Anatomia comparada das folhas e evolução das Podocarpineae
The anatomy of 112 species out of the 184 at present recognized is compared. The evolutionary sequence proposed shows in several different "series" the passage by successive transformations from an ancestral type with short one-nerved leaves, well-developed sub-epidermis and many resin canals to those with long wide leaves, first one-nerved then several-nerved, with reduced sub-epidermis and few resin canals. An over-evolved condition sometimes produces at the end of a "série" an apparent reversion to the ancestral type: leaves short or reduced to fleshy scales with late proliferation of canals separated in the mesophyll. A striking correlation between foliar anatomy and geographic latitude suggests, as with vascular evolution in seedlings at the cotyledon stage (WOLTZ, 1986), a greater age for the most southern taxa.
| Main Authors: | , , |
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| Format: | Digital revista |
| Language: | Portuguese |
| Published: |
Sociedade Botânica do Brasil
1987
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| Online Access: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33061987000200002 |
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