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.

CASUARINACEAE

Casuarina equisetifolia

A small family of two genera and 65 species confined to the southern hemisphere from South East Asia to northeast Australia. In India the family is represented by single genus and single species which occurs on east side of Bay of Bengal from Chittagong southwards and also cultivated in several parts of India.

Horse-tail tree (Casuarina equisetifolia) is the familiar example of the family.

Vegetative characters:

They are much branched evergreen trees or shrubs of xerophytic habit with long or short, green , cylindrical and striate, whorled and jointed branches. The internodes of branches are furrowed. The leaves are in whorls of four to sixteen depending upon the species. They are small scale like linear lanceolate and are always basally connate forming a sheath surrounding the node.

Inflorescence and flowers:

The flowers are unisexual and the trees are monoecious or dioecious.

The male flowers are born in catkin like spikes which are terminal at the end of the green branchlets. At each of node of the Inflorescence axis there are several flowers protected by a sheath formed of the combined bracts. The stamens hang out over the edge of the sheath.

The female flowers are crowded in dense spherical or ovoid heads at the ends of the short lateral branches. The perianth is absent and the flowers are naked. The gynoecium is bicarpellary and syncarpous with a superior ovary.

Fruits and seeds:

The fruit is a samaroid indehiscent nut enclosed by persistent woody bracteoles which separate on maturity. The fruits are aggregated into a dry woody cone- like multiple fruit. The seeds are nonendospermic with straight embryo and flat cotyledons.

Pollination is by wind. Seed dispersal of Casuarina equisetifolia is by sea.

Economic importance:

The wood of several species of Casuarina is valued for hardness. The wood of Casuarina equisetifolia is known as ironwood. Some species are grown for ornament.

CARYOPHYLLACEAE

CARYOPHYLLACEAE

In India this family consists of 20 genera and 105 species mostly in temperate regions.

Vegetative characters:

Mostly annual or perennial herbs and rarely under shrubs . Stellaria aquatica is an aquatic herb.

The root is usually a tap root and the stem is often swollen at nodes.

The leaves are opposite or rarely alternate, simple, mostly linear to lanceolate and sessile. The two leaves at the stem are often connected basally around the stem. The stipules are usually absent.

Inflorescence and flowers:

The Inflorescence is typically dichasial cyme often terminating the main axis. A branch is formed in the axil of each bracteole of the main axis but one of the branches tends to outgrow the other and in the ultimate branching the weaker branch fails to develop. Thus the Inflorescence which is dichasial cyme in its initial branching pass into scorpioid cyme. This type of Inflorescence is very characteristic of the family and is known as cincinnus or caryophyllus type of Inflorescence.

The flowers are hermaphrodite or rarely unisexual, actinomorphic, pentamerous and hypogynous or rarely slightly perigynous as in arenaria.

The calyx is usually five basally connate sepals .

The corolla has as many petals as the sepals. The petals are free and are usually differentiated into a limb and a claw. The stamens are usually twice the number of petals in two equal and alternate whorls. They show obdiplostemonous condition. The filaments are distinct or slightly connate at the base.

The gynoecium is of two or three to five fused carpels.the ovary is superior or slightly inferior and unilocular with free central placentation.

A disc is present at the base of the stamens which is annular or divided into glands.

The fruit is membranous or crustaceous capsule opening by valves or apical teeth.

The seeds are endospermic with more or less curved embryo.

Pollination is by insects.

The seeds are dispersed by water, wind or by adhesion or by birds, animals and human agency.

Examples:

The family is valuable for its large colourful ornamental flowers which are easily grown.

Dianthus species are cultivated for very showy flowers.

Dianthus caryophylus. (Carnation)

Dianthus plumarius

Dianthus latifolius

Dianthus barbatus

Vaccaria pyramidata

Silene

Lychnis

Gypsofila

Cerastium

Arenaria

Stellaria media; S.vestita

Spergula arvensis

CAPPARIDACEAE

Capparis grandis

Cadaba fruiticosa

Capparis decidua(aphylla)


Crataeva nurvala


Maerua oblongifolia

CAPPARIDACEAE OR CAPER FAMILY
In India 7 genera and 53 species occuring in western and south India and few in tropical Himalayas.
Vegetative characters:
The family includes herbs shrubs and climbers.They contain watery sap.
The leaves are alternate and simple(Capparis) or more commonly palmately compound(3-9 foliolate).The stipules are usually present which may be foliaceous(Cleome) or spinose(Capparis).
Inflorescence and flowers : The flowers are solitary and in fascicles of 3 or4 but more commonly the are racemose.
The flowers are bracteate,complete, usually bisexual actinomorphic or some what zygomorphic by unequal development of members as in Capparis, tetramerous and hypogynous.
The calyx is usually of four sepals which are free or basally connate with valvate or imbricate aestivation.The four sepals are arranged in two series. The posterior sepal forms a hood like structure in Capparis.
The corolla is of four free petals but occasionally the are two(Cadaba) or altogether absent(Roydsia).The petals are diagonal,often clawed and valvate or imbricate.They are inserted on the edge of a disc in Maerua.
The androecium is of four to numerous free stamens.An androphore is present in some species of Cleome.
The gynoecium is usually bicarpellary and syncarpous; the ovary is sessile or elevated on a short or long gynophore, unilocular with two or four parietal placentae. The style is usually short with a bilobed or a capitate stigma.
The fruit is a capsule dehiscing by two valves(Cleome) or a berry(Capparis) or drupaceous. The seeds are angled or reniform, nonendospermic and with an incurved embryo.
Pollination and dispersal : The pollination is by insects which visit flowers for nectar secreted by the disc.The fruits are dispersed by water current(Crataeva) or by cattle by adhesion due to viscid exudation.
Examples :
Capparis
Cleome gynandra
Crataeva nurvala
C. religiosa
Maerua oblongifolia
Cadaba fruiticosa