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Fabaceae |
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The traditional Leguminosae or Fabaceae is treated in your textbook as one family with three subfamilies but by Cronquist as 3 families All have a single, simple, superior carpel. Ovules vary from 2 to many and occur in alternating rows on either side of the carpel opening (suture); marginal placentation Flowers are usually perfect Leaves alternate, often pinnately compound, less often palmately compound or simple The fruit is a "legume" by definition, but there is enormous variation in the morphology of fruits that are produced from the single carpel; basically a follicle The seeds lack endosperm Most legumes have root nodules containing nitrogen-fixing bacteria Enormous economic importance, second only to Grass Family for food. Also many ornamental plants - See Table in textbook
Subfamily Mimosoideae Flowers: Actinomorphic; stamens usually 10 or more, pollen in pollinia; calyx, corollas, and filaments connate & often with tubes (but free from each other) Inflorescences: Capitate clusters, spikes or racemes Fruits: Typically a legume - dry and dehiscing along both sutures Seeds: Without endosperm, often with a U-shaped groove (pleurogram) or pits Habit: Mostly tropical and subtropical trees; a few temperate shrubs and herbs Leaves: Bipinnately compound, alternate, with a pulvinus, some show movement, stipules present; beltian bodies in some species Examples:
Subfamily Caesalpinioideae Flowers: Zygomorphic; petals, sepals, and stamens usually free; hypanthium present; banner petal internal to lateral petals; stamens 10 (or fewer); anthers often opening by pores Inflorescences: Mostly racemes or spikes Fruits: Legumes, dry, dehiscent along both sutures or breaking into loments Seeds: Without endosperm, often hard and with an O-shaped groove (pleurogram) Habit: Tropical and subtropical trees and shrubs, few temperate trees and herbs Leaves: Pinnately or bipinnately compound, sometimes appearing simple; alternate; stipules present; with a pulvinus Examples:
Subfamily Faboideae Flowers: Zygomorphic, papilionaceous; hypan-thium present; petals 5 [1 banner or standard petal outermost, 2 free lateral wing petals, and 2 petals fused to form the keel]; stamens 10, usually diadelphous (9 connate, 1 free), sometimes monadelphous or all free Inflorescences: Racemes, spikes, or heads Fruits: Diverse legumes Seeds: Without endosperm; lacking pleurogram Habit: Mostly herbs, some trees and shrubs; temperate, subtropical, and tropical Leaves: Usually pinnately compound, sometimes palmately compound, rarely simple, alternate, with stipules Note: This subfamily is sometimes called the "Papilionoideae." Examples:
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