BLUE-GRASS. Poa pratensis. The genus poa is one of the most important of the family of grasses, being decidedly the most valuable of our pasture grasses in soil suited to it. Upon rich, open, argillaceous soils, containing lime, and upon rich dry limestone soils proper, it is entirely at home, furnishing an abundance of early and late pastures, and south of the latitude of 40° north, and thence south it furnishes much valuable winter pasture. In Kentucky, the Blue-grass region has become famous, the world over. The profusion of nutritious, radical leaves constitute the superior excellence of this grass. It is also known as Spear-grass, Green-grass, and Smooth Meadow-grass. It is a perennial creeping rooted grass, smooth-stemed, flowering in May and June, according to the latitude, and ripening a month later. In poor soils it soon deteriorates and is of little value. Poa eompressa, to which the name of Blue-grass might more properly be applied, is also known as Blue-grass in some por tions of the North, also as Wire-grass and Flat stalked Meadow-grass. This also is a perennial creeping rooted grass, the plant smooth, but with short and fewer radical leaves than the so called . Kentucky Blue-grass. It has found its way into most pastures in the North, and if less flush, certainly is as rich or richer pasturage than Poa pratensis. Both species are said to have been introduced, but if so, they have taken kindly to their adopted home, and have proved most valuable wherever acclimated. The cut shows the Kentucky Blue-grass (Poa eompressa.) Kentucky Blue-grass is chiefly distinguished by the woolly web at the base of the floret, and the hairs on the lateral nerves of palea; the inner pales is a very little shorter than the outer, and is occasionally bifid at the summit. The culms are generally smooth, as are the sheaths, but they are occasionally a little rough; the upper sheath is much longer than its leaf. It is indigenous in all the Northern States, gen erally found on calcareous soil. The following from various authentic sources, will give an idea of the value of this grass, and of the general estimation in which it is held. No grass varies so much from alterations of soil and climate and exposure, as this. The flowers are sometimes tumid and tinged with red; under other circum stances, they are a pale green, and compressed. The culms and leaves are sometimes a dark blu ish g:reen; soinetimes of a pale yellowish green; sometimes one foot high, and at others over three feet. British authors enumerate six or seven sub-varieties of it, with a view of classifying these differences; we have representatives of most of them in this country. This great differ ence of habit causes a very different value to be assigned to it in different sections of the country. Thus, Mr. Klippart says, that it is very much in favor in Southern Ohio, whilst in Northern and Northeastern Ohio it is considered a very unwel come guest in the grass lands. A Kentucky farmer, quoted by Mr. Flint, says of it: In our climate it is not only the most beautiful of grasses, but the most valuable of crops. It is the first deciduous plant which puts forth its leaves here, ripens its seeds about the 10th of June, and then remains green, if the summer is favorable in moisture, growing slowly till about the last of August, when it takes a second vigorous grovvth until the ground is froen by winter's cold. If the summer is dry, it 'dries up utterly, and will burn if set on fire, but even then, if the spring growth has been left upon the ground, it is very nutritious to all grazing stock, and especially to sheep and cattle and all ruminating animals. When left to have all its fall growth, it makes fine winter pastures for all kinds of grazing animals. Cattle will not seek it through the snow, but sheep, mules and horses will paw it off 'and get plenty without any other food. When cov ered with snow, cattle require some other feeding; otherwise, they do well all winter upon it. It makes also the best hay. I have used it for twenty years. It should be cut just as the seeds begin to ripen, well spread and protected from the dew at night. When properly cured, stock seem greatly to prefer it to all other hay. Thus much for the Kentucky farmer, who testifies that it is about as good as any grass can be. Dr. *Darlington tells us, in his Agricnitural Botany, that it is, indeed, as Muhlenberg terms it, opti mum pabulum, being decidedly the most valuable of all the grasses known to our pastures. Prof. Buckman, of the Royal Agricultural College at Cirencester, says that it yields a good bulk for the rick, and sends up a quantity of herbage for the aftermath, whieh is less injured by the cold and other elimatie changes than almost any other species. We have extracted these widely differ ing opinions respecting this grass, that our readers may see how little is really known about the grasses and how imperfectly our observations of them have been made. This is one of the most widely diffused grasses in the world. We have had the amplest opportunities for observing it, and yet we can come to no agreement upon its merits. Some things about it are admitted upon all hands. It enters into the composition of the best meadows and pastures in Europe and America. The famous pastures of Kentucky, which will fatten animals faster than any other in the known world, are filled with this grass. The fine meadows and pastures of Vennout, on the western slope of the Green mountains, con tain a very large proportion (at least two-thirds) of it. Wherever the sweetest and best keeping butter is made, this grass will occupy a very conspicuous place in the pastures; the best but ter can not bt made where this is wholly missing in the pasture. Although some grasses start earlier in the spring, yet it affords a good bite much earlier than most species. There is no grass known that bears the extreme eold as well as this, even as far north as Vermont; after lying exposed to the eold and snow all vvinter it is eaten greedily by the cattle in the spring, and they are found to thrive upon it; sheep and even horses will paw away the snow in winter and eat the grass beneath with great avidity. It only sends up one flowering culm in a season, and these stand far apart; hence, at the first cutting, the burthen of hay is less than that afforded by several other species, bnt in August there is a _great growth of root leaves which give a heavy bulk at the second cutting; the rowen, which is more abundant than any other, fully makes up for the deficiency of the first crop. In the west, ivvherever it will grow, and in the northern por tion of the Southern States it is the chief reliance for winter pasture. It succeeds in light lands
where fibrous rooted grasses would fail. Its nutritive properties, as given by Mr. Way, are as follows. In one hundred pounds of grass there are 67.14 pounds of water; 3.41 pounds of albuminous or fiesh-forming principles; 0.86 pounds of fatty matters; 14.15 pounds of heat forming principles, such as sugar, gum, etc.; 12.49 pounds of woody fibre, and 1.95 pounds of mineral matter or ash. According to the analyses of Scheven and Ritthausen,Poa pratensis gave for 100 pounds of grass, sixty-two pounds of water, four pounds of albuminous matter, 1.1 pounds of fatty matters, 15,4 pounds of heat producing principles, 15.6 pounds of woody fibre, and 1.8 pounds of ash. The Woburn experiments show the production of an acre to be 10,209 pounds, which lost 7,337 pounds in drying, and gave 279 pounds of nutritive matter. When the seed was ripe, it yielded 8,507 pounds to the acre, which lost 5,104 pounds in clrying, and gave 199 pounds of nutritive matter. The produce of the aftermath was 4,083 pounds to the acre, and yielded 111 pounds of nutritive matter. The discrepancies in these estimates of its nutritive value are undoubtedly due in a great measure to differences in the soil and climate of the places of its growth. We have never seen the cnlms longer than two and a half feet. Its average height in the regions that we are roost acquainted with does not exceed eighteen inches. We have never seen any record of its producing more than three tons of hay to the acre, and have never actually seen a greater yield than one ton to an acre. It is well adapted for irrigation. When irrigated lands are ridged this always oecupies the crowns of the ridges. Its favorite habitat is a limestone soil, which, if not too dry, w ill produce it in the greatest abundance. It is found in positions 3,000 feet above the level of the sea, but its valuable qualities are not mani fested at over half that altitude. The seeds are acuminate or pointed, furrowed on the flat sides, and are furnished with a thick, woolly web, which entangles the seed. It weighs about thir teen pounds to the bushel. With the aid of a glass they may be clearly distinguished from the seeds of P. trinialis, the latter being shorter, rounder and nearly quite fiat on the faee. Dr. Darlington says that it is unnecessary to sow the seed in Pennsylvania if the field is well limed and manured. It will at once take possession of the land and grow vigorously. Hence, in that region the prevalence and the luxuriant growth of this grass is one of the best evidences that the land is in good condition and well managed. In many parts of Illinois, where the prairie is once depastured, although not a spear of this grass was seen before, the whole ground will be cov ered with it, to the complete and the permanent exclusion of the former prairie plants. In poor lands, and in those ill adapted for this grass, its growth is exceedingly dwarfish, and it would hardly be reeognized by a superficial observer a,s belonging to the same species as that which he sees in more favored localities. It is probably owing to this cause that so many contradictory statements have been given with respect to its qualities. The straw of this grass, when bleached, is plaited like leghorn for bonnets, which are quite'equal to the leghorn in beauty, and supeHor in fineness. None of the grasses surpass it in the beauty of its forms and the gracefulness of its movements. Nowhere can we find more fairy like delicacy of structure and contour, more graceful curves of motion, or greater softness and purity of color, than in the expanded panicles of Blue-grass. Poa Compressa is also called Blue grass and Wire-grass. The panicle is somewhat spreading in flowering time, but otherwise con tracted; the branches in pairs or threes, short, flexuous, rough, often one-sided, the lowermost rather remote. Culm much compressed, decum bent, nine to eighteen inches long, usually about a foot long, geniculate at the base. It bears four or five leaves with smooth, striated sheaths. The leaves are smooth, short, linear, keeled, of a dark bluish green color. We know no grass of so dark a color except, perhaps, some specimens of Festuca n uta ns. Upper leaf about equal in length to its sheath. Perennial ; rhizoma creeping, and flowers in June and July. It seems to be the prevalent opinion among botanists that it was introduced from abroad; but in some regions it certainly appears to be indigenous. It is found in dry fields and banks. Frequently it rday be seen growing in the joint,s of slaty rocks. It is also often found in damp clays, which are inter mingled with gravel and small boulders, and it would be difficult to say in which of these soils it flourishes best . It never forms a close turf, and is rarely found intermixed with other grasses. Hence it never yields a great bulk of hay, but this bulk weighs very heavily, so that the hay from an acre will weigh a ton or a ton and a half. We have often cut this amount from land on which a person unacquainted with the grass would not expect to get half a ton. It is certain that cows that feed upon it both in pasture and in hay give more milk and keep in better condi tion than when fed on any other grass. Horses fed on this hay will do as well as when fed on timothy hay and oats combined. This we have verified abundantly. The crops are remarkably even; it rarely suffers from excessive wetness or dryness. Sinclair says that heavy manuring very slightly increases the crop. This differs from our experience. We never, indeed, succeeded in making a thick sod,. but we have by manuring caused the culms to approximate more closely than they did before, and their length has been increased to two feet, while the diameter has been at the same time enlarged. The objection to the wide interspaces between the plants may be obviated by sowing the seeds of some other grass flowering about the same time with it. Perhaps P. trivialis would be found to answer the purpose. It is one of the hardiest grasses known, and will grow in many places where no no other species will flourish. Sheep fatten as tonishingly when fed upon it, and all grazing animals eat it with avidity. It keeps green and succulent after the seeds are ripe, even until the heavy frosts of winter. .It loses less weight in drying than any other species. It is objected in some quarters that it is very difficult to exterm inate from the soil, and probably in some cases the objection is well founded; but there is no difficulty in raising goed corn from its sod with the free use of the cultivator.