Taxonomy
of Flowering Plants - LECTURE
NOTES - Spring, 1998
Hugh
D. Wilson - rm. 306,
Butler Hall
6 April 1998
The Asteridae
Family Overview - Lamiales
Verbenaceae - the Vervain or Verbena Family
Diversity: Shrubs, trees,
and herbs with the latter predominating in our flora - about 100
genera and 2, 600 species.
Distribution: Worldwide,
but as opposed to other elements of the Lamiales, with greatest diversity
in the tropics. We have 14 genera and 69 species in the Texas flora, including
a single endemic
species in South Texas.
Floral structure:
Significant features: This
family carries the distinctive gynoecium of the Lamiales
in that the ovary usually shows a second septum, producing 4 locules
and each of these has only a single seed. However, the lobing in
most taxa is not as extensive as that found in the Boraginaceae and Lamiaceae
and the style is not gynobasic, it is usually positioned at the
tip of the ovary. Taxa of the Verbenaceae, especially
the herbs, tend of show quadrangular stems
and all have opposite leaves.
This similarity to the Lamiaceae also extends to corolla
zygomorphy but this is less developed in the Verbenaceae and
usually expressed as an asymmetry in the corolla lobes as opposed to the
bilabiate ('two-lipped') corolla configuration common among the mints..
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Lantana includes
of ca. 150 shrubby species, mostly from the American tropics. Our
flora includes native wild species and 'escapes' from cultivation.
Note weak zygomorphy (one petal lobe larger than the others) characteristic
of the family |
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Verbena:
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ornamental hybrid
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racemose inflorescence
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capitate inflorescence
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Callicarpa americana:
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at anthesis
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just past anthesis
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fruit - mid summer
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mature fruit
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More information on the Verbenaceae
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