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Monday 29 December 2008

FAMILY OF THE WEEK: RUTACEAE


Murraya koenigii (Kadhilimb)


Murraya koenigii (Kadhilimb)


Murraya panniculata (Kunti)


Feronia limoni (Wood apple)

FAMILY OF THE WEEK: RUTACEAE

CITRUS FAMILY

Widely distributed in tropical and temperate regions especially in south Africa and Australia. In India it is rep[resented by 23 genera and over 80 species mostly in Himalayas and western Peninsular India.

Vegetative characters:

They are trees shrubs or rarely herbs. A characteristic feature of the family is the presence of pellucid glands filled with essential oils. The plants have spines as in Citrus and Aegle. The leaves are opposite or alternate and simple or compound. The stipules are absent. The leaves are mostly gland dotted.

Inflorescence and flowers:

The flowers are usually born in axillary or terminal cymes or panicles., sometimes they form racemes or they are axillary solitary or fascicled. The flowers are bracteate as well as bracteolate, usually hermaphrodite or sometimes unisexual and polygamous as in Zanthoxyllum, actinomorphic or sometimes zygomorphic as in Dictamnus, pentamerous, and hypogynous. A fleshy nectariferous disc is present between the stamens and the ovary.

The calyx is of four or fivr sepals which are free or more often show various degrees of connation. The corolla is composed of four or five free petals, which are valvate or imbricate in bud. The stamens are as many as or twice the petals or sometimes they are numerous as in Aegle and Citrus. The filaments are usually free. The anthers are dithecous, introrse and dehiscing longitudinally. The gynoecium is of two to five carpels which are completely united or sometimes the carpels are free towards the base and the ovary is deeply lobed. The styles are as many as carpels, free or variously united. The stigmas are terminal, entire or lobed.

Fruits and the seeds:

The fruit is a capsule or of free membranous ventrally dehiscing few seeded carpels or a drupe or a berry. The seeds may or may not contain endosperm and the embryo is straight or curvrd.

Pollination and dispersal:

The Rutaceae are adapted for insect pollination. The seeds are largely dispersed by animals and also by human agency.

Examples:

Citrus limon (Lemon)

Citrus medica (Citron)

Citrus aurantifolia (Bitter orange)

Citrus sinensis (Sweet orange)

Citrus reticulata (Loose skinned orange, Santra)

Citrus paradise (Grape fruit)

Citrus maxima( Chakotra)

Aegle marmelose (Bael)

Feronia limoni (Wood apple)

Feronia elephantum (Kavath)

Zanthoxylum

Murraya koenigii (Kadhilimb)

Murraya panniculata (Kunti)

Tuesday 23 December 2008

FAMILY OF THE WEEK: RUBIACEAE


Ixora


Anthocephalus cadamba

Anthocephalus cadamba


Mussaenda

Pavetta

FAMILY OF THE WEEK: RUBIACEAE

Rubiaceae is a large family. In India there are about 76 genera and 274 species occurring chiefly in the tropical and subtropical Eastern Himalayas extending up to 4600 meters and mountains of southern and Western India.

Vegetative characters:

The habit is chiefly woody and the family consists of mostly trees and shrubs.

The leaves are opposite decussate or sometimes whorled, simple entire and stipulate. The stipules show much variation in the form. They are frequently interpetiolar or intra petiolar. The stipules are often united. Sometimes as in Gardenia the four stipules are united into a conical cap which is thrown off as the bud opens. The bases of stipules are often glandular.

Inflorescence and flowers:

The inflorescence is basically a dichasial cyme and sometimes the small flowered cymes are aggregated into dense head as in Anthocephalus and Adina. In Morinda even the ovaries of the flowers in the head become fused. Rarely the flowers are solitary as in Gardenia and in Coffee one to three flowers stand in the axil of a leaf.

The flowers are actinomorphic or rarely slightly zygomorphic, bisexual tetra or pentamerous and epigynous.

The calyx is four or five lobed and the lobes are valvate. Sometimes as in Mussaenda one of the sepals in one or more flowers of an inflorescence becomes brightly coloured. The corolla is four or five fused petals and is salverform, rotate or funneliform. The petal lobes are valvate, twisted or imbricate in bud. The stamens are as many as the number of petals and they alternate with them. The anthers are dithecous introrse and opening lengthwise. The gynoecium is usually bicarpellary and syncarpous. The ovary is inferior and bilocular with axile placentation. The style is simple and the stigma is capitates or bilobed.

Fruits and the seeds:

The fruit is usually a septicidal or loculicidal capsule. Sometimes it is a berry(Coffee) or schizocarpic, separating into one seeded segments (Galium)

Pollination and dispersal:

The pollination is brought about by insects. Sticky fruits and persistent calyx limbs often favour their distribution by birds and animals. Sometimes the seeds are winged and are dispersed by wind.

Examples:

Coffee

Cinchona

Ixora coccinea

Gardenia

Mussaenda

Anthocaphalus cadamba (Kadamb)

Mitragyna parviflora (Kalam, Laghukadamb )

Adina cordifolia

Randia spinosa

Morinda

Pavetta crassicaulis

Tuesday 16 December 2008

FAMILY OF THE WEEK: ROSACEAE


Sorbaria tomentosa





Potentilla atrosanguina


Rosa webbiana


Spiraea canescens


Potentilla eriocarpa


Sibbaldia purpurea


Pear


Wild strawberry


Wild rose

FAMILY OF THE WEEK: ROSACEAE

There are over 25 genera and around 215 species in India mainly confined to temperate Himalayas ascending up to 6000 meters.

Vegetative characters:

The plants are herbs, shrubs or trees several species of Rose and Rubus have prickles. Sometimes, as in Prinsepia and Crataegus the shrubs are armed with sharp spines which are modified branches. Vegetative reproduction takes place in several ways.

The leaves are alternate and simple, pinnately or palmately compound. The stipules are usually present.

Inflorescence and flowers:

The flowers are rarely solitary or fascicled, but commonly they are arranged in various types of definite or indefinite inflorescences. The flowers are actinomorphic or sometimes strongly zygomorphic, bisexual or unisexual,polygamous, pentamerous, hypogynous, peri or epigynous. The calyx is of typically five basally connate sepals; the calyx tube is free or adnate to the ovary. The aestivation is imbricate or valvate. In some genera an epicalyx is also present. The corolla is of generally five free petals (there are numerous petals in cultivated species of Rosa) which are usually imbricate in bud. The number of stamens is variable from one to many. They are often in whorls. The filaments are distinct or sometimes monoadelphous. The anthers are dithecous and introrse. A cushion shaped or ringlike nectar secreting disc is present between the stamens and carpel. The gynoecium shows much variation. There are ten different tribes of gynoecial characters and type of fruits.

Seeds:

The seeds are usually without endosperm.

Pollination and dispersal:

In most Rosaceae the nectar is collected in the receptacular tube and easily licked by insects. The flowers are mostly protogynous and favour cross pollination.

The seeds are dispersed by animals and birds.

Examples:

Rosa multiflora (Rose)

Rosa damascene

Rosa indica

Rosa banksiae

Rosa centifolia

Pyrus mallus (Apple)

Pyrus communis (Pear)

Prunus persica (Peach)

Prunus domestica

Prunus institia (Plum)

Prunus armeniaca (Apricot)

Prunus amygdalous (Almond)

Fragaria chiloensis (Garden Strawberry)

Fragaria vesca L. (Alpine strawberry)

Spiraea

potentilla

Brambles

Cinquefoil

Monday 8 December 2008

FAMILY OF THE WEEK: RANUNCULACEAE




Clematis

FAMILY OF THE WEEK: RANUNCULACEAE

(BUTTERCUP FAMILY)

In India there are 20 genera and 154 species mostly confined to mountainous region.

Vegetative characters:

They are mainly annual or perennial herbs but some are climbers such as Clematis. Some are aquatic herbs. The perennial species usually develop rhizomes and tuberous roots. The vascular bundles in the stem of some genera are not arranged in a ring but are somewhat irregular, recalling the arrangement of monocots.

The leaves are radical or alternate or opposite as in Clematis. Stipules are absent but they often have sheathing bases. Generally they are simple and palmately lobed or divided but they are entire in Caltha, pinnately compound in Clematis and decompounds in Thalicrtum. Aquatic species show heterophylly with submerged leaves finely dissected.

Inflorescence and flowers:

The Inflorescence is variable. Most of the genera show typically determinate Inflorescence. The flowers are solitary terminal in Anemone and Nigella. They form long racemes in Delphinium and Acotinum and much branched panicles in Clematis and Thalictrum. The flowers are generally bisexual, mostly actinomorphic. The flower parts are arranged spirally on an elongated receptacle. The sepals are 5-8, distinct, imbricate or valvate, usually deciduous. The petals are usually five free symmetrical or irregular. The stamens are many polyandrous and spirally arranged. The anthers are adnate dithecous, extrorse and dehiscing longitudinally. The gynoecium is usually of numerous free carpels arranged spirally on a distinct thalamus. The style and stigma are one.

Fruits and seeds:

The fruit is usually a group of few to many seeded follicles or a group of one seeded achenes. In Clematis the achenes have long persistent feathery styles. The seed has a copious endosperm and a minute straight embryo.

Pollination and dispersal:

The flowers are protandrous and are adapted for insect pollination. The dispersal is by wind in many species. Some are disseminated by animals and birds.

Examples:

Ranunculus (Buttercup)

Thalictrum (Meadow- rue)

Clematis ( Virgins- bower)

Anemone (Wind flower)

Delphinium (Larkspur)

Acotinum (Aconite)

Aquilegia (Columbine)

Nigella (Love-in-a-mist)

Nigella sativa (Black fennel,Kala jeera)

Caltha (Marsh Marigold)

Paeonia (Peony)

Adonis aestivalis

Monday 1 December 2008

FAMILY OF THE WEEK: POLYGONACEAE


Antigonon leptopus


Polygonum auriculata


Polygonum auriculata





FAMILY OF THE WEEK: POLYGONACEAE

In India the family is represented by 8 genera and 110 species occurring chiefly in Himalayas.

Vegetative characters:

Mostly herbs but few are shrubby or trees. Sometimes they are climbers such as Antigonon which climb with the help of tendrils terminating the racemes.

The stems are often with swollen nodes and in Cocoloba platyclada the stems and branches are flattened to form phylloclades. The epidermis often forms red pigment. The leaves are alternate, rarely opposite or whorled, simple and entire, toothed or lobed as in Rheum. The leaves are stipulate and the stipules are characteristic of the family. They are usually membranous and forming a complete sheath(ochrea) around the stem above the leaf base. Crystals of Calcium oxalate are often present in the epidermal cells.

Inflorescence and flowers:

The inflorescence is primarily a compound raceme whose branches are cymose. The flowers are small, bracteates, hermaphrodite, actinomorphic, cyclic or acyclic and hypogynous.

The calyx is of three to six, free or basally connate, often petalloid, white or red and persistent sepals which are often enlarged and membranous in fruit. The aestivation is imbricate. The petals are absent. The androecium is of 5-9 stamens. The filaments are free or united at the base. The anthers are dithecous and opening lengthwise.

An annular nectar secreting glandular disc is mostly present at the base of the ovary. Gynoecium is usually tricarpellary and syncarpous. The ovary is superior and unilocular. The style is two-four clefted. The stigmas are various.

Fruits and seeds:

The fruit is an angled achene usually enclosed in the calyx. The seeds have copious endosperm.

Pollination and seed dispersal:

The flowers are pollinated by wind or insects. The fruits are mostly distributed by wind as the persistent calyx forms a membranous wing. Sometimes they have wings which help distribution by birds or animals.

Examples:

Fagopyrum esculentum (Buckwheat,Kuttu)

Fagopyrum tataricum (Duckwheat)

Oxyria digyna

Rheum (Rhubarb)

Rumex acetosa (Garden sorrel)

Rumex acetosella (Sheep sorrel)

Polygonum (Knot weed)

Antigonon leptopus (Coral vine)

Saturday 22 November 2008

FAMILY OF THE WEEK:PEDALIACEAE






Sesamum mulayanum







Martynia annua

FAMILY OF THE WEEK:PEDALIACEAE

In India it is represented by three genera and seven species occurring chiefly in south India. Martyniaceae is considered as a separate family by some.

Vegetative characters:

Annual or perennial herbs or rarely shrubs. Sometimes as in Martynia, the roots are tuberous. The leaves are opposite, exstipulate, simple entire lobed or divided.

Inflorescence and flowers:

The flowers are usually axillary solitary or in simple cyme or terminal raceme as in Martynia. At the base of the flower stalk characteristic glands are present which metamorphosed flowers are.

The flowers are perfect bisexual zygomorphic and hypogynous. The calyx is of usually five more or less united or distinct sepals. The corolla is gamopetalous, tubular-ventricose, limb obscurely bilabiate, five imbricate lobes. The stamens are usually foue, didynamous and epipetalous on the corolla tube. The fifth posterior stamen is represented by a small staminode. In Martynia there are only two fertile stamens and the remaining three are reduced to staminodes. The anthers are dithecous, introrsr and dehiscing longitudinally.

The gynoecium is bicarpellary and syncarpous with a superior ovary. The style is one and slender and the stigma is bilobed. A nectar secretins disc is present at the base of the ovary.

Fruits and the seeds:

The fruit is an indehiscent or dehiscent capsule often with a woody endocarp which is often horned or prickly. In Martynia the fruit bears two long curved horns.

Pollination and dispersal:

The flowers are often protandrous and are pollinated by insects which visit them for nectar.

The fruits are adapted for dispersal by large mammals. The fruits are armed with adhesive spines or hooks.

Examples:

Sesamum indicum

Sesamum mulayanum

Sesamum laciniatum

Martynia annua

Pedalium murex

Thursday 20 November 2008

FAMILY OF THE WEEK : PAPAVERACEAE


Argemone mexicana




California poppy (USA)

California poppy (USA)

FAMILY OF THE WEEK : PAPAVERACEAE

In India this family has 5 genera and about 20 species mostly confined to the Himalayas.

Vegetative characters:

Mostly perennial herbs with a milky or coloured latex.

The leaves are radical or alternate, exstipulate, simple and entire or more often lobed or divided.

Inflorescence and flowers:

The flowers are solitary at the end of main or lateral branches. Sometimes racemes or panicles. The flower buds are often nodding due to more rapid growth of one side of flower stalk.

The flowers are large showy, complete, hermaphrodite, actinomorphic, di-or tri merous and hypogynous.

The sepals are two or three(Argemone), free or united, imbricate and caduceus.

The petals are four to six, biseriate, imbricate and often rolled or crumpled in bud.

The androecium consists of numerous free stamens in several whorls; the filaments are slender; and the anthers are erect, dithecous, extrorse and opening lengthwise.

The gynoecium is of two to many carpels, and it is syncarpousThe ovary is superior and unilocular. The style is very short or absent and the stigmas are as many as carpels, radiating connate and opposite or alternating the placenta.

Fruits and seeds:

The fruit is a many seeded capsule opening by pores or by valves under the lobes of persistent stigmas. The seeds are small with a minute embryo and a copious fleshy fleshy or oily endosperm.

Pollination and seed dispersal:

Self and cross pollination.Flowers do not contain nectar and are visited by pollen seeking insects. The seeds are usually dispersed by wind or by birds, animals or human beings. The seeds of Papaver and Argemone are dispersed by adhesion to animals, carts or feet of humans.

Examples:

Papaver somniferum L: Opium poppy

Papaver rhoeas (Corn poppy)

Papaver nudicaule (Iceland poppy)

Papaver orientale (Oriental poppy)

Argemone mexicana

Tuesday 18 November 2008

ORCHIDACEAE


Habenaria marginata

Aerides maculosum

Zeuxine strateumatica










FAMILY OF THE WEEK: ORCHIDACEAE

A large family of 735 genera and over 17000 species, cosmopolitan in distribution but abundant in tropics and rare in arctic regions. This is the second largest family of the Indian flora, with 128 genera and about 881 speciesoccuring in Himalayas western ghats.They are most abundant in eastern Himalayas.

Vegetative characters:

Perennial herbs, terrestrial, epiphytic or saprophytic. The tropical species are mostly epiphytes while those occurring in temperate zones are largely terrestrial.

They have fleshy roots, root stocks corms or bulbs.

Terrestrial forms are sympodial. The internodes are often swollen to store food.

The epiphytic forms are mostly sympodial or sometimes monopodial. They develop aerial roots which have an outer layer of water absorbing tissue, the velamen. Most epiphytic forma drop their leaves in dry season. They usually develop a fleshy pseudo –bulb every year. The saprophytic form don’t have green leaves and they grow on humus.

The leaves are alternate often distichous or rarely opposite. The leaves are often fleshy linear or ovate. They are sheathing at base and encircling the stem.

Inflorescence and flowers:

They are solitary or in racemes spikes or in panicles.

The flowers are often showy and beautifully coloured. They are bracteates, bisexual or rarely unisexual zygomorphic and epigynous. The perianth is in two trimerous whorls, the outer often calyx like and inner corolla like. The tepals are free or variously connate in each whorl. Outer tepals are alike. The two lateral tepals of the inner whorl are alike but the median tepal is very different in size, shape and the colour from the lateral tepals. It is bulbous,spurred,tubular,strap shaped or variously divided and contribute to the beauty of the flower. This modified tepal is called lip or labellum.

The most characteristic pattern of the orchid flower is gynandrium or coloumn which is a highly complex structure formed by the adnation of the stamens style and the stigma.

The androecium is usually represented by one or two sessile anthers.

The gynoecium is tricarpellary and syncarpouswith an inferior ovary.

Fruits and seeds:

The fruit is usually a capsule opening laterally by three to six hygroscopically sensitive valves. The seeds are large in number minute often fusiform and rarely winged.

Pollination and seed dispersal:

The flowers are adpted for insect pollination.The innumerable light seeds are suited to distribution by wind.

Examples:

Cypripedium

Catteleya

Habenaria

Vanda

Cymbidium

Dendrobium

Epidendrum

Orchis

Aeridis

Vanilla planifolia

Saturday 8 November 2008

OXALIDACEAE





Oxalis dehradunensis

FAMILY OF THE WEEK : OXALIDACEAE
The OXALIDACEAE contains 3 genera and 875 species mostly in tropical and subtropical region.In India there are 2 genera and about 12 species distributed mostly in Himalayas. Indian sorrel is a common example found throughout India.
Vegetative characters :
Perennial herbs. Plants often produce fleshy rhizomes or bulbous tubers. The leaves are alternate or radical(Oxalis), digitately (Oxalis) or pinnately(Biophytum) compound and exstipulate.
The leaflets are folded and bent downwards in bud at night. The leaves of many species of Biophytum are sensitive and the leaflets bend down when touched.
Inflorescence and flowers :
The flowers are solitary or subumbellate or racemose.They are bracteate, complete and hermaphrodite, actinomorphic, pentamerous and hypogynous. The calyx is of five imbricate and persistent sepals which are free or united. The corolla is composed of five shortly clawed, free or basally connate petals. The androecium is of 10 stamens in alternate whorls.They are obdiplostemonous. The filaments are connate at the base. The gynoecium is pentacarpellary and syncarpous with a superior five-locular ovary. The styles are five, free and persistent and the stigmas are capitate or shortly divided.
Fruits and seeds :
The fruit is loculicidal capsule. The seeds have a straight embryo enveloped by a fleshy copious endosperm. An explosive aril is often present on the seeds.
Pollination and seed dispersal :
The flowers are protandrous and the pollination is by insects. The seeds are shot off as the capsule opens.
Examples :
Oxalis corniculata
Oxalis pes-caprae,

Oxalis corymbosa
Oxalis latifolia
Oxalis dehradunensis
Biophytum sensitivum