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Thursday 31 January 2008

Apocynaceae





Apocynaceae : Oleander family or dogbane family.
Around 60 species in India.
Vegetative characters:
Herbs : e.g.Lochnera
Shrubs :e.g. Nerium
Trees : Alstonia
Climbers : Vallaris
or even
Lianas :Landolphia
Sometimes stems are armed with sharp spines as in Carissa.
Latex is present in unsegmented tubes and the vascular bundles are bicollateral.
Leaves are usually opposite decussate ;sometimes whorled or scattered (Plumeria).They are simple entire without stipules.
Flowers arranged in axillary or terminal cymose or panicled inflorescences ;rarely solitary.
They are bracteate, bisexual,perfect,actinomorphic,pentamerous and hypogynous.
Calyx is gamosepalous- 5 lobed.Corolla isgamopetalous 5 lobed salver shaped but sometimes campanulate/bell or funnel shaped. Stamens are distinct and as many as corolla lobes and alternate with them and adnate to the corolla tube.Filaments are short.Anthers introrse and adherent to the stigma.Gynoecium-usually bicarpellary with superior ovary ar rarely partly inferior ovary(Plumeria).When distinct each ovary is unilocular with ventral placenta.Stigma is massive variable in shape and often bilobed.
A hypogynous nectariferous disc is present which is annular,cup shaped,lobed or of distinct glands.Fruit is of two follicles dehiscing by ventral suture,sometimes berry or capsule.
Seeds are flat often winged or with a tuft of hairs at one end.
Pollination and seed dispersal:Flower is adapted for insect pollination
Apocynum :for insect pollination.
Nerium :adapted for long tongued lepidoptera.
Vinca : When insect enters its proboscis into the corolla tube it is smeared with adhesive matter and when withdrawn,it is cemented with pollens.
Winged seeds and hairs favour distribution by wind.
Economic importance and uses:
Members of the family provide a large number of ornamentals and some useful drugs.
Vinca rosea(Catharanthus roseus:Periwinkle,Sadafuli)An everblooming perennial herb with rosy purple flowers.Some anticancer drugs are extracted from it.
Thevetia peruviana:Yellow oleander,Peeli Kaner.Leafy evergreen shrub with yellow to orange flowers widely planted in gardens.Uses in rheumatism and dropsy.
Nerium indicum(Kanher)Ornamental shrub with white to pink red flowers again widely planted in gardens.
Plumeria(Frangipani,white champa,Chapha):A common garden plant with Fragrant flowers in different colours.
Tabernaemontana divaricata(Crape jasmine,Chandani:Syn.Ervatamia coromaria)white waxy flowers:common garden plant.
Carissa congesta :(Syn.C.carandas,Karaunda,Karawand.)Sweet edible fruits, widely found shrub of Sahyadris.
Rauvolfia serpentina(Sarpagandha)Found in tropical Himalayas also widely cultivated.Digitalis a common medicine for heart is procured from it.
Holarrhena antidysenterca:(Kutaj or Kuda)As the name suggests:Extract from root and bark is used in dysentery.
Wrightia tinctoria: Leaves are the source of a blue dye Indigo. Alstonia scholaris:An evergreen tree with dense crown,often planted in gardens and as avenue tree.Wood is used in packing and the bark has medicinal value.

Friday 25 January 2008

Annonaceae



Though I would have liked to discuss about related families every week, Some theme has to be selected that is the reason why I am going alphabetically. It may look little odd as the families in consecutive weeks may not have any relation with each other.





This week's family is

Annonaceae
Widely distributed in tropics.Common examples are Annona squamosa,Polyalthia longifolia and Artobotrys odoratissimus.
Vegetative characters:Usually aromatic trees or shrubs,or sometimes woody climbers.
The leaves are alternate exstipulete,simple and entire.Oil passages are present in stems as well as leaves.
The flowers are often solitary,axillary terminal or leaf opposed or sometimes fascicled.
The flowers are mostly bisexual actinomorphic and hypogynous.
The perianth is usually trimerous and differentiated into calyx and corolla.There are three sepals and usually six petals in two whorls.Androecium has numerous stamens spirally arranged on alrge convex receptacle
and the gynoecium has one to indefinite carpels which are spirally arranged on the receptacle above the stamens.The carpels are free but very rarely,as in Annona, they are subconnate with distinct stigmas. The ovary is superior,unilocular with usually many anatropous ovules in two rows on the ventral suture of the carpel.
The fruit is often an aggregrate of berries.Many seeded berries are usually constricted between the individual seeds.In annona the berries become confluent with each other and with the receptacle to form a globose or ovoid many seeded freshy fruit.The seeds are large with a small embryo.
Flowers are often fragrant due to oil sacs and are pollinated by flies.
In most Annonaceae the mature carpels are juicy and coloured and are freely eaten by birds and bats.Annona which has compact fleshy fruit, too big to be carried by birds is generally dispersed by mammals.Th seeds of Artabotrys and polyalthia are drifted by sea.
Examples:
Many species yield edible fruits: Annona squamosa(Custard apple),A.reticulata(Common
Custard apple),Canaga odorata.
Some species are grown as ornamentals:
Artabotrys odoratissimus(Climbing Ylang Ylang)
Polyalthis longifolia and pendula(Ashoka)One of the most beautiful avenue trees.
Flowers of Canaga odorata and
Artabotrys odoratissimus yield an essential oil which is used in high class perfumery and toilet preparations.
The leaves of trees of Annonaceae are larval host plants of Tailed jay butterflies so these butterflies are abundant in gardens with these trees.

Thursday 17 January 2008

Amaryllidaceae

Most of the discussions on indiantreepix and wildflowerindia are about description of plants and its identification by members who may or may not be conventional botanist.
For identification of a plant basic scheme of classification must be known.
All seed producing plants are divided into
Gymnosperms(naked seeds)and Angiosperms(Seeds covered in fruit).
Angiosperms
or the flowering plants is the major group with its members visible to most of us daily such as garden plants and vegetables and fruits which we eat.
Angiosperms or flowering plants are further divided into two groups
Monocotyledons and Dicotyledons.
This week's family is from Monocots.

Amaryllidaceae

Vegetative characters:Perennial, bulbous, tuberous or rhizomatous herbs of usually xerophytic habit.Leaves are usually linear and in basal rosettes.
Flowers
are born at the top of the scape which is usually naked.They are solitary or in two to many flowered umbels, Subtended by an involucre of two or more bracts.Flowers are often large showy, bisexual, actinomorphic or sometimes zygomorphic, trimerous and epigynous.The perianth is of six tepals in two trimerous whorls.Tepals are free or united into a tube as in Narcissus.
Six stamens in two alternate whorls of three each.Filaments are free or form a staminal cup in Eucharis,Hymenocallis and pancratium.
Gynoecium is tricarpellary and syncarpous.Ovary is inferior and trilocular.
Fruit is a capsule dehiscing loculicidally or irregularly or rarely it is a fleshy berry.
Pollination and dispersal:Flowers are showy bright and often fragrant.The nectar secreted by the septal nectaries collects at the bottom of the flowers.Thus they are adapted for insect pollination.The white and sweet scented flowers of Crinum arepollinated by butterflies and honeysucking birds.
Narcissus is chiefly pollinated by nocturnal lepidoptera.
The seeds of some spcies of Crinum have a thin corky covering and are suited for distribution by water.
The family provides a large number of beautiful ornamental plants.
The notable are:

Amaryllis belladonna.
Narcissus.
Crinum.
Zephyranthes.
Polianthes tuberosa.
Euchalis grandiflora(Amazon Lily)
Hymenocalis americana(Spider Lily)
Pancratium maritimum
Agave:often grown for fencing and yields valuable fibre for ropes carpets etc.

Thursday 10 January 2008

Amaranthaceae









Out of the 315 odd families some 50to 60 are commoner and more important.
This week's family is

Amaranthaceae.Cockscomb family.
Greek amarantos : unfading....long lasting flowers.

India and tropical America are chief distribution centres.
Large family--Includes some garden plants and pot herbs.
Vegetative characters :annual or perennial herbs,shrubs and rarely erect or climbing shrubs.
Stems often show abnormal secondary growth.
Leaves:alternate or opposite exstipulate,simple usually entire.
Flowers and Inflorescences:Small flowers are aggregated into simple or branched panicles spike s heads or cymes.Flowers are actinomorphic,bisexual or frequently unisexual,pentamerous and hypogynous.
Calyx-5 free basally connate sepals.
Petals are absent.Stamens are 5 and areopposite the sepals.
Sometimes nectar secreting disc is present.(bosia)
Pollination and dispersal:Nectar disc and showy flowers ==>insectpollination
Gomphrena--winged fruits=>dispersal by wind.Achyranthus Cyathula and Pupalia develop hooks on sepals which adhere to passing animals and humans.
Economic Importance:Little.
Few are used as food.
Examples:
Amaranthus (Mar.Chavalai)Leafy vegetable.
Celosia argentea:spikes attract butterflies,Tender shoots are cooked and eaten
Alternanthera tenella and A.sessilis are common weeds.
Gomphrena globosa.
Achyranthus aspera (Aghada)

Friday 4 January 2008

Acanthaceae










Justicia procumbens










Asystasia dalzelli

 








Asystasia gangetica










Asystasia intrusa












Hygrophila serpyllum


Hygrophilla schulii


Hemigraphis latebrosa


Cynarospermum asperrimum


Carvia callosa


Eranthemum roseum


Thunbergia grandiflora



Thunbergia alata

Carvia Nilgrianthes










Barleria

In the new year why not share some of the facts about families of plants.
For plant identification knowledge of families is very much important.
There are about 315 families of flowering plants.

ACANTHACEAE family

Acanthus:Greek akanthos =thorn=>often spiny leaves /bracts
Mostly in the tropical parts of the world .some extending into temperate regions.
Vegetative characters :annual or perennial herbs,shrubs or climbers.
Leaves opposite decussate simple and entire and rarely divided.
Flowers:most common dichasial cyme.Sometimes axillary solitary(Thunbergia)
Flowers are often well developed and coloured.Bilipped corolla.
Examples:
Barleria(Koranti in Marathi)cultivated as ornamental hedge plant in gardens
Adhatoda vasica (Adulsa: a common cough cure)
Thunbergia:climber commonly planted on hedges and walls as decorative
Justicia
Carvia callosa:flowers every 7-8 years
Ruellia