Sunday, 20 April 2008
Bentham and Hooker divided the Leguminosae into three subfamilies : Papilionaceae,Caesalpinieae and mimoseae.Most of the recent taxonomist treat them as three distinct families.
CAESALPINIACEAE is a very big family, mostly tropical and subtropical trees and shrubs comprising about 150 genera and 2,200 species.In India 23 genera and 80 species chiefly in western peninsular india.
Mostly trees or shrubs or rarely herbs. Occasionally woody climbers.
The leaves are stipulate, alternate, and mostly pinnately compound but may be bipinnate or simple.The leaf base is often swollen.
Inflorescence is racemose or pannicle rarely cymose.
The flowers are mostly large and showy, zygomorphic,pentamerous, bisexual and hypogynous or perigynous.
The perianth commonly consists of a calyx and corolla of 5 segments each; the petals are distinct, overlapping (i.e., imbricate) in bud, with the posterior one (flag or banner) innermost in position.
In tamarindus and Amherstia only the Three upper petals are developed and the two lower are reduced to scales.The petals are altogether absent in Saracca.
The androecium usually consists of 1-10 distinct or variously united stamens, some of which are commonly reduced to nonfunctional staminodes.
The pistil is simple, consisting of one style and stigma, and a superior ovary with one locule containing 2-many marginal ovules.
The fruit is usually a legume.
The pollination is by insects or birds and the seed dispersal is by wind or by animals.
30-200 genara and around 200 species.
The family is almost restricted exclusively to the drier regions of north and south America and is most abundant in Mexico and central America.
Several species of Opuntias have been naturalised in India.
Vegetative characters :
The members of the family are mostly fleshy and succulent, and some grow upto 20 meters high.
The root system is generally small and shallow with elongated slender and fleshy roots.
Cactus stems are fleshy,peculiar and of various shapes. The leaves are alternate, generally extremely reduced and ephemeral or absent, or rarely they are well developed and fleshy. The leaves are associated with highly modified axillary buds or shoots called areoles that bear spines.
The inflorescence is a terminal or lateral panicle in Pereskia but in majority the flowers are solitary born upon or near the areole or on the axiles of tubercles.
The flowers are sessile often large bright coloured and showy, mostly bisexual and actinomorphic and commonly have many weakly differentiated perianth segments arising from an epigynous zone.
The androecium typically consists of a very large number of stamens arising from the inner face of the epigynous zone.
The gynoecium consists of a compound pistil of 3-many carpels, an equal number of stigmas, and an equal number of parietal placentae with numerous ovules in the single locule of the inferior ovary.
The fruit is a berry with numerous seeds, often with spines or bristles.
Large showy flowers are adapted for insect pollination.
Fruits are sweet in taste and are often distributed by animals.
Examples and Uses:
The fruits of several species of opuntias are edible.
Species of opuntias Nopalaea etc are used for hedges along the fields.
Cochineal dye is derived from the small insect living on the species of Opuntias and Nopalaea.
Timber is obtained from Pereskia.
Spineless opuntia is grown as fodder.
Because of their peculiar forms and gorgeous flowers several species of Mammilaria,Epiphyllum,Cereus,Echinocereus are grown in green houses.
Epiphyllum oxypetalum -ब्र्म्हकमळ
Friday, 11 April 2008
Two genera and more than 900 species: mainly in tropical and subtropical Africa, some species in temperate Asia, Europe, and North America; two genera and 228 species (187 endemic, two introduced) in China; three additional species (all endemic) are of uncertain placement.
All but one of the species in the family belong to Impatiens. The unispecific Hydrocera is confined to India and SE Asia.
Herbs annual or perennial [rarely epiphytic or subshrubs]
Stems erect or procumbent, usually succulent, often rooting at lower nodes.
Leaves simple, alternate, opposite, or verticillate, not stipulate, or sometimes with stipular glands at base of petiole, petiolate or sessile, pinnately veined, margin serrate to nearly entire, teeth often glandular-mucronate.
Flowers bisexual, protandrous, zygomorphic, resupinate to through 180° in axillary or subterminal racemes or pseudo-umbellate inflorescences, or not pedunculate, fascicled or solitary.
Sepals 3(or 5) ; lateral sepals free or connate, margins entire or serrate; lower sepal (lip) large, petaloid, usually navicular, funnelform, saccate, or cornute, tapering or abruptly constricted into a nectariferous spur broadly or narrowly filiform, straight, curved, incurved, or ± coiled, swollen at tip, or pointed, rarely 2-lobed, rarely without spur.
Petals 5, free, upper petal (standard) flat or cucullate, small or large, often crested abaxially, lateral petals free or united in pairs (wing).
Stamens 5, alternating with petals, connate or nearly so into a ring surrounding ovary and stigma, falling off in one piece before stigma ripens; filaments short, flat with a scalelike appendage inside; anthers 2-celled, connivent, opening by a slit or pore.
Gynoecium 4- or 5-carpellate, syncarpous; ovary superior, 4- or 5-loculed, each locule with 2 to many anatropous ovules; style 1, very short or ± absent; stigmas 1-5.
Fruit an indehiscent berry, or a 4- or 5-valved loculicidal fleshy capsule, usually dehiscing elastically. Seeds dispersed explosively from opening valves, without endosperm; testa smooth or tuberculate.
Examples: Different species of Impatiens.Terada
A small family. It has only one genus and about four species. It is recognised by reddish sap,palminerved leaves,horse shoe shaped anthers and seeds with red fleshy testa. Bixaceae is mainly found in south america. An orange edible dye produced from the -testa of Bixa orellina called "annatto" is used to colour butter cheese and other food products.It is known as Rocou in french. and Shendri in Marathi. Only one plant known Bixa orellina (Lipstick plant) शेंदरी
Leaves alternate heart shaped, simple entire
Sepals 4-7.Petals 5.Stamens indefinite distinct inserted upon the receptacle at the base of the calyx. Anthers 2- celled Ovary superior.
Fruit capsule or berry.
Wednesday, 2 April 2008
BORAGINACEAE ( BORAGE FAMILY)
In India chiefly in temperate and alpine Himalayas ahd drier parts of southern,western and northern India.
Members : Generally annual or perennial herbs.Some are trees and shrubs (Ehretia and Cordia)
Flowers of these herbs are a favourite with butterflies,bees and other insects.Milkweed butterflies are seen on these plants,which yield essential alkaloids (necessary for butterfly reproduction) to them Leaves :simple, mostly entire, and alternate; stipules are lacking. In most species pubescent and hairy.
Inflorescence and flowers : Usually characteristic dorsiventral terminal axillary or leaf opposed cincinus inflorescences which consists of one or more coiled scorpoid or helicoid cymes that become uncoiled as the flowers open.Rarely flowers are solitary.
Flowers : bisexual and actinomorphic, hypogynous pentamerous.
Calyx : Five distinct or connate sepals. Calyx generally persistent.
Corolla : Five fused petals.Shape variable -rotate,salverform,funnelform or tubular. Often small appendages in throat.
Androecium : 5 distinct stamens adnate to the corolla tube or perigynous zone and alternate with the corolla lobes.
Gynoecium : consists of a single compound pistil of 2 carpels, a single, often gynobasic style, and a superior, often deeply 4-lobed ovary with 4 locules, each containing a single basal-axile ovule. An annular nectary disk is sometimes present.
Fruits and seeds : 4 1-seeded nutlets or a 1-4-seeded nut or drupe.
Flowers are adapted for insect pollination
Pericarp of the fruit is covered with barbed or hooked bristles -animal dispersal.
Species of several genara grown as ornamentals: Heliotropium(Heliotrops),Cynoglossum(Hounds tongue),Myosotis(Forget-me-nots),Borago(Borage),Pulmonara(Lungwort)
Ehretia Levis : wood useful. अजान वृक्ष
Ehretia aspera : common in Western ghats.
Heliotropium indicum (Indian turnsole) and
Trichodesma indicum (Indian borage) are most familiar herbs.
Cordia sebestena : Common ornamental garden tree.
Cordia dichotoma : Bhokar (भोकर)