20 



FAMILIES OF FLOWERING PLANTS. 



flattened achene somewhat like that of a buttercup. The i)hintainlike 

 leaves from which the po])ular name of the family is derived are most 

 conspicuous in JZ/.s/z/rc, which is a familiar bog plant throughout the 

 continent. In this genus the flowers are small and inconspicuous, but 

 in S<((i!ft<irni they are often of some beauty, the inner })erianth series, 

 or corolla, consisting of three large white petals of the texture of 

 crepe. S<i(j!tt'i/'!<i is called arrowhead from the sha])e of its leaves, 

 which exhibit great diversity of form, but in many species are more 

 or less like an arrow or s})ear head in outline. (See Fig. 15.) 



Family IJutomaceae. — Water Foppy Family. Four genera, each 

 monotypic, or consisting of a single species, and all exotics. The 



characters of the family, how- 

 ever, are well illustrated in the 

 l)eautiful yellow water poppy 

 { Ili/d roch i/.s /ii/]nj>Ii(i!(lrs\ so 

 often cultivated in ponds and 

 tubs. The plants are herbs 

 with extensively creei)ing root- 

 stocks, or l)ranching stems, and 

 scapose flowers, solitary in the 

 water pop})y and und)elled in 

 the other genera; the flowers 

 are perfect, with a perianth 

 composed of calyx and corolla, 

 the latter often conspicuous. 

 The fruit resembles that of the 

 arrowhead or water plantain, 

 but the ovary contains more 

 numerous ovules. 



FAM. 16^-Tape grass or wild celery, (VuUi.n.ria j. .^ ^^^ • j Valllsneriaceae 



spinilix) showing enlarged stammate and pistillate '' 



flowers, also the fruit. (After Britton and Brown. ( H y d O C ll a 1" i d aCCae). Tai^e- 



lU. FI. North. U. S ) ,. . , •. i^ 



grass or _broo;s-l)it I'amHv. 



Fourteen genera and 40 species 

 of wide distribution, chiefly tropical. The onl}" genera occurring in 

 American are Vaifis/wr/a, Plillotr'ni and llalopli'ihi. The family is 

 distinguished mainly by the dioecious flowers, produced from the axils 

 of enveloping bracts known as spathes; there is a small perianth com- 

 posed of three to six segments. It is an interesting fact that Yallix- 

 nerl<(, the true eel-grass or ''wild celery'', whose long riI)l)on-like 



