It is interesting to note that the ornamental grasses belong to several families depending on their characteristics. These families include true grasses, the sedge family, the restio family, the rush family and the cat-tail family. A brief account of each of these ornamental grass families is discussed below.
This is one of the largest families of ornamental grasses comprising about 650 genera and approximately 10,000 species, most of which are common plant varieties. It may be noted that lawn grasses, cereals as well as bamboo and others belong to this grass family. There are many prominent species of the true grasses and some of them are the fountain grass (Pennisetum), fescues (Festuca), pampas grass (Cortaderia), Chinese silver grass (Miscanthus) and switch grass (Panicum).
According to the botanists, the grass stems are known as culms, which are rotund and generally hollow. These culms are different from the stems or culms of sedges. Typically, the culms of sedges are firm and usually three-sided. There are growths called nodes at regular intervals along the length of culms and these are the points from which new grass leaves come out. Such nodes are contrary to the other flowering plants, as the tips of the stems are the growing points of the latter type of plants. Often, the grass leaves provide shelter to the nodes by means of covering the stems or culms under them and also by developing filaments akin to shields over them.
The form of their flower heads or the inflorescences were more typical of the individual ornamental grass species of this family. Grasses belonging to this family are pollinated by the wind and, therefore, they neither have nor need attractive blossoms, which are a major attribute of the plants that are pollinated by insects. While the real flowers of the true grass family are diminutive, they usually occur copiously. When gathered collectively, these tiny flowers form spikelets - that are denoted as inflorescences when complemented as one.
It may be noted that the general look of the flowering grasses depends on the display of these spikelets and this is vital while describing as well as classifying them. Basically, the spikelets are structured in three dissimilar forms - the spike is branchless, extended inflorescence with the spikes being directly connected to the main stem or axis of the flowering head, leading to a firm, slender arrangement; the panicle is the extremely subtle among the three arrangements having its spikelets extended to the branches; and the raceme is a rather slacking structure having the spikelets growing sideways from the axis or the main flowering stem.
Compared to the ornamental grasses, the sedges family is smaller. Nevertheless, still the sedges continue to be a big family of about 115 genera and as many as 3600 species - almost 50 per cent of these are perennially growing. It is worth mentioning here that the botanical name of the sedges family has been drawn from the genus Cyperus. Similar to grasses, sedges are also a broad-based collection. You may find sedges growing in most of the regions of the world, but they are particularly widespread in damp or humid environments in the temperate as well as the sub-arctic regions, wherein they perform a vital function in stabilizing the soil. Majority of the sedges have a preference for sunlight. However, there are several other species that are indigenous to the out of the sun forested habitats.
As far the food sources of humans or even domesticated animals are concerned, sedges are insignificant. Nevertheless, a number of sedges are edible, while there are many others that are used for commercial purposes. For instance, the Chinese water chestnut (botanical name Eleocharis dulcis) is especially grown for the plant's tubular stems, like in the instance of earth-almond or chufa (botanical name Cyperus esculentus var. sativus). On the other hand, people used the stems of the papyrus or Egyptian paper-reed (Cyperus papyrus) in the form of a raw material to manufacture papyrus paper of traditional antique. In addition, several other varieties of sedges, including the bulrush (Schoenoplectus tabernaemontani) are employed to make baskets, weave mats as well as making seats of chairs. Moreover, galingale (Cyperus longus) yields aromatic oils that are used in the perfumery industry. Another variety of sedges called cotton grass belonging to the Eriophorum species, have feathery heads that are used in stuffing pillows.
In addition to having fibrous roots, majority of the sedges species also have rhizomes or stolons which give rise to new plants. A number of sedges have tufted growth, while there are other species that take the shape of spreading mats. In fact, it is possible to distinguish the sedges from the ornamental grasses by means of the numerous different features of their leaf and stem. Sedges have stems that are firmly packed with pith and lack nodes and, more often than not, they have a triangular cross-section. The leaves of the sedges are positioned in three rows, and their covers are generally merged about the stem. The leaf blades of sedges are akin to those of the ornamental grasses; however, they do not have ligules. Even if they have ligules, they are very condensed. Several varieties of sedges have foliage that is evergreen or partially evergreen. Their color varies from green to blue, almost yellow and reddish brown. The leaves of several varieties of sedges that are cultivated are spectacularly multi-colored.
Like grasses, sedges are also pollinated by wind. The individual flowers of this variety of plants are usually not easily seen, lacking identifiable petals or sepals. The flowers of sedges are clustered in spikelets frequently, but not all the times. The spikelets or flowers of sedges may possibly set in a variety of umbels, spikes or panicles. However, unlike grasses, sedges are never found to be developing the large exposed panicles, or crowded panicles akin to plumes. Often, you may find abridged bracts or leaves at the base of the inflorescences produced by sedges. In the instance of the genus Rhynchospora, such bracts are delightfully covered white.
A number of members belonging to the sedges family produce bisexual blooms, while several others, counting the big genus Carex, bear male as well as female flowers clustered in individual spikes inside the inflorescence of the same plant. Normally, the female flowers of the genus Carex are contained in a structure akin to a sac and are known as utricle or perigynium. These formations are puffy and remarkably striking in the species called Gray's sedge (botanical name C. grayi). A number of sedges have almost black hued flowers, for instance, C. nudata, while the species C. baccans bears strictly red blooms. Nevertheless, the blooms as well as the inflorescences of majority varieties of sedges have delicately green and off-white hues. Needless to say, these varieties of sedges seldom create the spectacular shining effects that are caused by true grasses.
While you can find rushes growing all over the world, they are a reasonably petite family comprising just 10 genera and below 400 species. Majority of the rushes are perennially growing herbs that are mostly found in moist or damp environments in places having cool temperate as well as sub-arctic climatic conditions. Annually growing species of rushes are very rare. In the form of a source of fibers as well as fastening material, the rush family is of trivial significance commercially. An exception to this is Prionium, the sole shrub-like genus in this family, which comprises palmiet (P. palmitum) of South African origin. The leaves of this rush species are known to be a resource of a sturdy fiber known as palmite. On the other hand, the sea rush (botanical name Juncus maritimus) is a natural resource of the fastening material called juncio, while the common or soft rush stems known as J. effusus are utilized in basket making, producing seats of chairs as well as a variety of mats, counting the Japanese tatami.
More often than not, herb-like rushes that grow perennially have bristly roots, while the rhizomes are either vertical or horizontal. The stems of these plants are upright, tubular as well as dense. Typically the leaves of perennial herbaceous rushes are basal and, occasionally, abridged to just coverings. Similar to ornamental grasses and sedges, rushes are pollinated by wind and their blossoms are somewhat diminutive, and have delicate hues. Generally, the color of the flowers varies - either green, near-black or brown. However, sometimes the flowers may also be found in white or beige-yellow hues. Despite being tiny, the flowers of rushes have a close underlying similarity with the flowers of lily - with six analogous tepals organized in two whorls. Majority of the rushes bear bisexual flowers, each flower having six stamens and one ovary having three stigmas. On the other hand, there are a number of species of rushes bearing male and female flowers on individual plants. The copious diminutive flowers borne by the rushes are put together in panicles, corymbs or bunched heads.
Among the 10 genera of rushes, just two are fundamental to ornate horticulture. These genera include Juncus (the rushes) and Luzula (the woodrushes), both perennially growing plants. It may be noted that the rushes have a preference for a damp and sunlit environment and they have a propensity to blossom during the summer. In general, the leaves of rushes emerge from the crown or the clump, and are tubular bearing a resemblance to the stems. Luzula or the woodrushes are indigenous to damp or arid shaded environments and bear flowers either in spring or during early summer. More often than not, rushes are evergreen plants and their leaves are typically basal. However, the leaf blades are even, generally having noticeably hairy edges.
The restio family of plants is comparatively lesser known to the gardening fraternity and its cultivation is just about completely confined to the southern hemisphere, especially in the countries of its origin, such as Australia, New Zealand, Tasmania, Malaysia, Southeast Asia, Africa, Madagascar and Chile. The restio family is fairly large and comprises about 38 genera and over 400 species - all of which are perennially growing plants. Among the over 400 species of plants in this family, a minimum of 300 are indigenous to southern Africa's Cape floral region. The climatic conditions in the Cape floral region are similar to that prevailing in the Mediterranean region - with the winters being cool and moist and summers are hot and arid. In general, the soil is covered in dust and has very low nutrient content. The typical vegetation of the Cape floral region includes a delicate scrub known as fynbos. In this region, the plants belonging to the restio family frequently substitute the true grasses.
Restios are intimately associated with the rushes and in general also look like rushes. However, some restio species posses stems that are highly branched and also have a strong similarity to horsetails externally. The restios vary in height from approximately 8 inches (20 cm) to over 10 feet (3 meters). It is seldom that plants belonging to the restio family grow leaf blades that are purposeful. Instead of the leaves, the green stems of these plants carry out photosynthesis. Typically, the stems of restios are either dense or hollow and, more often than not, have prominent nodes. Often the leaf sheaths of restios occur at the nodes and usually have a tan, cinnamon-brown or even golden hue. From the gardening point of view, these leaf sheaths are extremely ornate. Several species of restios have tufted growth, while others are tussock-forming. Many other restios species also have sluggishly crawling rhizomes.
The roots of the plants belonging to the restio family may possibly be plump or slender and sinewy. Restios bear small individual flowers that are unisexual in nature and mostly pollinated by wind. The male and female flowers appear on separate restio plants. The flowers of restio are green or brown hued and are normally clustered in spikelets, which consecutively form floppy inflorescences. Every spikelet of restios is contained partially by a brown or amber hued bract that is noticeable and bearing resemblance to a sheath. It is interesting to note that the male and female restio plants belonging to the same species frequently have dissimilar appearances, which makes it quite difficult to identify as well as classify the plants in this family compared to others.
In the form of a food source, plants belonging to the restio family are of little commercial significance. Nevertheless, a small number of restio species have been employed for long for thatching purpose. For instance, roofs thatched using the restio species Thamnochortus insignis are known as dakriet in South Africa and these may well endure for over 20 years. In fact, a rejuvenated awareness regarding traditional architecture in South Africa has actually resulted in a booming thatching industry in the country. Several members of the restio family produce attractive stems as well as seed heads and these also form a significant aspect in the global cut-flower business.
Several restio varieties have immense decorative demand, often challenging the elegant radiance of the true grasses. While very few species of restios have the aptitude to endure the cold winters, especially in places having cold temperate climatic conditions, they possess immense ornate potentials for gardens all over the world, especially places having the Mediterranean climatic conditions, and also in the form of themes of warm-season container show or glasshouse. In effect, in recent times, the restios have not been familiar in horticultural circles primarily owing to the problems encountered in propagating these plants. Since restios loath propagation by root division, it is best to spread this family of plants by means of their seeds. Nevertheless, the rate of germination of most of the plants belonging to the restio family is extremely poor under regular conditions and when standard means are utilized.
The family of ornamental grasses called cat-tail is a minor one, consisting of just one genus called Typha, which comprised less than 15 species. Nevertheless, this family of ornamental plants usually stands in for freshwater habitation all over the world. Cat-tails are herb-like perennial plants that have a preference for low water and grow up to a height of 8 feet (2.4 meters). Plants belonging to this family multiply by means of their rhizome giving rise to vast colonies in ponds, marshes and also along the banks of lakes and rivers. They are useful for wetland birds, as these plants provide them with materials for making nests.
Ornamental grasses belonging to the cat-tail family do not have much commercial significance. Nevertheless, the fully grown leaves of these plants have been employed to make mats, caning, and thatching. Cat-tails have chunky rhizomes that are safe for consumption. As they have rich starch content, the cat-tails are a possible source of food for humans. The indigenous people have employed the feathery seed-heads of the grasses belonging to the cat-tail family in the form of an alternative for feathers. It is worth mentioning here that the importance of the plants in the cat-tail family in the form of cleaning agents in the contaminated marshland regions is growing gradually.