THE FAMILIES OF FLOWERING PLANTS. 

 By Charles Louis Pollard. 



II. THE CAT-TAILS, PONDWEEDS AND ARROWHEADS. 



THERE are few of us, I fancy, who are not familiar with the 

 wand-hke, brown spike and sword-shaped leaves of the Cat- 

 tail. Its presence always indicates a marsh or swamp where- 

 in the explorer is likely to find himself beyond his depth if he 

 ventures to penetrate far in his efforts to gather a supply of "tails." 

 The Cat-tail family ( Typhacece) contains but a single genus, and is 

 therefore easily recognized. The spike consists of innumerable tiny 

 flowers, reduced to mere stamens and pistils, with no perianth or flo- 

 ral envelope, but with numerous intermixed bristles. The upper por- 

 tion of the spike, at flowering time, is lighter in color and less dense ; 

 this is composed entirely of stamens, which soon fall away, leaving 

 the pistils below to form a cotton-like mass in fruit. The genus is 

 widely distributed in temperate regions. 



The Bur-reed family {SparganiaceiE), also including one genus, 

 Sparganhim^ was formerly included with the Cat-tails. The plants 

 possess, however, an entirely different aspect, and grow in wet, grassy 

 places or even in deep water, but not in dense colonies like Typha. 

 Here the staminate and pistillate flowers are likewise separate, but 

 are borne in several globular heads on the upper branches of the stem, 

 and not in a single terminal spike. The fruit is hard and nut-like, 

 much larger than that of the Cat-tail, and without any intermixed 

 bristles; while the leaves are long and grass-like. 



The Pondweeds ( Naiadacece ) constitute a large and difficult fam- 

 ily. The genera are few in number, and the great majority of species 

 are comprised in Potamogeton^ which is. very appropriately translated 

 as " River- weed." Slow streams and rather shallow ponds are the 

 favorite habitat of these plants, whose smooth, oval leaves floating on 

 the surface of the water, may be noticed in many such situations. 

 Nearly all our American Potamogetons occur in New England and 

 the Middle States. It is not necessary to enumerate the remaining 

 nine genera of the family, as they agree in having the flowers with a 

 distinct perianth, or envelope of four parts; in this respect they are 

 somewhat anomalous among the Monocotyledons, which will be re- 

 membered as having the parts of the flower mostly in threes. All the 

 Naiads are immersed aquatics, with branching stems, and the flowers 

 in small spikes. The submerged leaves often differ curiously in shape 

 from those that float on the surface. The pistils become in fruit usu- 



