26 FAMILIES OF FLOWERING PLANTS. 
Many grasses with rapidly growing and branching rootstocks as 
the beach grass (Ammophila arenaria) share with numerous sedges the 
important function of sand-bind- 
ers; that is, they serve to hold 
the drifting sands along the coast 
and prevent the soil from being 
carried away by wind and waves. 
A number of species like the 
various pamras grasses of South 
America, the ribbon-grass (/’ha- 
laris) the ‘‘Job’s tears,’’ (Cod 
lachryma) and others are highly 
ornamental in cultivation, retain- 
ing their beauty when dried and 
cut. The use of several Andro- 
pogons in the manufacture of 
perfume has been mentioned; but 
it should be remembered that our 
3 own sweet vernal grass (Anthow- 
S anthum odoratum) when cut, 
properly dried and placed be- 
tween thin papers will exhale a 
delicate fragrance far superior to 
that of any sachet powder. 
While enumerating the uses 
_ sof this family we must reluctantly 
7S admit that it contains also some of 
Fi. 23.—Creeping Panic-grass (Panicum repens. the worst weeds known to farm- 
(After Scribner, Bull. No. 7, Div. of Agrost., U. S. Cred 
Dept. of Agric.) ers. The couch grass (Zriticum 
repens) the crab grass (Syntheris- 
ma sanguinalis) and several others are extremely difficult to eradicate 
when they have once taken possession of the ground. Among the 
largest genera of the Graminee may be mentioned Andropogon, with 
about 200 species; Paspalum, with 300; Panicum, with nearly 800; 
Agrostis, 100; Calamagrostis, 150; Danthonia, 100; Eragrostis, 100; 
Poa, 200; Festuca, 250; and Bambusa, 50. The figures illustrate 
various distinct types, showing in each case enlarged views of the in- 
florescence as well as the habit of the plant; the general similarity 
of structure however, will be noticed throughout. 
