CUCURBITACEAE

FAMILY OF THE WEEK : CUCURBITACEAE
In India around 37 genera and 97 species,several of which are cultivated throught India. The chief centre of distribution is however East Himalayas.Gourd,Bottle gourd,Cucumber,Red pumpkin and melon are common species known in cultivation.
Vegetative characters:
Succulent,trailing or decumbent annual or perennial herbs, usually climbing by means of tendrils. The tendrils are lateral spirally coiled,simple or variously branched structures.
The stem is usually five angular. The leaves are alternate, long petioled,frequently cordate, simple but often palmately or pinnately lobed or divided and palminerved.Stipules are absent.
Inflorescence and flowers:
Flowers are usually solitary or in cymose inflorescence.The plants are monoecious or dioecious. The flowers are yellow or white, unisexual, actinomorphic, pentamerous and epigynous.The calyx is of five sepals forming a tube adnate to the ovary in female flowers.The aestivation is imbricate or valvate. The corolla is of five petals which are united in a tube or nearly quite free. The corolla is campanulate, rotate or salverform, and the lobes are imbricate.
The androecium shows much variation consisting of basically 5 distinct to completely connate stamens that frequently are twisted, folded or reduced in number.
The gynoecium consists of a single compound pistil of 2-5 carpels, generally with one style and as many style branches or major stigma lobes as carpels, and an inferior ovary with one locule and usually numerous ovules on 2-5 parietal placentae or 3 locules with numerous ovules on axile placentae.
The fruit is a fleshy berry-like with soft or hard pericarp. This type of fruit is called pepo.
The seeds are often packed in a pulp or fibre.
Pollination is by insects for nectar secreted by nectariferous disc.
The seeds are dispersed by explosive opening of fruit or by animals and birds.
Examples:
The family provides a large number of fruits which are eaten raw or cooked.
Luffa cyllindrica(L.) syn Luffa egyptiaca. Gourd.
Luffa acutangula Roxb.
Lagenaria siceraria; Lageneria vulgaris(Bottle gourd;Lauki)
Cucumis sativus L.(Cucumber,Khira)
Cucumis melo L.(Melon,Kharbuz)
Cucumis melo L.variant momordica(Phut)
Cucumis melo L. var. utilissimus (Kakri)
Citrullus lanatus;Citrullusvulgaris (Watermelon,Tarbuz)
Cucurbita moschata (Pumpkin)
Cucurbita maxima (Red pumpkin)
Cucurbita melo (Field pumpkin)
Binincasa hispida (White gourd;Petha)
Momordia charantia (Bitter gourd;Karela)
Trichosanthes anguina (Snake gourd;Chachinda)
Trichosanthes dioica Roxb.(Pointed gourd;Padwal)
Coccinia cordia;Coccinia indica (Ivy gourd)

CONVOLVULACEAE

Ipomoea carnea(Besharam)


Ipomoea quamoclit(Ganesh vel)


Evolvulus alsinoides(Vishnukrant)


Argyria cuneata


FAMILY OF THE WEEK : CONVOLVULACEAE
In India about 20 genera and 158 species occuring chiefly in southern and western India.
Vegetative characters:
Mostly herbs or shrubs often twining and very rarely trees.
The species of cuscuta are leafless and rootless total parasite with threadlike twinning stem which draws food material from host through suckers.
Sometimes as in Ipomoea batatas, the roots store great quantities of food and become thick and fleshy.The plants often contains latex.
The leaves are alternate,exstipulate,simple,sometimes pinnately(I.quamoquilt) or palmately(I.pes-tigridis) divided. In cuscuta the leaves are reduced to small scales.
Inflorescence and flowers:
The inflorescence is an axillary cyme or sometimes the flowers are solitary as in Calystegia.
The flowers are bracteate and the bracts are in pairs or sometimes forming an involucre as in Ipomoea pes-tigridis. They are often showy, perfect, bisexual,actinomorphic,pentamerous and hypogynous.
The calyx is deeply five lobed, persistent and sometimes enlarged in fruit. The corolla is gamopetalous, five lobed, campanulate,funnel shaped or subglobose.
The stamens are five epipetalous at the base. The anthers are oblong, diathecous, introrse and dehiscing longitudinally.
The gynoecium is bicarpellary and syncarpous with a superior ovary. The style is filiform and one but in Cuscuta there are two styles. The stigma is capitate, bilobed or two branched.
A ring like or cup shaped nectariferous disc present at the base of the ovary is often lobed.
Fruit is usually four or two valved capsule.The seeds are smooth or hairy.
Bright and showy flowers favor insect pollination.Funnel shaped flowers of Ipomoea are visited by nectar sucking birds.The seeds are dispersed by birds and animals.
Examples :
Ipomoea
Argyreia(Wooly morning glory)
Calonyction
Porana

COMMELINACEAE

Commelina benghalensis

Commelina forsskalaei

Murdannia lanuginosa

Cyanotis

FAMILY OF THE WEEK:COMMELINACEAE
It is a monocot family.
In India 10 genera and 76 species found in southern and western India and tropical eastern Himalayas.
Vegetative characters:
Annual or perennial succulent herbs with knotted stems. Occasionally twinning herbs.
Roots are fibrous; sometime much thicker and tuberous.
Leaves alternate, entire,ovate lanceolate or linear,parallel veined and usually with a closed basal membranous sheath. Calcium oxalate crystals are often present in the tissues.
Inflorescence and flowers:
Usually helicoid cyme arising in the axil of foliage leaf or of a spathe like boat shaped bract.
Flowers usually bisexual, more or less irregular trimerous and hypogynous. Perianth is distinctly biseriate. The three outer tepals are sepal like herbaceous and green, often persistent and usually free or sometimes connate below. The inner three are petal like, white or blue, macrescent equal or unequal free or rarely united into a slender tube (Cyanotis)
Androecium: Basically six stamens in two alternate and trimerous whorls opposite the perianth segments. The filaments are usually free and often dissimilar.
Gynoecium: is tricarpellary and syncarpous with a superior and trilocular ovary. Style is one and stigma is capitate or threefid.
Fruit is usually loculicidal capsule.
Seeds are mostly muricate, ridged or reticulate.
Bright petals of the flower favors insect pollination.
Fruits are distributed by animals and birds.
Examples:
Commelina Cyanotis Pollia Murdania Floscopa Tonningia Belosynapsis

COMBRETACEAE

Anogeissus latifolia


Terminalia arjuna (अर्जुन)

Terminalia tomentosa (ऐन)

Anogeissus sericea (धावडा)

Combretum albidum (पीलूकी)


Combretum albidum (पीलूकी)

In India there are about 8 genera and 44 species occurring in most parts chiefly in Assam.

Vegetative characters:

Trees or shrubs, often climbing. Some of the climbers are twinning and others climb with the help of the hooks which are persistent bases of the petioles. The plants are usually rich in tannin.

The leaves are alternate or rarely subopposite or opposite,simple or rarely trifoliate as in Illigera and exstipulate.

Inflorescence and flowers:

The flowers are usually sessile and are born in racemose inflorescences which are often panicled.

The flowers are bisexual or rarely unisexual , actinomorphic, usually pentamerous and epigynous.

The calyx is typically of five sepals which are united to form a tube. The corolla is of five petals alternating with sepals. Sometimes the petals are absent in Terminalia and Anogeissus.The stamens are twice as many as petals ,in two alternate whorls. The filaments are inflexed in buds. The anthers are versatile, dithecous. The gynoecium has inferior ovary which is unilocular with two to six anatropous ovules. The style is one with a simple stigma.

A nectariferous disc is present on the summit of the ovary.

Fruits and seeds:

The fruit is dry or mdrupaceous, generally indehiscent, angular or more often winged.

The seed is one and without endosperm.

Pollination and Seed dispersal

Pollination is by insects visiting for nectar. In combretum by humming birds and even butterflies.

The fruits are dispersed by water and by wind.

Examples:

Terminalia. An exclusively tropical genus and about a dozen species occur in India.

Terminalia catappa (Indian almond) is largely cultivated in India for its edible nuts.

Many species such as T.alata(syn.T.tomentosa)T.panniculata,T.bialata, T. catappa and T. myricarpa provide valuable timber largely useful in construction work.

Fruits of many Terminalia such as T.bellerica T. arjuna ,T.glabra have medicinal values and figure in international commerce.

Quisqualis indica L.(Rangoon creeper) cultivated for ornamental purposes throughout India.