Oh. XXL] / CLASSES AXD ORDERS. 1^5 



531 ORDER 2, DIGYNIA, two pistils. We here find the impor- 

 ant family of grasses, of which there are many different gene- 

 ra. They are distributed throughout the globe, and furnish 

 many of the most useful vegetables for man and beast. 



532. Among the most useful of the grass family, are wheat, 

 rye, barley, oats, Indian corn, and rice, besides meadow-grass 

 and those kinds which are eaten by cattle. 



533. Indian corn, though it is ranked with the grasses on ac 

 count of its long and linear leaves, its tibrous roots, and some 

 other particulars, yet it is not placed in the third class, becauso 

 its stamens and pistils are not in the same flower. Rice is 

 placed in the sixth class on account of the number of its sta- 

 mens. You see that natural families are sometimes separated 

 by the artificial classification ; as in th-e second class two grass- 

 es were mentioned, which were placed there on account of hav- 

 ing two stamens. 



534. Grasses have fibrous roots, their stems are of that kind 

 called culms, being long, slender, and hollow, and having knots 

 from which arises a long linear or lanceolate leaf surrounding 

 tLe stem like a sheath. 



535. The stems of grasses grow internally, or from the centre 

 outwards ; this is. the reverse of what appears in the oak, the 

 Dew wood of which encircles the old. 



536. The flowers of the grasses are found in what is called 

 (he ear or head ; and consist of a calyx of two green husks 

 called a glume; within this calyx is the blossom, consisting ot 

 a husk of two pieces ; these husks are the chaff, which is sepa- 

 rated from the seed by threshing. If y.ou observe a blossom ol 

 wheat, or of common meadow grass, you will see three sia 

 mens with large anthers, and two pistils with feathered stig 

 mas. 



537. The grasses have no seed vessel, but the seed is con 

 tained within the husks, which gradually open and throw out 

 their contents ; this scattering of the seed is the cause of the 

 very general distribution of grasses. 



5 38. Wheat, rye, and oats, are annual plants ; that is, their 

 roots die every year, and the plant is renewed by means of the 



531. What important family do we find in the 2d order of tbe :lass 

 T riandria ? 

 53*2. Which are some of the most useful of the grass family 1 



533. Why are not Indian-corn and Rice classed with tne gra,scs ? 



534. What is said of the roots of grasses 1 



535. What of their stems ? 

 530. What of their flowers ? 



537. Have the grasses a seed vessel! 



538. What grasses are annual, and what are perennial 2 



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