Taxonomy
of Flowering Plants - LECTURE
NOTES - Fall, 1998
Hugh
D. Wilson - rm. 306,
Butler Hall
The Asteridae
Family Overview - Scrophulariales
Scrophulariaceae - the Snapdragon Family
Diversity: Mostly showy flowered
herbs with a few shrubs and some taxa specialized as root parasites - a
large and highly variable family of about 190 genera and 4, 000 species.
Distribution: Worldwide
with no pronounced center of diversity. We have 31 genera and 109 species
in the Texas flora, including several endemic
species from four genera.
Floral structure:
Significant features: This
family shows a floral structure similar to that found in the Lamiaceae
and Verbenaceae of the Lamiales.
It is characterized by the presence of a zygomorphic,
often bilabiate, corolla. Reduction
of stamen number is usually concordant with zygomorphy in that the fifth
stamen does not 'fit' into a corolla that shows bilateral symmetry.
However, as opposed to the Lamiales, taxa of the Scrophulariaceae
produce a capsular fruit, similar to
those produced by the Solanales. Thus, this family can be
consider as an 'intermediate' element of the Asteridae that fits
between the Solanales and the Lamiales.
Local Penstemon species:
(see also the Penstemon
website)
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laxiflorus
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cobaea
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murrayanus
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Castilleja indivisa:
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infloressssscence
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annotated
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flower
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calyx/corolla/gynoecium
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More information on the Scrophulariaceae
Return to Lecture
Notes, the Botany
201 homepage, or the Asteridae
page
