authority = S.F. Gray
| subdivision_ranks = [[Genus|Genera]]
| subdivision =
'''Taxaceae''' ''sensu stricto''<br/>
''[[Taxus]]''<br/>
''[[Pseudotaxus]]''<br/>
''[[Austrotaxus]]''<br/>——<br/>
'''[[Cephalotaxaceae]]'''<br/>
''[[Torreya]]''<br/>
''[[Amentotaxus]]''<br/>
''[[Cephalotaxus]]''
}}
The family '''Taxaceae''', commonly called the '''yew''' family, includes three genera and about 7 to 12 species of [[conifer]]ous [[plant]]s, or in other interpretations (see Classification, below), six genera and about 30 species.
They are much branched, small [[tree]]s and [[shrub]]s. 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 [[Plant sexuality|dioecious]], rarely [[Plant sexuality|monoecious]]. The male [[conifer cone|cones]] are 2-5 mm long, and shed [[pollen]] in the early spring. The female cones are highly reduced, with just one ovuliferous scale and one seed. As the seed matures, the ovuliferous scale develops into a fleshy '''[[aril]]''' partly enclosing the seed. The mature aril is brightly coloured, soft, juicy and sweet, and is eaten by [[bird]]s which then disperse the hard seed undamaged in their droppings.
===Classification===
[[Image:Taxaceae.png|thumb|240px|left|Phylogeny of the Taxaceae and [[Cephalotaxaceae]] - note that both groups have evolved from within the other conifers]]
The Taxaceae is now generally included with all other conifers in the order '''[[Pinales]]''', as [[DNA]] analysis has shown that the yews are monophyletic with the other families in the Pinales (Chase ''et al''., 1993; Price, 2003), a conclusion supported by [[wikt:micromorphology|micromorphology]] studies (Anderson & Owens, 2003). Formerly they were often treated as distinct from other conifers by placing them in a separate order [[Taxales]].
The genera ''Torreya'' and ''Amentotaxus'', previously included in this family, are better transferred to the '''[[Cephalotaxaceae]]''', as genetic tests show they are more closely related to ''Cephalotaxus'' than to ''Taxus''. Alternatively, they may be included, with ''Cephalotaxus'', in a broader interpretation of Taxaceae as a single larger family (Price, 2003). In this sense, the Taxaceae includes six genera and about 30 species.
The differences between the Taxaceae and the Cephalotaxaceae are as follows:
<table border="" cellspacing="" cellpadding="">
<tr>
<th>Family</th><th> Taxaceae </th><th> Cephalotaxaceae </th>
</tr><tr>
<td> Cone aril </td><td> partly encloses seed </td><td> fully encloses seed </td></td>
</tr><tr>
<td> Cone maturation </td><td> 6-8 months</td><td> 18-20 months</td>
</tr><tr>
<td> Mature seed length </td><td> 5-8 mm *</td><td> 12-40 mm</td>
</tr><tr>
</table>
<nowiki>*</nowiki> To 25 mm in ''Austrotaxus''
A few botanists have transferred ''Austrotaxus'' to its own family, the '''Austrotaxaceae''', suggesting it may be closer to the '''[[Podocarpaceae]]''' than to the other Taxaceae, but genetic evidence does not support this transfer.
==References==
* Anderson, E. & Owens, J. N. (2003). Analysing the reproductive biology of Taxus: should it be included in Coniferales? ''Acta Hort.'' 615: 233-234. (conclusion is 'yes')<br>
* Chase, M. W. ''et al.'' (1993). Phylogenetics of seed plants, an analysis of nucleotide sequences from the plastid gene ''rbc''L. ''Ann. Missouri Bot. Gard.'' 80: 528-580.<br>
* Price, R. A. (2003). Generic and familial relationships of the Taxaceae from ''rbc''L and ''mat''K sequence comparisons. ''Acta Hort.'' 615: 235-237.
{{Pinophyta}}
[[Category:Taxaceae]]
[[Category:Conifers]]
[[Category:Plant families]]
