Note on Family-Leguminosae

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source:www.biologydiscussion.com

This is one of the largest family of dicotyledon which includes about 600 genera and 13000 species.The members are found in all possible habitats of trophics, sub-trophics and temperate regions of the world. Depending on the characters of corolla and androecium, this family is divided into 3 subfamilies;

  • Papilionoideae (Papilionaceae)
  • Caesalpinioideae ( Caesalpiniaceae)
  • Mimosoideae (Mimosaceae)

Family: Papilionaceae (Pea family)

Class: Dicotyledonae

Sub-class: Polypetalae

Series: Calyciflorae

Order: Rosales

Family: Leguminosae

Common name: Papilionaceae

Distribution:

The family includes about 482 genera and 7200 species. The members are cosmopolitan in distribution. Thus, they are found in diverse habitats of trophics, sub-trophics temperate and even sub-alpine regions. Many of the vegetables and pulses plants are included in this family. Thus is considered as the economically important family.

Vegetative character:

Habit

Annual, biennial or perennial herbs (Pisum, Vicia), undershrubs(Crotolaria alba), Shrubs(Cajanus), trees(Dalbergia, Pterocarpus) or climbers(Lathyrus), mostly terrestrial, sometimes aquatic.

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Root

Well established branched taproot system inhabited by nitrogen-fixing Rhizobium bacteria forming root nodules to increase the fertility of the soil.

Stem

Aerial, sometimes submerged, erect or creeping or climbing the support with distinct nodes and internodes branched, herbaceous or woody, cylindrical or angular or flattened, solid or fistular, pubescent or glabrous.

Leaf

Cauline and ramal, stipulate, sometimes ex-stipulate. Stipules are foliaceous(large leaf-like)(Pisum), Alternate, sometimes opposite or whorled, small or pinnately compound or palmately compound, in pinnately compound leaf upper leaflets may be modified into leaf tendrils(Lathyrus, Pisum), unicostate or multicostate reticulate venation.

Floral characters

Inflorescence

Racemose, terminal or axillary raceme (Pisum) or spike(Urania) or panicle (branched raceme or spike)(Dalbergia), sometimes solitary also.

Flower

Bracteate, rarely ebracteate, pedicellate or sessile, complete, bisexual, zygomorphic, hypogynous, pentamerous, papilionaceae.

Calyx

Sepals(5), gamosepalous, unequal size, valvate aestivation, sometimes imbricate, odd sepal anterior, persistent inferior.

Corolla

Petals1+2+(2), 3 polypetalous, 2 gamopetalous, vexillary aestivation(presence of five unequal sized petals posterior largest petal known as vexillum or standard, partially overlap 2 lateral medium sized petals known as wings or alae which overlap 2 anterior smallest fused petals known as keels or carina, inferior.

Androecium

Stamens 10, diadelphous either 1+ (9) in Pisum sativum or (5)+(5) in Smithiana or sometimes monadelphous either(9) in Dalbergia or (10)in Arachis hypogea, rarely polyandrous(sophora), anthers dithecous, basifixed or dorsifixed, introrse, inferior.

Gynoecium

Carpel1, monocarpellary, ovary superior, unilocular with many ovules in marginal placentation, ovary elongated somewhat flattened, style simple or bent, stigma normally simple.

Floral formula

Br % K((5) C1+2+(2) A(10)

Economic Importance

Vegetables and Pulses

Cajanus cajan (Pigeon pea)

Pisum sativum (Pea)

Vicia faba (Broad bean)

Cicer arietinum (Gram)

Phaseolus aureus (Green gram)

Oil-yielding plants

Arachis hypogea (Groundnut)

Glycine man (Soybean)

Timber plants

Dalbergia sissoo (Sissow)

Pterocarpus marsupium (Indian kino tree)

Ornamental plants

Lathyrus Odoratus (Garden pea)

Saphora japonica (Japanese pagoda tree)

  •  The members are cosmopolitan in distribution. Thus, they are found in diverse habitats of trophics, sub-trophics temperate and even sub-alphine regions. 
  • Many of the vegetables and pulses plants are included in this family. Thus is considered as the economically important family.
  • This is one of the largest family of dicotyledon which includes about 600 genera and 13000 species.
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