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Friday, 30 January 2009

FAMILY OF THE WEEK: SOLANACEAE





FAMILY OF THE WEEK: SOLANACEAE (NIGHTSHADE FAMILY)
A large family with over 2000 species worldwide. In India there are 15 genera and 88 species. Many species are cultivated while others occur chiefly in Himalayas and southern and eastern parts of India.
Vegetative characters:
They are mostly annual or perennial herbs, sometimes shrubs or small trees and rarely climbers. The stems are prickly or spinous, the spines are modified branches. The vascular bundles are bicollateral. Underground tubers are found in Solanum tuberosum. The leaves are alternate,exstipulate, simple,entire, lobed or pinnatified. In the inflorescence portion the leaves often become subopposite or opposite.
Inflorescence and flowers:
Often cymes which are lateral, axillary or terminal. In some species of Solanum they are extraaxillary appearing to arise from the middle of an internode. Very frequently they are solitary and axillary as in Datura and Nicardia and rarely clustered as in Withania. The bracts and bracteoles are absent.
The flowers are actinomorphic or sometimes zygomorphic, bisexual, pentamerous and hypogynous. The calyx is five lobed or five partite and usually persistent and much enlarged in fruit. The corolla is gamopetalous and funnell shaped(Datura) campanuloate(Physalis) or rotate(Solanum) The limb is usually five lobed or rarely ten lobed as in Datura and the lobes are folded contorted or valvate. The stamens are usually five,epipetalous on the corolla tube and alternate with the lobes. They are commonly of unequal heights. The anthers are ovate or oblong, sometimes connivant into a cone as in Solanum, dithecous,introrse and dehiscing by longitudinal slits or by apical pores.(Solanum)
Thhe gynoecium is typically bicarpellary and syncarpous. The ovary is superior and bilocular with axile placentation.The style is linear and the stigma is capitate or shortly lobed.
A hypogynous nectariferous disc is usually present at the base of the ovary.
Fruits and seeds:
The fruit is a berry which is sometimes (Physalis)enclosed within an inflated bladder-like calyx or capsule. The seeds are numerous, compressed, discoid or subreniform, endospermic and with a curved or straight embryo.
Pollination and dispersal:
Conspicuous flowers and nectariferous disc favor insect pollination. Solanum tuberosum is devoid of nectar and is scarcely visited by insects. Here usually self pollination occurs by the style curving backwards to touch the anthers.
The seeds are usually dispersed by birds and animals.Species of Datura,Atropa and Hyoscyamus are dispersed by water.
Examples:
Solanum tuberosum (Potato, Batata)
Solanum melongena (Egg plant,Brinjal,Baingan,Wang) Lycopersicon esculentum(Tomato)
Capsicum annuum
(Chillies, Mirch)
Nicotiana tobacum
(Tobacco)
Atropa belladonna
(Belladonna)
Hyoscymus niger
Datura stramonium
Withania somnifera
(Ashwagandha)
Withania coagulans (Indian rennett)
Petunia

Wednesday, 21 January 2009

FAMILY OF THE WEEK: SCROPHULARIACEAE


Rhamphicarpa

Verbascum chinens

Lindernia ciliata

FAMILY OF THE WEEK: SCROPHULARIACEAE
This family is cosmopolitan in distribution but most abundant intemperate regions. In India it is represented by 57 genera and 350 species occurring chiefly in Himalayas.
Vegetative characters:
Mostly annual or perennial herbs, sometimes shrubs (Veronica) or rarely trees(Wightia). Certain members are aquatic(Limnophila) or marsh (Departrium and Herpestis) Some are chlorophyll containing hemiparasites(Pedicularis and Striga) or parasites without chlorophyll as Lathraea.
Usually the lower leaves are opposite and upper alternate.They are simple exstipulate entire or pinnately lobed or incised.
Inflorescence and flowers:
Variable but commonly racemose or spicate. Sometimes cymose or axillary solitary.The bracts and bracteoles are usually present.
The flowers are perfect, hermaphrodite,zygomorphic or sometimes as in Verbascum nearly actinomorphic and hypogynous.The calyx is deeply five lobed or divided, persistent, imbricate or valvate. The corolla is gamopetalous and the limb is usually free and more or less bi-lipped.Commonly five stamens are fertile and the fifth is reduced to a staminode or is completely absent.The stamens are epipetalous. the anthers are dithecous but occasionally the two cells are unequal or only one cell is present. The gynoecium is bicarpellary and syncarpous with a superior bilocular ovary. The style is simple and the stigma is capitate, bilobed or bi-lamellate.
An annular or cup shaped nectariferous disc is present at the base of the ovary which is sometimes bilobed.
Fruits and seeds:
The fruit is a capsule or rarely a berry. the seeds are small with a fleshy endosperm and straight or slightly curved embryo.
Pollination and dispersal:
The flowers are adapted for insect pollination. The seeds are dispersed by water, birds or animals.
Examples:
Antirrhinum majus (Snapdragon)
Digitalis purpurea (Common foxglove)
Linaria vulgaris
Verbascum chinens
RhamphicarpaLobelia nicotianifolia(Ran Tambaku)Lindernia ciliata

Thursday, 15 January 2009

FAMILY OF THE WEEK: SAPOTACEAE





Achras sapota

Mimuseps elengi


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FAMILY OF THE WEEK: SAPOTACEAE
In India there are 10 genera and 52 species occurring mostly in North Eastern and Southern India.
Vegetative characters:
They are trees or shrubs with young parts often rusty tomentose. The plants contain a milky juice. The leaves are alternate or rarely subopposite, simple, entire,petioled and coriacious and leathery. The stipules are usually absent.
Inflorescence and flowers:
The flowers are solitary or in cymose clusters in the leaf axils. They are bisexual, actinomorphic and hypogynous. The calyx has four to eight sepals which are united at the base. They are arranged in two or one series. The corolla is gamopetalous but the corolla tube is shorter than the calyx tube. The corolla lobes are usually as many as the calyx lobes and alternate with them and sometimes twice as many as the calyx lobes. The petal lobes are imbricate in bud.
The stamens are inserted upon the corolla tube. They are usually as many as the corolla lobes and opposite to the corolla lobes. Sometimes the stamens are two to three times as many as the corolla lobes and then they are two or three seriate. The outer stamens are sometimes reduced to staminodes as in Mimusops. The filaments are usually short. The anthers are oblong lanceolate, dithecous and extrorse. The connective is often produced beyond the anthers. The gynoecium has two to eight syncarpous carpels. The ovary is superior with as many locules as the number of carpels. The style is one, often apically lobed.
Fruits and seeds:
The fruit is one to eight seeded berry. Latex sacs are also present in the inner pulp of the berry. The seeds are often compressed with a crustaceous testa. The embryo is straight.
Pollination and dispersal:
Pollination is by insects. Fruits are distributed by birds and animals and water currents.
Examples:
Achrus sapota (Sapodilla plum)
Manilkara hexandra
Madhuca indica
Mimuseps elengi (Bakul)

Friday, 9 January 2009

FAMILY OF THE WEEK: SAPINDACEAE


Schleichera oleosa (Kusam)


Sapindus


Sapindus

FAMILY OF THE WEEK: SAPINDACEAE ACERACEAE(MAPLE FAMILY)
Large family represented in India by 24 genera and 72 species occurring in the tropical eastern Himalayas and western peninsular India.
Vegetative characters:
The members of the family are trees or shrubs or sometimes vines. The stems show peculiar secondary growth in thickness.
The leaves are alternate or rarely opposite (Acer), usually pinnately compound, sometimes simple (Cardiospermum), palmately lobed and veined (Acer) or digitate (Aesculus). They are exstipulate but occasionally stipulate as in Melianthus. The latex or resin cells are often present in the leaves.
Inflorescence and flowers:
Racemose inflorescence with minute flowers or unilateral cymes in panicles. The flowers are mostly polygamo-dioecious. They are zygomorphic or occasionally actinomorphic, tetra or pentamerous and hypogynous.
The calyx is composed of four or five sepals which are free or variously connate, often unequal and valvate or imbricate in bud.
The corolla is of four to five free petals but usually there are four petals and the place of fifth petal is vacant.
The androecium has typically eight or ten stamens or sometimes less as in Aesculus.
An annular or unilateral disc is often present between the petals and the stamens.
The gynoecium is usually tricarpellary and syncarpous. The ovary is superior.
Fruits and the seeds:
The fruit is capsular or it is indehiscent and entire or lobed as in Sapindus. Sometimes the fruit is a double Samara as in Acer or nutlike as in Litchi.
The seeds are globose or compound, often arillate, endospermic or nonendospermic with often plicate or spirally convolute embryo.
Pollination and dispersal:
The flowers are often protandrous and pollinated by insects. Flies and humble bees are the chief pollinators.The fruits of Dodonia and Acer are blown to long distances by strong winds. The dispersal also takes place by birds and animals in many genera.
Examples:
Litchi chinensis
Sapindus mukorossi (Soapnut tree, Ritha)
Sapindus laurifolius Acer saccharinum (Sugar Maple)
Aesculus hippocastanum (Horse chestnut)
Schleichera oleosa (Kusam)
Dodonia viscose (Vilayati Mehandi)
Nephelium lappaceum (Rambutan)

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