Taxonomy
of Flowering Plants - LECTURE
NOTES - Spring, 1998
Hugh
D. Wilson - rm. 306,
Butler Hall
6 April 1998
The Asteridae
Order Overview - The Lamiales
According to Cronquest (1988) the Lamiales "may be briefly
characterized as Asteridae with a superior ovary consisting of 2 (-4) biovulate
carpels with twice as many uniovulate locelli as carpels. The fruit
very often consists of 1-seeded, half-carpellary nutlets." From
the point of view of field identification, this group of three families
is united by the common presence of a gynoecium that differs from those
previously considered (Gentianales, Solanales, Scrophulariales) in that
the number of ovules has been reduced to four and, via a 'derived' septum,
each ovule occuplies its own locule:
Synoptical Arrangement of
the Families of the Lamiales
1. Leaves mostly alternate, flowers actinomorphic,
stamens 5, stems terete, gynobasic style present..... Boraginaceae
1. Leaves mostly opposite, flowers zygomorphic,
stamens less than 5, stems usually quadrangular:
2. Style terminal or nearly so, the ovary only shortly or not at
all lobed at the top; plants seldom aromatic..... Verbenaceae
2. Style commonly gynobasic, uniting otherwise distinct lobes of
the ovary; plant usually aromatic..... Lamiaceae
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