FLOWER, FRUITS AND SEEDS

A flower is a modified shoot where in the shoot apical meristem changes to floral meristem. Internodes do not elongate and the axis gets condensed. When a shoot tip transforms into a flower, it is always solitary. 

Generally flower has a short or long stalk which is called pedicel. The upper part of pedicel is swollen which is called thalamus. Floral leaves are present on it 

There are 4 types of floral leaves

(1) Sepal

(2) Petal

(3) Stamen

(4) Carpel

• A typical flower has flour different kinds of whorls arranged succession thalamus. These are.com corolla, androecium and genoclom.

• Calyx and corolla are accessory organs or accessory whorls while androecium and gynoecium are reproductive organs or reproductive whorls of essential whorls.

• complete flower All four whorls are present

• Incomplete flower Any whorl is absent eg. Unisexual flower

• Bisexual flower perfect flower

• Unisexual flower Imperfect flower

A flower may be trimerous, tetramerous or pentamerous when the floral appendages me in multiple or 5, respectively. In dicots flowers are usually pentamerous while in monocots flowers are trimerous.

SYMMETRY OF FLOWER

Actinomorphic/Radial/Regular - When a flower can be divided into two equal radial halves by any vertical plane or radial plane passing through the centre, then it is said to be actinomorphic flower eg. Mustard,Datura, chilli.   

Zygomorphic/Bilateral - When a flower can be divided into two equal (similar halves only by one particular vertical plane then it is said to be zygomorphic flower. eg. Pea, bean, gulmohur. Cassia.

Asymmetrical/Irregular - When a flower cannot be divided into two equal (similar halves from any vertical plane passing through the centre, then it is said to be asymmetrical flower eg. Canna.

• The part of flower which lies near to the mother axis is posterior part while the part which is far from the mother axis is anterior part of flower. The position of the mother axis with respect to the flower is represented by a dot on the top of the floral diagram.

TYPES OF FLOWERS ON THE BASIS OF INSERTION OF FLORAL LEAVES

The relative position of gynoecium changes with respect to floral parts. Based on the position of calyx, corolla and androecium in respect of the ovary on thalamus the flowers are divided into three types.  

 

Hypogynous flower - When gynoecium occupies the highest position while the other parts like petals sepals and stamens are situated below the ovary, then the flower is called hypogynous and in this condition ovary will be superior eg. Mustard, china rose, brinjal, mango. 

Perigynous flower - In it thalamus grows upwardly and form a cup shaped structure. On the margin or rim of thalamus floral parts are attached except gynoecium, which lies at the basal part or in the centre. So in this condition gynoecium is situated below the other floral parts. But ovary in this condition is said to be half inferior Eg. Rose, plum. peach,

Epigynous flower - When the margin of thalamus grows upward enclosing the ovary completely  and getting fused with it and other parts of flower like petals, sepals & stamens are situated above the Ovary then, the ovary is said to be inferior the rayflorets of sunflower. and rest of the floral parts superior Eg. Guava apple, cucumber, sunflower.

BRACT

Bract is a reduced leaf found at the base of the pedicel of flower.

Bracteate flower - The flower with bract is called bracteate flower.

Ebracteate flower - Flower without bract is known as ebracteate flower.

Involucre - The whorl of bracts is called involucre.

Spathe - When large bract completely encloses whole inflorescence, then it is called spathe.

Eg. Banana, maize 

Petaloid bract When the size of bract is greater than the size of flower and it is of various coloured like petals, then it is called petaloid bract. In. Bougainvillea.

Glumes - Small dry, scaly bracts are called glures. Eg. Wheat, grass (Gramineae family)

CALYX

The outermost whorl of flower is called calyx. Each member of this whorl is called sepal, when all the sepals are free from each other, then it is called polysepalous condition eg. Mustard, radish. When the sepals are fused (united) with each other then this condition is called gamosepalous condition. Eg. Cotton, Datura, brinjal.

• Sepals are green leaf like and protect the flower in the bud stage
• In calyx of Mussaenda, one of sepal enlarged and forms a leaf like structure. it may be brightly  coloured. It attracts the insects and thus acts as advertisement flag/advertising flag.

• In Trapa. Calyx is modified into spines and helps in protection of fruits

• In the family of sunflower (compositae) sepals are modified into hairy structure which is known as pappus. The pappus is modified calyx and helps in dispersal of fruit by parachute mechanism.

• If sepals do not fall and remain attached to fruit then they are called persistent sepals Eg. Tomato, chilli, brinjal, cotton. Datura

COROLLA

The second whorl of flower is called corolla and each member of corolla s called. petal. When all the petals are free, then it is called polypetalous condition and when petals are fused, then it is called gamopetalous condition

Petals are usually of brightly coloured to attract insects for pollination.

FORMS OF COROLLA -

(A) Actinomorphic Polypetalous Corolla

(1) Cruciform In cruciform corolla 4 petals are found. These petals are arranged crosswise. The lower narrow part of petal is called claw while the upper broad part is called limb. Eg. Radish, mustard (Cruciferae)

 (B) Actinomorphic Gamopetalous Corolla

 

Campanulate/Bell shaped In this type of corolla 5 fused petals are present. It's shape is similar to bell. Eg Tobacco, raspberry, Campanula

Tubular - In this type 5 fused petals form tubular (tube like) or cylindrical structure Eg. Disc florets of sunflower

Funnel shaped or infundibuliform - In this type 5 fused petals are found. It's shape is similar to funnel. Eg. Datura, railway creeper. Petunia

Wheel shaped/Rotate - In this type 5 gamopetalous petals are found and the fused parts fom small tube and the petals are arranged in a whorl above the tube. Eg. Brinjal.

ZYGOMORPHIC POLYPETALOUS COROLLA -

Papilionaceous (Butter fly shaped corolla) - In this type of corolla five petals are found. Posterior petal is largest and is known as standard or vexillum. Vexillum covers two lateral petals which are called wings or alae and the innermost anterior petals are united to forma keel or carina. Both lateral petals cover the keel. Eg. Pea, bean gram, (Papilionatae).

ZYGOMORPHIC GAMOPETALOUS COROLLA

Bilabiate - The petals of gamopetalous corolla are divided into two lips. The place between two lips is called corolla mouth Eg Ocimum (holy basil = tulsi), Salvia (Labiatae family) 

Ligulate-  The upper part of corolla is long flattened tongue like which is attached with short narrow tube. Eg. Ray florets of sunflower

AESTIVATION

The mode of arrangement of sepals or petals in floral bud with respect to the other memben of the same whorl is known as aestivation. It is of following types :-

1. Valuate - When the petal of a whorl lie adjacent to other petal and just touch one another at the margin without overlapping then it is known as valvate aestivation. Eg. Calotropis plant. Cruciferae, Solanaceae & Liliaceae family.

2. Twisted - In this type one margin of a petal covers adjacent petal and the other margin is covered by another petal. One margin of the petal overlaps that of the next one, and the other margin is overlapped by the another one. Eg. Cotton ladyfinger. china rose (Malvaceae family).

3. Imbricate - When both margins of the one petal are covered by the other two petals and both margin Children of another one, covers other. Rest are arranged in twisted manner. OR ! the margins of sepals or petals overlap one another but not in any particular direction, then it is known as imbricate aestivation.

Eg. Cassia, gulmohur (Delonix regia).

4. Vexillary or Papilionaceous or Descending imbricate - The posterior petal is outermost and largest and is known as standard or vexillum which overlaps the two lateral petals wings or alae These two laterals petals.overlaps two smallest anterior petals ie keel or carina Vexillary arrangement is found in pea family. Eg. Pea bean (Papilionaceae subfamily of leguminosae family).

5. Quincuncial :- Out of the five petals, two are completely internal two are completely external und in the remaining petal, one margin is internal and the other margin is external.

Eg. Murraya

ANDROECIUM

It is composed of stamens. When the stamens of an androecium are free from one another, then it is called polyandrous condition.

COHESION OF STAMENS :

When the floral parts of similar whorl are fused, then it is called cohesion

1) When stamens are united by their filaments only, then it is called adelphi. It is of following types:

a) Monadelphous - In this type of cohesion all the ligaments are united into a single bundle or one bunch but anthers remain free. In this type of cohesion a tube is formed around the gynoecium which is called starinal tube Eg. China rose (Malvaceae family).

b) Diadelphous - In this type of cohesion filaments are united into two bundles but the anthers remain free Eg. Pea (Papilionatae).

In these plants out of 10 stamens, 9 stamens are united into a bundle while 1 stamen remains free

c) Polyadelphous - Filaments are united into more than two bundles. Eg Citrus.

2) Syngenesious - Only anthers are united in bundle, but filaments remain free eg Compositae family.

3) Synandrous Anthers as well as filaments of stamens are united through their whole length.

Eg. Colocasia, Alocasia, Cucurbitaceae family

ADHESION OF STAMENS -

When the stamens are attached to other parts of flower, then it is called adhesion of stamens.

1) Epipetalous - Stamens are attached to the petals. Eg. Brinjal (Solanaceae) 

2) Epiphyllous or Epitepalous - Stamens are attached to the tepals (perianth (3) Eg. Lily (Liliaceae) 

3)Gynandrous - Complete stamens or only anthers are attached to the gynoecium. Eg. Calotropis, Aristolochia

LENGTH OF STAMENS -

There may be a variation in the length of filaments within a flower, as in Salvia and mustard.

Didynamous - f four stamens are present and out of them two are long and two are short, then it is called didymus condition. Eg Lamiaceae/Labiatae family (Salvia), 

Tetradynamous - When there are six stamens and they are arranged in two whorls. In outer whorl, there are two short stamens while in inner whorl, there are four long stamens, this condition is called tetradynamous Eg. Cruciferae family (Mustard, radish, turnip)

GYNOECIUM

• Gynoecium is female reproductive organ of the flower and is made up of one or more carpels.

•  If only one carpel is present in gynoecium then this condition is called monocarpellary condition:
• If more than one carpel is present in gynoecium then this condition is called polycarpellary.

• When all the carpels in polycarpellary/multicarpellary condition are free, then this condition is called apocarpous eg. lotus, rose, Michelia,

• When all the carpel are fused, then this condition is called syncarpous eg. Papaver, Hibiscus, mustard, tomate.

PLACENTATION

The Ovules are attached on ovary walls on one or more cushion like structure called placenta. The manner in which placenta or ovules are arranged on ovary wall is known as placentation or The arrangement of ovules within the ovary is known as placentation. It is of following types.

Marginal : This type of placentation is found in monocarpellary gynoecium. In this type of placentation placenta forms a ridge along the ventral suture of the ovary and the ovules are borne on this ridge forming two rows, as in pea. There is no true placenta. Eg. Pea (Leguminosae family

Axile This type of placentation is found in multicarpellary, syncarpous gynoecium.Ovary is multilocular and the ovules are borne on the central axis. Number of chambers are equal to the number of carpels fused. Eg. china rose. lemon. tomato.

 Parietal : This type of placentation is found in unilocular syncarpous ovary. The ovules, develop on the Inner wall of the ovary or on peripheral part. Eg. Mustard and Argemone.

• In some plants, ovary is one chambered but it becomes two chambered due to formation of false septum or replum. Cruciferae family (Eg Mustard. Capsella) and Argemone.

Free central/Central This type of placentation is found in syncarpous gynoecium. In it, the ovary is unilocular (septa are absent) and the ovules are borne on the central axis eg. Primrose, Dianthus

Basal: The ovary is unilocular and the placenta develops at the base of ovary and single ovule is attached at the base of ovary. Eg. marigold, sunflower (Asteraceae Compositae family), Gramineae / Poaceae family.

Superficial - This type of placentation is found in multicarpellary, syncarpous, multilocular gynoecium.

The ovules  are attached on the entire inner surface or walls of loculii Eg. Nymphaea (water lily).

FRUIT 

The fruit is the characteristic feature of the flowering plants. It is the mature or ripened ovary, developed after fertilization. If a fruit is formed without fertilization of ovary, it is called a parthenocarpic fruit. In some fruits like grapes, banana seeds are not found and such type of fruits  are called parthenocarpic or seedless fruits. Parthenocarpy can be induced through the application of growth hormones.

PERICARP (Fruit wall) :After ripening, the ovary wall changes into pericarp. This pericarp may be thick and fleshy or thick and hard or thin and soft.

In fleshy fruits pericarp (fruit wall) is made up of 3 layers:

(1) Outermost layer- Epicarp

(2) middle layer- mesocarp 

(3) innermost layer- Endocarp

Epicarp - It is the outermost layer, it may be thick or thin and hard or soft. It forms outermost layer of fruit which is also called rind.

 Mesocarp: It is the middle layer which is thick and fleshy in mango, peach and date palm. In coconut this layer is made up of fibres which is also called coir. Endocarp: It forms the innermost layer, It may be thin membranous (eg. Orange, Date Palm) or thick and hard (eg. Mango, Coconut)

TRUE FRUIT OR EUCARP

When the fruit is developed only from the ovary then the fruit is called true fruits. eg. mango, coconut, zizyphus.

FALSE FRUIT OR PSEUDOCARP

In some fruits, in place of ovary, some other parts of flower like thalamus, calyx and inflorescence are modified into fruit or a part of fruits. Eg Apple. Strawberry, Pear, Mulberry, Fig, Cashew nut. 

• In apple, strawberry, cashew, etc. the thalamus also contributes to fruit formation Such fruits are called  false fruits.

CLASSIFICATION OF FRUITS :

Fruits are divided into 3 types :

SIMPLE FRUITS

These fruits develop from ovary of monocarpellary gynoecium or multicarpellary, syncarpous gynoecium and only one fruit is formed by the gynoecium, Simple fruits are of two types :

(a) Fleshy fruits

(b) Dry fruits 

(a) FLESHY FRUITS In fleshy fruits, fruit wall (pericarp) is differentiated into epicarp, mesocarp and endocarp. these fruits are indehiscent

Fleshy fruits are of following types:

DRUPE FRUITS. These fruits develop from monocarpellary, superior ovaries and are one seeded. In these fruits endocarp is hard and stony, so these fruits are also called stony fruits. Eg Mango coconut, almond, peach. walnut, plum. In mango the outermost cover or thin rind is called epicarp. Middle edible fleshy part is mesocarp and the inner story hard endocarp. In plum (Ber), epicarp and mesocarp both are edible while endocarp is stony.

The hard covering of almond and walnut is endocarp and their edible part is seed. In coconut epicarp is hard and thin while mesocarp is thick and fibrous. The endocarp is hard and seed is proteced in it.The sweet water and edible part of coconut are liquid and solid.endosperm respectively.

 BERRY: These fruits develop from mono or multicarpellary syncarpous ovary. Ovary may be superior or inferior. Placentation is axile. Generally epicarp is thin membrane like and seeds are embedded in fleshy part. Initially seeds are attached with placenta of fruit but after maturation these seeds are detached from placenta and are spread randomly in fleshy part. eg. Tomato, grapes, brinjal guava, banana (date palm and betelnut are single seeded berry).

 PEPO : These fruits develop from inferior ovaries. They have parietal placentation but looks like axile due to swelling of placenta. Eg fruits of cucurbitaceae family like cucumber (khira), water melon (tarbooz). Cucurbita maxima (pumpkin), bitter gourd (karela), muskmelon (kharbuja).

 POME This fruit develops from inferior ovary and having enlarged thalamus Eg Apple, pear. These are false fruits. Fleshy swollen thalamus of these fruits is edible part.

HESPERIDIUM They have axile placentation. This fruit is specially found in the plants of Rutaceae family. Eg, Orange, lemon.

Epicarp of these fruits is made up of thick rind which is having many oil glands. Mesocarp is the white fibrous structure which is attached with epicarp. Membranous endocarp projects inward and forms many chambers. Many glandular hairs are present on the inner side of endocarp These glandular juicy hairs are edible.

BALAUSTA This fruit, develops from inferior ovary. Calyx is persistent which is arranged in the form of crown. Testa of seed is fleshy and juicy. Testa is the edible part. Eg. Pomegranate (Punica granatum) - anar

DRY-FRUITS

Pericarp (fruit wall) of simple dry fruits is not differentiated into epicarp, mesocarp and endocarp.

In some dry fruits, pericarp dehisces/ruptures after ripening and seeds are dispersed, such fruits are called dehiscent fruits. In some fruits, pericarp breaks/splits into one or more seeded segments, such fruits are called schizocarpic fruits. In some fruits, pericarp does not dehisce even after maturing/ripening, Such fruits are called indehiscent fruits.

Simple dry fruits can be divided into following three groups :

(1) Indehiscent

(ii) Dehiscent

(ii) Schizocarpic

1.INDEHISCENT FRUITS These fruits do not dehisce/rupture. These simple dry fruits are general of small sized and single seeded.

(1) CYPSELA This is a small, one seeded dry fruit which develops from bicarpellary, syncarpous, Inferior ovary. In cypsela fruit pericarp (Fruit wall) and seed coat are free from each other and a bunch of hair is attached with the fruit which is known as pappus. Pappus helps in fruit dispersal. Pappus is modification of calyx. Eg Compositae family (Sunflower, marigold).

(2) CARYOPSIS: These are small, one seeded dry fruits, which develop from monocarpellary, superior Ovary In these fruits Pericarp is fused with the seed coat and form a joint surface These fruits are present in family Gramineae. Eq wheat, rice, maize etc.

(3) ACHENE In these fruits pericarp is free from the seed coat & pappus are absent. Eg. Ciemats,Mirabilis, Boerhaavia.

(4) NUT : This is a single seeded fruit, its pericarp is hard. eg. cashewnut,tarpa (water chest-nut), litchi.

• In litchi epicarp and mesocarp is fused and give leathery appearence. Endocarp is membrane like thin. An additional coat arround the seed is formed which is called aril. Actually it is a sort of third integument. In mature fruit, this aril is fleshy and is only edible part. 

SAMARA : These are dry indehiscent one seeded winged/feathery fruit. The main character of the fruits is that wing like structure develops from pericarp which helps in dispersal of fruits. Eg. Holoptelia (chil-bil). Dioscorea.

DEHISCENT FRUITS Pericarp of these fruits gets ruptured after ripening and seeds dispersed outside. These fruits are mainly of 5 types:

LEGUME OR POD. These fruits develop from monocarpellary, unilocular, superior ovary with marginal placentation They Are generally long and multi seeded fruits. Dehiscence of fruit occurs at both sutures i.e. dorsal  and ventral suture. Dehiscence starts from apex/tip and reaches to basal part. Eg Pea, beans, gram.

 SILIQUA: This fruit develops from bicarpellary, syncarpous, superior ovary and ovary has parietal placentation. Dehiscence occurs from both dorsal and ventral suture, Dehiscence starts from lower part and proceeds upward (from base to the apex). Initially ovary is unilocular but due to formation of false septum replum ovary becomes bilocular later on. On false septum seeds are attached. This type of fruit is found in Cruciferae family Eg Brassica (mustard).

SILICULA : Small, broad siliqua is known as silicula. It is reduced form of siliqua.

Eg. Candytuft (iberis amara), Capsella

CAPSULE-Dehiscence occurs by various methods. Poricidal (Porous), loculicidal, septifragal, septicidal.

Eg Papaver (poppy-opium plant), Gossypium (cotton), Datura, Abelmoschus (lady finger), onion

SCHIZOCARPIC FRUITS - SPLITTING FRUITS : After ripening, they break/split and divide into mericarps and after destruction of pericarp seed comes out: Each mericarp contains one or two seed (usually one seed).

Schizocarpic fruits are of five types:

LOMENTUM : These fruits are splitted in one seeded many mericarps, after maturity mericarps get separated with each other. Eg Tamarind, Cassia fistula, Mimosa pudica, Arachis hypogea (ground nut/ pea nut), Desmodium, Acacia (babool).

CREMOCARP . It is generally found in umbelliferae family. On maturation, it splits from apex to the base in such a way that two mericarps are formed and catch mericarp contains one seed. These mericarp are attached with carpophore. Carpophore is the extended part of thalamus. Eg Coriander (dhania), Daucus (carrot), Cuminum (jeera = cumin), Foeniculum (saunf-fennel)

REGMA : In it 3 to 5 locules are present and it breaks/splits into 3 to 5 one seeded parts.Each part is known as coccus. At the outer side of pericarp, spines are found. Eg, Euphorbiaceae family (arand-castor Ricinus) has three cocci and Geranium has 5 coccus.

CARCERULUS It divides into four one seeded mericarps / locules & spines are absent. Eg Ocimum tulsi). Salvia

AGGREGATE FRUITS

These fruits develop from multicarpellary, apocarpous gynoecium. In apocarpous condition each carpel is free from each other and it forms a fruitlet. Aggregate fruits are made up of a bunch of fruitlets which is known as etaerio.

Etaerio of achenes In this type of aggregate fruit, each fruitlet is an achene. Eg. Rananculus, strawberry rose, lotus.

In lotus, thalamus becomes spongy and some achenes are embedded in it. In strawberry, thalamus is fleshy and small achenes are found on its surface. In rose, many achenes are present on a saucer (cup) like inner surface of fleshy thalamus.

Etaerio of berries. It is an aggregation of small berries. Eg. Polyalthia, Annona squamosa (custard apple-sitaphal). In etaerio of Anona all the berries are arranged densly on thalamus.

Etaerio of drupes : In this type of fruit, many small drupes develop from different carpels. Eg. Raspberry, blackberry

COMPOSITE FRUITS

All composite fruits are false fruits.

In composite fruits, generally whole inflorescence is modify into fruit. These are of two types 

SOROSIS: This fruit develops from spike, spadix or catkin inflorescence.Eg. Pineapple (annanas) jack fruit (kathal). mulberry (shahtoot)

SYCONUS OR SYCONIUM This fruit develops from hypanthodium inflorescence. Many achene develop from the pistillate flowers. Eg Ficus species like Fig anjeer (Ficus carica), peepal (Ficus religiosa).

Dispersal of fruits and seeds :

We know that most of the plants do not move from one place to another. They grow, produce flower and fruits while remaining fixed at one and the same place. The seeds falling directly under the mother plant have to germinate and develop under limited food supply and space. To overcome this problem, the fruits and seeds have developed several special devices for wide dispersal. The natural agents like wind, water and animals and even mechanism of dehiscence in some fruits, help the seeds and fruits to disperse from one place to another, and to long distances from the parent plant.

Wind -In the species where the seeds are light in weight or have some accessory part to help dissemination, are dispersed by the air current. The seeds of Drum-stick and Cinchona, and fruits of yam, maple and sal tree, are provided with one or more appendages in the form of thin, flat and membranous wings, which help them to float in the air and be carried away to long distances. In the members of Asteraceae, the calyx is modified into hair-like structures called pappus. They persist in fruit and open out like umbrella, helping the seeds to float in the air. In poppy and prickly poppy (Argemone), the fruit dehisces and seeds are thrown out to a distances away from the parent plant. The seeds of Calotropis. Alstonia and cotton are provided with hair and cover sufficient distances alongwith the wind. The seeds of orchids and some grasses are very small and light in weight and may be easily carried away by wind to far off places.

Water -The fruits and seeds with specialised devices which may be in the form of spongy and fibrous outer walls as in coconut and spongy thalamus as in lotus, and small seeds with airy aril as in water lily. float very easily in water and are carried away to long distances with the water current.

Animals -The fruits and seeds with hooks, spines, bristles, stiff hair etc., get attached to the body of hairy and woolly animals and are carried away by them to distant places. For instance fruits of Xanthium and Urena bear curved hooks, spear grass has a bunch of stiff hair, Tribulus has sharp and rigid spines Boerhaavia has sticky hair, which help their dispersal by animals. The edible fruits like guava, grape, fig and phum are dispersed by birds and even human beings, either by feeding on them and passing out undigested seeds with faeces or by carrying them to other places for later feeding.

Defense mechanism in plants :

Plants have developed special organs or devices to repulse or avoid the attack of their enemies. Some plants Hke lemon, pomegranate and Duranta have thorns : pineapple, date palm, Agave and Yucca have sharp pointed spines at the leaf ends, silk.cotton tree and rose have prickles Opuntia and other cacti have spines for their protection from animals. The stinging hair with sharp and siliceous apex occur on all parts of the body in nettles (Laportea spp) and Urtica dioica. Glandular hair with sticky substances are present in jatropha, Boerhaavia and tobacco. The dense coating of hair or stiff hair which are always repulsive to animals are found in cudweed (Gnaphalium) and in many cucurbits.

There are other defense devices like the presence of poisonous and irritating substances in the plants. These are in the form of latex in Ficus. Nerium and Euphorbia alkaloids in poppy, Datura and tobacco, and irritating substances in Colocasia and other aroids. The plants of neem and karela have a bitter taste. Production of tannin, resin, essential oils, etc., in some plants and the geophilous habit in others leg zinger, turmeric, colocasia and onion) are protective measures Some plants like guava, mange and litchi have a habit of harbouring ants (myrmecophily), which save the plant from damage by other animals. Mimicry is a habit of imitating the general appearance, colour, shape of other plants or animals, generally disliked by attackers. The aroids (Caladium) and Sansevieria resemble spotted snakes and are thus able to scare away plant-eating animals