Plants are typically grouped into families based on similarities in their structures. The type and organization of the flower parts are often key traits by which plant families may be determined. Thus, botanists, have come up with a scheme for representing the flower structure of the various families.
1. Before writing about any family start with the habitat of the plant. It should be noted whether it is a herb, a shurb or a tree. 2. After the reference to its lifeform, its lifespan should be mentioned, i.e. whether it is an annual, a biennial or a perrenial plant. 3. Its natural lifestyle, such as whether it is a mesophyte, a hydrophyte or a xerophyte, should be noted. 4. Then the specific characters, regarding its rootsystem, stem and leaves should be noted. 5. The kind of inflorescence, constitution of components of various floral whorls, the kind of flower, etc. should be noted in proper sequence. After noting down various characters as above, a floral formula and a floral diagram are constructed on their basis
Floral formula In construction of the floral formula, the number of members in the floral whorls, their union with one another, their insertion on thalamus, their association with other whorls, etc. are taken into account. Various symbols used in a floral formula and their meanings can be explained as under :
1. If the members are united with one another, this number is written in brackets (), other wise, it is written without them, e.g. K 5 means five free sepals in calyx and K(5) means five united sepals in calyx. 2. If the members of one whorl are associated with the members of another whorl, a horizontal connecting line is drawn over the two whorls. For example, C 5 A 7 indicates attachment of stamens with petals. 3. If the members in a whorl are arranged in one or more groups, the members of groups are indicated as a sum. For example, A (9) +1 means two groups of stamens. 4. The position of ovary of gynoecium is indicated as under G = inferior ovary. G = superior ovary. The floral formula of Datura is given below as an illustration.
Important characters of the family- 1. The plant belongs to this family have a charcterstic smell of sulphur which is due to the enzyme myrosin present in the plant cell. 2. Flower arrangement is usually typically Raceme. 3. In this family the flower use to devlope again and again and there is no flower at the tip. 4. Examples are-Napiform roots-turnip Fusiform roots-radish Cabbage,cauliflower,mustard etc.
Floral formula of cruciferae family
1.Food –radish,turnip,mustard,cabbage,cauliflower 2.Medicines-halima-in liver disorders. Wall flower-used in fever and cough. Tarha-in asthma. Chandani-in rheumotoid arthrithis. 3. For ornamental purpose- Chandani,wall flower
Special charcterstics- Plancenta where ovary is placed is swollen. So ovary is placed at one side. Only in tomato and datura ovary is polyocular. In this family all parts of fruit are eatable. Examples are-potato,tomato,capsicum,datura etc.
Special charcterstics- Ovary is perigynous G- and monocarpellary Placenta is marginal This family is further divided into three sub families depending upon the difference in there charcterstics of corolla(C) and androceium(A) Papilionatate Caesalpinoideae Mimosoideae
Papilionatae special charcters- Tap root system is present in the plant. Rhizobium nodoules is present in the roots. Nitrozen fixation bacteria is present in the roots of the plant. Examples- food - pea,gram(channa),dal(udad,masar,moong),soyabeen, french bean(razma),indian rose wood,red sandaletca. Dyes –indigofera tinctoria,butea monosperma Medicinal-liquorice(cough and cold),kameria trianda(for diarohea) Other uses-insecticidal,gum, timber industry
Special charcterstics- Flower arrangement-penicle and each branch is raceme. Tap root system. Examples-food- imli(tamarindus indica),kanchnar Ornamental-ashoka,gulmohar Timber-brazil wood,purple heart wood Medicines-ashoka-female disorders Amaltash-laxatative property
Special charcters- Stipule are in the form of spines Most of the plant are xerophytes. Two type of flower arrangement-capitate and spike. Examples-timber-mimosa tree,acacia arabic(babul) Ornamental plant-touch me not,hedge plant
Roots are adventitious or either fibrous. Stem can be aerial or underground. It is difficult to differntiate between calyx(k) and corolla so perianth(p) is present. In this stem changes into fleshy leaves. Examples-food- onion,garlic. Medicines-Aloe vera,sudharsan powder,garlic. Ornamental-tulip, lily
Special charcters- It is also having perianth. Flower arragement(infloresecense)- spike or penicle. Leaves are alternate Examples-ornamental –cyanodon dactylon(doob) Cereals-rice,bajra,triticum astivum(gehu),zea mays. Other uses-fibers,paper industry,medicinal plants,timber.
Special characters-. The leaves are simple, usually opposite and decussate, or whorled; stipules are usually absent. The flowers are bisexual and actinomorphic or sometimes weakly zygomorphic. Ovary superior sometimes partially inferior. Examples-rauwolfia,kurchi,devil tree etc.
Special features- Infloresence: Solitary, Cymes, Racemes Ovary: Superior Leaves: Simple or Pinnate. Examples-citrus fruits-lemon,orange Wood apple etc.
Floral Symmetry: Radial Ovary: Inferior (rarely Half Inferior or Superior). Infloresence: Cymes, Head, Panicle Leaves: Simple Examples cinchona,ipeac etc.