Tag: botany

Fossils are the remains of living creatures, both plants, and animals, or their tracks. These are found in sedimentary rock. Sedimentary rock is composed of strata. The term rock strata refer to stacked-up layers of sedimentary rock. Other kinds of rocks can have layering in them, but the word strata are reserved for sedimentary rocks - rocks composed of individual fragments of minerals or other rocks. 

On the basis of fowers and inflorescence the most advanced family in angiosperms is Asteraceae. Asteraceae are mostly herbaceous plants, but some shrubs, trees and climbers do exist. Asteraceae are generally easy to distinguish from other plants, mainly because of their characteristic inflorescence and other shared characteristics. The Asteraceae commonly referred to as or sunflower family are an exceedingly large and widespread family of Angiospermae. The name Asteraceae comes from Aster, the most prominent genus in the family, that means star, and is connected with its inflorescence star form. As for the term Compositae, more ancient but still valid, it obviously makes reference to the fact that the family is one of the few angiosperm ones to have composite flowers. This family has a remarkable ecological and economical importance. The Asteraceae may represent as much as 10% of autochthonous flora in many regions of the world. Most members of Asteraceae are herbaceous,but a significant number are also shrubs, vines, or trees. The family has a  worldwide distribution and is most common in the arid and semiarid regions of subtropical and lower temperate latitudes. The Asteraceae are an economically important family.

A family which was named after its inflorescence is Apiaceae (umbelliferae). The defining characteristic of this family is the inflorescence: a simple or compound umbel. Flowers across the Apiaceae are fairly uniform and are usually perfect hermaphroditic and actinomorphic, but some are andromonoecious, polygamomonoecious, or even dioecious, with a distinct calyx and corolla, but the calyx if often highly reduced, to the point of being undetectable in many species, while the corolla can be white, yellow, pink or purple. The flowers are nearly perfectly entamerous, with 5 petals, sepals, and stamens. The androecium contains of 5 stamens, but there is often variation in the functionality of the stamens even within a single inflorescence. Some flowers are functionally staminate while others are functionally pistillate.

Anthodium inflorescence is characteristic of sunflower. Sunflower belongs to Asteraceae.The genus is one of many in the Asteraceae that are known as sunflowers. It is distinguished technically by the fact that the ray flowers, when present, are sterile, and by the presence on the disk flowers of a pappus that is of two awn-like scales that are cauducous. They bear one or
several to many wide, terminal capitula (flower heads), with bright yellow ray florets at the outside and yellow or maroon disc florets inside. Several
ornamental cultivars have red-colored ray florets. Indeterminate simple inflorescences are generally called as racemose anthodium inflorescence. The main kind of racemose inflorescence is the raceme  and the other kind of racemose inflorescences can all be derived from this one by dilation, compression, swelling or reduction of the different axes.

The peduncle is compressed to a flattened or convex disc, the receptacle and the flowers (florets) are sessile this represents capitulum inflorescence. A flower head or capitulum is a very contracted raceme in which the single sessile flowers share are borne on an enlarged stem. Capitulum can be used as an exact synonym for pseudanthium and flower head, however its use is generally but not always restricted to the Asteraceae family. At least one source defines it as a small flower head. Flower head is a special type of inflorescence  in which anything from a small cluster to hundreds or sometimes thousands of flowers are grouped together to form a single flower-like structure. Pseudanthia take various forms. The individual flowers of a pseudanthium commonly are called as florets.

An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Determinate simple inflorescences are generally called as cymose. The main kind of cymose inflorescence is the cyme. The cyme is refered as dichasial when there are two secondary axis. If in an inflorescence two lateral branches develop on either side of the terminal lower which again branch is known as dichasial cyme. Dianthus  species are mostly herbaceous perennials  and some are low subshrubs with oody basal stems. The leaves are opposite, simple, mostly linear and often strongly glaucous grey-green to blue-green. The flowers have five petals, with dichasial cyme.

Flowers of Poaceae are characteristically arranged in spikelets, each spikelet having one or more florets. The spikelets are further grouped into panicles or spikes. A spikelet consists of two or sometimes fewer bracts at the base, called as glumes, followed by one or more florets. A floret consists of the flower surrounded by two bracts, one external the lemma and one internal the palea. The flowers are usually hermaphroditic maize being an important exception and anemophilous or wind-pollinated. The perianth is reduced to two scales, called as lodicules, that expand and contract to spread the lemma and palea. These are generally interpreted to be modified sepals. The lodicules are the two diminutive bodies lying between the lemma and the ovary base in the grass floret which, by expanding rapidly at the time of anthesis, lever away the rigid lemma allowing anthers and stigmas to emerge. Expansion results from the swelling of a cushion of tissue at the base of each lodicule. Perianth of Gramineae are not termed as tepal, ligule and spur. 
Therefore, the correct answer is option C.

Depending upon the mode of branching of peduncle, the inflorescences are of two main types - Recaulescent and Concaulescent.
When the bract is attached to the stem holding the flower (the pedicel or
peduncle), it is said to be recaulescent; sometimes these bracts or bracteolesare highly modified and appear to be appendages of the flower calyx. 
Recaulescences is the fusion of the subtending leaf with the stem holding the bud or the bud itself, thus the leaf or bract is adnate to the stem of flower. When the formation of the bud is shifted up the stem distinctly above the subtending leaf, it is described as concaulescent.

Unisexual flowers are present in Morus, Ficus and Poinsettia. A unisexual flower is one that has stamens but no pistils or having pistils but no stamens. A flower having only stamens is said to be staminate, or male. A flower having only pistils is said to be pistillate, or female. In many unisexual flowers, the nonfunctioning organs of the other sex are present in reduced form, thus attesting to the plants original bisexual nature. Such flowers are said to be functionally male or functionally female.

Brassica oleracea var. capitata, the common name is cabbage. Cabbage is a typical cool season crop grown for the thickened vegetative bud called as head. It is one of the most  popular and widely grown vegetables and has occupied second position in production after potato. It is a rich source of vitamin A, C and mineral including potassium, calcium, sodium and iron.