S.Y.BSc SEMESTER III BOTANY PRACTICAL COROLLA

1. S.Y.BSc SEMESTER IIIBOTANY PRACTICAL COROLLA DEPARTEMENT OF BOTANY SATISH PRADHAN DNYANASADHANA COLLEGE, THANE (W)

2. Corolla • The second whorl in the flower composed of petals which are usually coloured. • The colour is due to the presence of water soluble anthocyanin and anthoxanthin or carotenoids. • Petals protect the essential whorls in bud condition and also attract pollinating agents. • Each petal has a lower narrow part called the ‘Claw’ and the expanded portion called The ‘Limb’. • If claw is absent petals are sessile e.g. Rose. • Corolla may be regular or irregular. • Corolla may be polypetalous or gamopetalous. • I) Forms of corolla— • 1) Polypetalous regular forms— • a) Cruciform—Four clawed petals are arranged in the form of a cross e.g. Mustard • b) Caryophyllaceous—Five clawed petals with limbs and claws at right angles to each other arramged in whorl e.g. Dianthus • c) Rosaceous- Five or more sessile petals with limbs spreading outward. E.g. Rose.

5. 2) Polypetalous irregular forms--- • Papilionaceous—Five free petals arranged to resemble a butterfly. The posterior superior petal is largest and known as vexillum or standard. Two anterior or inferior ones more or less united forming a boat shaped structure are called keel or carina.Two lateral petals called alae or wings overlap the keel and overlapped by vexillum e.g. Clitoria • 3) Gamopetalous regular forms— • a) Tubular—Corolla tube is nearly cylindrical throughout and the limbs are • not spreading out e.g. disc floret of Asteraceae- Sunflower, Lily • b) Campanulate or bell shaped—Corolla tube is rounded at the base and gradually widening upwards like a bell. E.g Physalis, Coccinia,Physalis • c) Infundibuliform or funnel shaped – the corolla resemebles an inverted funnel. E.g Datura, Ipomoea ,quamoclit • d) Hypocrateriform or Salver shaped – The corolla tube is narrow with limbs placed at right angles. E.g Vinca rosea,Ixora coccinea • e) Rotate or wheel shaped – Corolla tube is short and limbs are at right angles. E.g Brinjal (Solanum melongena)

6. 3) Gamopetalous regular forms— a) Tubular—Corolla tube is nearly cylindrical throughout and the limbs are not spreading out e.g. disc floret of Asteraceae- Sunflower, Lily b) Campanulate or bell shaped—Corolla tube is rounded at the base and gradually widening upwards like a bell. E.g Physalis, Coccinia,Physalis c) Infundibuliform or funnel shaped – the corolla resemebles an inverted funnel. E.g Datura, Ipomoea ,quamoclit d) Hypocrateriform or Salver shaped – The corolla tube is narrow with limbs placed at right angles. E.g Vinca rosea,Ixora coccinea e) Rotate or wheel shaped – Corolla tube is short and limbs are at right angles. E.g Brinjal (Solanum melongena)

7. 4) Gamopetalous irregular forms – • Ligulate or strap shaped- Five petals unite to form a short tube at base which split on one side and becomes flattened like strap. E.g Ray floret of Sunflower. • b) Bilabiate – the irregular corolla is united in such a way that the limb is divied into an upper posterior part and an unequal lower anterior part with mouth wide open. E.g Adathoda, Ocimum • c) Personate – it resembles bilabiate corolla but the mouth is closed. The projection of the lower lip closing the mouth is called the palate. E.g Snapdragon

8. Aestivation • The arrangement of sepals and petals in the bud with relation to one another. • 1)Valvate- Floral leaves (sepals or petals) in one whorl just touching one another. E.g Calyx of Hibiscus • 2) Contorted or twisted – Floral leaves in one whorl but overlapping is regular in one direction so that one margin overlaps the next member, on one • side while its other margin is overlapped by the one before. E.g Hibiscus corolla • 3) Imbricate – Floral leaves are not in one whorls and overlapping is not regular. One member is completely outside, one inside and three overlapping.E.g. Cassia tora • 4) Quincuncial – Floral leaves are not in one whorl and overlapping is not regular. Two members are completely outside, two inside and one overlapping. E.g. Calyx of Ipomoea palmata • 5) Vexillary – This aestivation is typical of papillionaceous corolla. Posterior vexillum is outside, lateral wings overlapping and keel is completely inside. E,g. Clitoria

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10. Perianth – when calyx and corolla are not differentiated the general accessory • whorl is called perianth. Perianth may be petalloid or sepaloid, • and polyphyllous or gamophyllous. E..g Crinum.Lily

11. Androecium – It is an essential whorl. It is the third set of floral organs composed • of stamens or microsporophylls. • Stamens—Structure- Each stamen is composed of slender stalk like filament with a knob like spore case known as the anther. Each anther consists of two lobes connected by a connective. Each anther lobe has two pollen sacs or chambers. Each pollen chamber is a microsporangium with microspores or pollen. • A sterile stamen does not produce pollen and is called staminode. Eg .Pancratium • Modification of filament— • 1)Branched filament—In castor the filament is branched with anthers at the tips of branches e.g. Ricinus communis. • 2)Staminal corona—The filament sometimes bear appendages which may be hairy or horny called as stamiinal corona e.g. Calotropis gigantia. • 3) Petalloid filaments—In some plants filaments appear petal like e.g. Canna indica. Androecium

13. Connective—The sterile tissue connecting two anther lobes. • Types – • 1) Discrete-- The anther lobes are closely placed without any apparent connective e.g. • Euphorbia pulcherrima. • 2) Divaricate—Two anther lobes get separated due to a bifurcate connective • e.g. Spathodea • 3) Distractile connective-The connective is long and stalked seperating the two • lobes widely . One anther lobe is abortive while the other is fertile e.g. Salvia. • 4)Appendiculate—The connective is prolonged and often feathery e.g.Nerium. • 5) Prolonged—The connective extends beyond the anther lobes and protrudes beyond their tip e.g. Annona,. Michelia.

14. Anthers • (1) Unilocular---Instead of four locules , each anther has only one locule ( due to • fusion of locules or abortive locule) e.g. Hibiscus rosa siensis • (2) Introrse-The two lobes of the anther face toward the centre of the flower e.g. Physalis minima • (3) Extrorse--- The two lobes of the anther face towards the corolla e.g. Gloriosa superb • (4) Sagittate--- Anther lobes form an arrow –head shaped structuree.g. Vinca • (5) Sinuous—Anthers of stamens are united and have a wavy appearance e.g. Coccinia indica (Cucurbitaceae) • (6) Reniform--- Anther lobes are rounded e.g. Tradeschantia • Attechment of anthers to filament- • Basifixed – Base of anther lobes attached to filament e.g. Mustard • Dorsifixed-Dorsal side of anther lobes attached to filament e.g. Passiflora • Versatile- Linear anther lobes attached at midpoint to filament e.g. Delonix,Lily • Adnate- Entire lobe attached to filament e.g. Michelia

16. Union of stamens- • Adhesion- Union of stamens with other members like sepals, petals or carpals • Sepals- Episepalous- Quisqualis Indica • Petals- Epipetalous- Ipomoea palmate • Perianth- Epiphyllous- Pancratium • Carpel-Gynostegium- Calotropis gigantia • Cohesion- Union of stamens among themselves. • This can taks place in two ways- • Union of filaments- • adelphy results in a staminal tube. If the union results in- • One group- Monoadelphy e.g. Hibiscus rosa sinensis • Two group- Diadelphy e.g. Clitoria ternatia • Many groups- Polyadelphy e.g. Salmalia,Ricinus • Union of anthers- • Syngeny. In this condition filaments are free but anthers of all stamens are united e.g. disc floret of Sunflower , Balsam • Complete union of stamens- Synandry. In this filaments as well as anthers of all stamens unite together e.g. Cucurbita

18. Gynoecium Gynoecium- It is an essential whorl and the topmost whorl of the flower. It is composed of carpels or megasporophylls. • A typical carpel consists of ovary, style and stigma. The lowermost swollen part is the ovary which contains one or more ovules. Above the ovary is the style terminating into stigma. A sterile pistil is called a pistillode. • Number of carpels— One carpel—Monocarpillary Two carpels—Bicarpillary Three carpels---Tricarpellary Five carpesl—Pentacarpellary Many carpels—Polycarpellary

19. Parts of Carpel

22. carpel • Apocarpous- The multiple carpels of a flower remain completely free from one another e.g. Michelia • Syncarpous- The carpels unite with each other wholly or partially (cohesion) • a) Ovary and style united ; stigma free e.g. Hibiscus rosa sinensis • b) Ovaries united; style and stigma free e.g. Dianthus • c) Ovaries are free; Style and stigma united e.g. Vinca, Calotropis • Style- It is a tube like structure that connect the stigma to the ovary. • a) Apical- Style arises from apex of the ovary e.g. Hibiscus • b) Lateral- The style arises from the side of ovary e.g. Mangifera • c) Gynobasic- The style arises from the central base of the deeply lobed ovary • e.g. Ocimum

23. Stigma • Stigma-is usually on top of the style. When style is absent, the stigma is sessile. Stigma is the receptive surface for pollens. • Types of stigmas— • a) Lobed , sigle lobed , bilobed--- Ipomoea plamata • b) Bifid , trifid , pentafid—Helianthus annus • c) Feathery or plumose—Zea mays • d) Funnel shaped—Crocus sativus

24. Placentation Ovary – Placentation 1) Marginal-- is observed in monocarpellary ovary. The placenta form a ridge along the ventral surface and ovules are arranged in two rows e.g. Pisum sativum 2) Parital-- When two or more carpels unite alongtheir ventral surfaces with the placenta located along these structures and the ovary is unilocular e.g. Cucumis sativa 3) Axile--The number of carpels independtly form chambers by folding inwards and the fusing so that ventral surfaces are all placed along the axis. Ovules are attached to the axis in the centre. 4) Free central—Ovules are found to develop on an axial column which is not connected with the wall of the ovary e.g. Dianthus. 5) Basal—A single ovule at the base of unilocular, simple ovary e.g. Helianthus annus 6) Apical—Ovules appear to be attached to the roof of the ovary due to dissolution of axis. Ovules are pendulous e.g. Quisqua

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