Wednesday, September 23, 2009

Family Cucurbitaceae, Examples and its Economic Importance

It is gourd family.

VEGETATIVE CHARACTERS:

Plants are mostly annual or perennial weak stemed trailing or decumbent vines, usually climbing by means of tendrils and with plenty of juicy sap in the leaves and stems.

Root: Taproot, branched get thickened due to storage of food and water.

Stem: Herbaceous, climbing by means of tendrils or trailing, rooting at nodes, angular.

Leaf: Alternate brood, usually simple but often deeply lobed or divided and palmately veined, reticulate, petiole long and hollow. Tendrils may be simple or branched arising in the axil or opposite to the leaf at the node.

FLORAL CHARACTERS:

Inflorescence: Variable flowers often solitary. Large and showy or sometimes in racemes or cymes or in panides, unisexual, male and female borne on the same plant (monoecious e.g.: Luffa, cucumis) or on different plants (dioecious e.g.: Trichasanthes).

Flower: Regular, unisexual, rarely bisexual, smaller or large showy, white or yellow, epigymous.

Male flower: They are usually produced in much larger number, campamulate.

Calyx: Sepals five, fused, pointed, petaloid, campamulate, aestivation is imbricate.

Corolla: Petals five, fused (in momordica only at the base, in cucurbila throughout and campanulate), or free (Luffa) often deeply five lobed, valvate, imbricate, inserted on calyx tube when free. Form of corolla may be campanulate or rotate.

Androecium: usually 5 stamens, sometimes 3, free or combined to form a central column inserted on the calyx tube, anthers 2 called. Form of anthers bay be 1-lobed or 2-lobed, paired stamens have either 2-lobed or 4-lobed anthers.

Female flower: Female flowers are fewer than the male flower.

Calyx: Sepals 5, united, calyx tube adnate to the ovary and often produced beyond it.

Corolla: Petals 5, as in male free or slightly fused.

Staminoles: Rundiments of stamens 0 or 3 or 5.

Gynoecium: Tricapellary syncarpous, ovary, inferior, unilocular but often the placentae intrude far into the chamber of the ovary making the latter falsely trilocular. Most rarely the number to loculi may be one to ten.

Placentation axile but the ovules are not borne in the centre, style short, stingmas 3 often forked.

Fruit: Soft fleshy berry termed as pepo, generally indehiscent and sometimes of enormous size as in water melon or squash (Kadoo).

FLORAL FORMULA:

Male Flower: +, ♀, K(5), C5 or (5), A 5 or (2) + (2) + (1), G0

Female Flower: +, ♀, K(5), C5 or (5), A0 or 3-5 staminate, F(3).

FLORAL DIAGRAM:

FIGURE NO 166 PAGE 221 FIG 167 PAGE 122 ANGIOSPERM BY G. L. CHOPRA

e.g.: Pumbpkin (Ghia kadoo) or cucurbita pepo, cucumber or khara (cucumis sativus), Musk melon or kharbooz (cucumin melo), water melon (Hadwana), Ghiaturi (Luffa aegyptica).

ECONOMIC IMPORTANCE:

(1) They yield vegetables used in Kitchen,

(2) Some plants have medicinal value.

(3) Hard dried shells are used to form flasks as vessels and utensils.

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