Symbiosis

Symbiosis, the habitual living together of organisms of different species. The term is usually restricted to a dependent relationship that is beneficial to both participants (also called mutualism) but may be extended to include parasitism, in which the parasite depends upon and is injurious to its host; commensalism, an independent and mutually beneficial relationship; and helotism, a master-slave relationship found among social animals (e.g., the ant and the aphid). True symbiosis is illustrated by the relationship of herbivorous animals (e.g., cockroaches, termites, cows, and rabbits) to the cellulose-digesting protozoans or bacteria that live in their intestines; neither organism could survive without the other. Other symbiotic relationships include the interdependence of the alga and the fungus that form a lichen and the relationship between leguminous plants and the nitrogen-fixing bacteria, which is important in agriculture. Two obvious examples of a plant-to-animal relationship are yucca and yucca moth, fig and fig wasp; in both cases the insect fertilizes the plant, and the plant supplies food for the larvae of the insect.

Peat Moss

Peat Moss, also called sphagnum moss and bog moss, common name for about 300 species of moss plants that grow in swamps and bogs throughout the world. Peat moss may grow to 30 cm (12 in) or more in height. The plants have many branches covered with small, light green leaves. The leaves and stems have special cells that absorb and hold much water.

Peat moss is one of the most common plants from which peat, a fuel, is produced. When the plants die, the dead organic matter is preserved more or less intact because the moss is acidic, so bacterial and fungal decay occurs slowly. The dead peat moss and other plants are compressed by the weight of the living plants growing above them. This compressed matter eventually forms the peat. The peat can be cut into blocks and removed for use as fuel. Peat moss is also useful in gardening. It combats excessive alkalinity in the soil and produces the acid environment that certain plants need to grow, including such ornamental shrubs as rhododendrons. Its absorptive characteristics make peat moss useful as a packing material for shipping plants.

Scientific classification: Peat mosses are members of the family Sphagnaceae. They belong to the genus Sphagnum.

Moss Growing on a Tree Trunk
There are over 14,000 species of primitive plants called mosses belonging to the phylum Bryophyta. Most species are terrestrial and, although requiring abundant moisture, are highly adaptable, living on rocks, tree trunks, stumps, wooden buildings, and asphalt roofing shingles. Several species are adapted for life in bogs, swamps, and streams.


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Hornworts

A small bryophyte plants belonging to the phylum Anthocerophyta; any of several submerged plants of the genus Ceratophyllum, forming branched masses in quiet water and having finely dissected, whorled leaves and minute unisexual flowers. 

Unlike liverworts but like mosses, hornwort sporophytes have stomata. The hornwort gametophyte consists of a low thallus, out of which numerous slender, upright sporophytes tipped with sporangia grow. The sporophyte has a meristem that elongates the sporophyte with new growth, a feature that distinguishes the plant from the other bryophytes. The name of the hornworts was suggested by the hornlike appearance of the sporophytes.

Calabash Tree

Calabash Tree (Crescentia cujete) of the trumpet-creeper family (Bignoniaceae), 6 to 12 metres (20 to 40 feet) tall, that grows in Central and South America, the West Indies, and extreme southern Florida. It is often grown as an ornamental. It produces large spherical fruits, up to 50 cm (20 inches) in diameter, the hard shells of which are useful as bowls, cups, and other water containers when hollowed out. The fruit's shell encloses a whitish pulp and thin, dark brown seeds. The tree bears funnel-shaped, light green and purple-streaked flowers and evergreen leaves. Fruits of the unrelated bottle gourd (Lagenaria siceraria) are also known as calabashes. In some countries the rind and juice are used for medicinal purposes.

Rye

Rye, cereal grain of the family Gramineae (grass family). The grain, Secale cereale, is important chiefly in Central and N Europe. It seems to have been domesticated later than wheat and other staple grains; cultivated rye is quite similar to the wild forms and no traces of it have been found among Egyptian ruins or Swiss lake dwellings. Where it grows well, wheat is preferred, but rye will produce a good crop on soil too poor or in a climate too cool to produce a good crop of wheat. The standard schwarzbrot, or pumpernickel, of Europe was formerly the major rye product. A bread of lighter color, called rye bread, is made of rye flour mixed with wheat flour. Today rye is used mostly as a stock feed (usually mixed with other grains), for hay and pasturage, for green manure, and as a cover crop. Russia leads in world production. Rye is much used as a distillers' grain in making whisky and gin. The tough straw of rye is valued for many purposes, e.g., thatching for roofs and stuffing for horse collars. Ergot is a fungus disease of rye; the fungus is poisonous and may make the rye unsafe to use. Wild rye and lyme grass are names for several grasses of the genus Elymus, some of which are occasionally planted as ornamentals or used for binding sand. Rye is classified in the division Magnoliophyta, class Liliatae, order Cyperales, family Gramineae.

Shadbush

Shadbush, Juneberry, or serviceberry, any species of the genus Amelanchier of the family Rosaceae (rose family), chiefly North American shrubs or trees conspicuous in the early spring for their white blossoms. The bush is more often called shadbush on the East Coast (it is said to bloom when the shad are running); serviceberry is in general a Western name. The huckleberrylike fruits of native species were eaten by the Native Americans and are still sometimes collected. They are an important wildlife food. Some kinds of shadbush are cultivated for ornament. The wood is very hard. Shadbushes are classified in the division Magnoliophyta, class Magnoliopsida, order Rosales, family Rosaceae.

Cinquefoil

Cinquefoil (sĭngk`foil) [O.Fr.,=five leaves], name for any plant of the widely distributed genus Potentilla of the family Rosaceae (rose family), chiefly herbs of north temperate and subarctic regions. Most cinquefoils are perennial; many but not all of them have leaves of five leaflets, for which they are also called five-finger. The flowers are most often yellow. Most North American species are native to cooler regions of the W United States. The shrubby cinquefoil (P. fruticosa) and the silverweed (P. anserina) are common wildflowers in the West and the Northeast; they are thought to be naturalized from the Old World. These and other species are sometimes cultivated in rock gardens. Silverweed is one of the species reputed to have medicinal powers, hence the Latin name of the genus [potens=powerful]. Cinquefoil is classified in the division Magnoliophyta, class Magnoliopsida, order Rosales, family Rosaceae.