Dicotyledons of Ranunculaceae

 

Ranunculaceae (Buttercup Family)

Systematic position:

Polypetalae, Thalamiflorae, Ranales.

Field recognition:

Herbs, leaves often divided or palmately compound with sheathing leaf bases,stamens numerous and spirally arranged,carpels numerous, distinct,spirally arranged,unilocular.

Selected Indian genera:

Ranunculus, Aconitum, Actaea,Anemone,Caltha.

Size,distribution and general information:

Represented by about 50 genera and 1900 species,distributed in the temperate regions of the Northern Hemisphere.The common genera of which over 150 or more species have so far been reported, include Ranunculas, Aconitum, Anemone.Some species occur in Arctic and Alpine zones.Plants of this family flower mainly during winters in our country.

Description of the family:

General Habit-Generally annual or perennial herbs,rarely shrubs or vines,perennials perennate by means of rhizome,some species areaquatic herbs.

Root-Tap root as well as adventitious roots,tuberous roots of Aconitum,Paeonia and Ranunculus store food, swell and form tuber –like structures.

Stem-Aerial as well as underground,herbaceous,woody,climbing,branched.

Leaves-Usually basal and cauline,often palmately divided with sheathing leaf bases ,usually exstipulate,but stipulate in Caltha,Ranunculus,mostly alternate opposite,simple,aquatic species  of Ranunculas show heterophylly.

Inflorescence-Variously formed,solitary to paniculate,racemes or cymes,a single terminal flower is produced in Anemone and Eranthis,but more often a cymose branching is seen.

Flower-Bracteate or ebracteate,bracteolate or ebracteolate,bisexual or unisexual in some species of Thalictrum,usually actinomorphic but zygomorphic in Delphinium and Aconitum,hypogynos.

Delphinium

Calyx-3 to many   sepals,polysepalous,valvate or imbricate,sepals are petaloid in Aconitum.

Corolla-5 petals,polypetalous,nectariferous glands present,sometimes petals are many or absent,posterior petals are spurred.

Androecium-Stamens 5 to many,free,spirally arranged,anthers 2-celled,adnate,extrorse and longitudinally dehiscent,sometimes stamnodes are present.

Gynoecium-Numerous,free carpels with either one basal ovule or seval anatropous ovules showing marginal placentation,ovary superior,unilocular,style 1,stigma 1.

Fruits and seeds-Etaerio of follicles,etaerio of achenes,berry either apsule,seeds minute embryo and oily endosperm.

Floral formula:
 

Economic importance:

•    Ranunculaceae are important as ornamental and as drug plants.Its has showy flower and are grown as ornamentals in our gardens.

•     Aconitum napellus roots the source of aconite,used as a nerve sedative.

•     Actaea spicata roots used as a nerve sedative. 

•     Anemone pulsatilla is the source of the homeopathic drug ‘Pulsatilla’ used to cure nervous disorders in women during menstrual periods.

•    Clematis triloba leaves are used to cure snake bites.

•    Nigella sativa seeds are used as common condiment as well as in the treatment of cough, asthma and fever.

Dicoytledons of Annonaceae

Asimina triloba

Annonaceae (Custard Apple Family)

Systematic position:

Polypetalae, Thalamiflorae, Ranales.

Field Recognisation:

 Woody shrubs, trees or climbers, wood aromatic, leaves two-ranked, without stipules 3+3+3, stamens numerous, rarely few, gynoecium polycarpellary, apocarpous, superior ovary.

Selected Indian Genera:

Annona squamosa, Cananga odorata, Arta botrys odoratissimus.

Size,distribution,and General Information:

Over 25 genera and 200 species have so far been reported from India, mostly from its peninsular region. Annona is represented by over 120 species, and Xylopia by about 150 species.

Description of the family:

General Habit- Aromatic trees or shrubs, rarely liana-like, or woody climbers(Oxymitra), hook climber(Artabotrys).Bark, leaves and floral parts contain oil ducts.

Root-Extensively branched tap roots.

Stem-Woody, branched, erect, rarely climbing, aerial, hard.

Leaves-Simple, alternate, two-ranked, exstipulate, petiolate, apex acute, obtuse or even mucronate, ovate, obovate, coriaceous, glabrous, unicostate reticulate, gland-dotted and so aromatic.

Inflorescence- Solitary axillary, or terminal, or leaf opposed, sometimes cauliflorous ,i.e. flowers occur on stem.

Flower- Bracteate or ebracteate, ebracteolate, pedicellate, complete, hermaphrodite, rarely unisexual, actinomorphic, rarely zygomorphic, hypogynous.

Calyx- Sepals 3, or sometimes 6 arranged in 2 whorls of 3 each, polysepalous, or rarely basally connate, valvate, rarely imbricate.

Corolla- Generally 6 petals, arranged in two whorls of 3 each, sometimes only 3 petals, polypetalous, valvate or slightly imbricate.

Androecium- Stamens numerous, polyandrous, flimant short and thick,connective continues beyond the anther and produces a dilated head,ad nate,extrorse.

Gynoecium- Carpels numerous, arranged spirally on the receptacle, only 1-3 carpels in Cyathocalyx, apocarpous, superior, unilocular, one to many anatropous ovles in the locule, parietal or sometimes basal or marginal placentation, style short or absent, stigma sessile, simple or trilobed.

Fruits and seeds- Fruits an etaerio of berries in Annona, the berries coalesce with fleshy receptacle, seeds large, endospermous. 

Floral formula:

Economic importance: 

•   Annona.squamosa is cultivated in assam for its edible fruits.Its leaves and seeds have insecticidal properties.

•                A.odoratissimus yields an ethereal oil and also cultivated for its scented flowers.

•             Asimina is cultivated for its edible fruits in America.

•            Cananga odorata is cultivated as an ornamental  tree cause of its sweet smelling flowers.

•           Unona pannosa yields a strong fibre used for paper making and cordage.

• Uraria narum root yield an oil used as a medicine.

Dicotyledons of Magnoliaceae

Magnoliaceae:

Systematic position:

Polypetalae ,Thalamiflorae, Ranales

Field Recognition:

Trees or shrubs, leaves simple, alternate, stipules leave a circular stipular scar, flowers large, actinomorphic, perinath parts 6-18,stamens many, apocarpous.

Selected Indian Genera:

Magnolia, Michelia,Talauma

Size and Distibution and General information:

It has 12 genera and 230 species, mainly distributed in the warm temperature regions of the Northern Hemisphere.The species are common in eastern Asia and North America.

Magnoliaceae family

Description of the family:

General Habit- Decidious or evergreen, aromatic shrubs or trees.

Root- Tap root , branched.

Stem- Aerial, woody, erect or climbing, branched, parenchyma contain oil glands.

Leaves- Alternate, large, simple, entire, petiolate, pinnately-veined, stipulate, stipules large, oil glands present.

Inflorescence- Solitary flowers, axilary or terminal, flowers crowded near he tips of branches in Illicium

Flowers- Large, showy,bracteate, pedicellate, bisexual rarely unisexual, actinomorphic, hypogynous, 

Perianth- Is undifferentiated into calyx and corolla. Spiral or cyclic,polyphyllous,lobs are arranged in whorls of threes, valvate or imbricate in each whorl.

Androecium- Stamens numerous, free, spirally arranged on the basal part of floral axis, anthers long, dithecous, basifixed, introse, dehiscence longitudinal, connective prolonged.

Gynoecium- Carpels numerous, apocarpous (free), spirally arranged on the floral axis above the stamens, superior, unilocular, one or more ovules on a ventral suture, placentation parietal, style short, one,stigma one.

Fruits and seeds- Fruit of aggregate type. It may be a follical, samara or rarely berry. Seed often suspended within the follical by a thread-like funiculus, has a minute embryo in a large endosperm.

Floral Formula:
 

Economic Importance: 

•           Important as common ornamentals and as a source of wood.

•           Magnolia species are commonly cultivated in gardens. M.grandiflora is known for their sweet, scented, beautiful flowers.

•          Wood of M.acuminata is used in making toys, tea-boxes and quality furniture.

•           M.champaca is a common garden ornamental plant, and is also the source of a volatile oil which is widely used in perfumery and cosmetics.

•          I.griffithii fruits are used as condiment for flavouring curries.

•          Schizandra grandiflora fruits are edible.