Sub-family Mimosaceae

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Family Fabaceae or Legume Family


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Fabaceae Commonly known as legume family 400 genera 10,000 species Found all over the world, concentrated in warm temperate regions (3rd largest family of flowering plants)


Fabaceae is composed of three different sub-families, namely P apillionaceae , Caesalpiniaceae and M imosaceae .

Sub-family Mimosaceae:

The family Mimosaceae includes about 40 genera, and at the same time has been considered to be the smallest one of all the three families of the order Leguminales . Sub-family Mimosaceae


Distribution: The plants of this family are almost exclusively tropical or sub-tropical in distribution. In our country this family is represented by many important genera, e.g., Acacia, Albizzia , Mimosa, Neptunia , Prosopis , Senegel , etc.


Habit They are either shrubs or trees very rarely herbs, sometimes climbers. Many of them are thorny and xeromorphic, e.g.. Acacia, Prosopis ; hydrophytes are also found, e.g., Neptunia oleracea . Mostly wild, but some are grown as sand binders to check soil erosion and desert extension.


Root : Tap and branched, deep rooted in the soil . Stem: Erect, branched, terete , woody, solid. The stem tissue is often rich in tannin-sacs and gum passages.


Leaves: Alternate, petiolate , usually the base of petiole is provided with pulvinus ; stipulate, usually stipules are modified into thorns; compound, pinnate and generally bipinnate . Leaflets entire, oval, obtuse, unicostate reticulate venation. Leaf movements are common, reaching a climax in the ultra-sensitivity of Mimosa pudica and Neptunia oleracea . In some Acacias from Australia the leaves are bipinnate and fall earlier. The petioles are being flattened and developing into phyllodes .


Inflorescence: Compound cymose heads. Flower: Usually sessile, actinomorphic, regular, hermaphrodite, bracteate , hypogynous , complete small, yellow, fragrant.


Calyx: 5 or 4, gamosepalous , the sepals are campanulate , more or less connate, green ( sepaloid ), small, inferior, aestivation generally valvate . Corolla: 5 or 4, free, gamopetalous , valvate , inferior, slightly united towards the base, usually pentamerous .


Androecium: Usually indefinite stamens , polyandrous, sometimes the number is reduced to ten or even four (e.g., in Mimosa pudica ). Stamens are attractive, bright coloured somewhat scented. Anthers minute, introrse , yellow, versatile . The filaments are long and slender. Gynoecium: Carpel one (monocarpellary); filiform , ovary superior, unilocular ; marginal placentation; style long; stigma minute and simple .


Fruit: Legume or lomentum . Seeds: Exalbuminous . Pollination: Usually through the agency of insects (entomophily ).

Lomentum or pod:

Lomentum or pod




Economic Importance of Mimosaceae : The sub-family is not of much economic importance. A few members are however useful . Gum arabic is obtained from the barks of A. nilotica (syn. A. arabica ) and A. Senegal. Saresh - a type of gum – is obtained from Albizzia lebbek . The bark of Acacia yields tannin which is used in leather tanning . The wood of Adenanthera is powdered and yields a red dye . Prosopis is grown as a hedge plant and also as a wind breaker in Rajasthan to check spreading desert, acts as water indicator . Durable timber is obtained from Acacia. Leaves and pods of Acacia and siris are used by some herbivores.

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