PETALOIDE.E 



283 



(fig. 256), a common herb of marshes and rice-fields, 

 with elliptic-acute radical leaves, milky juice, herma- 

 phrodite flowers, and many ovules scattered over the 

 inner wall of the carpels (superficial, s.p.). The 

 perianths are petaloid and serve to attract insects. 



Nat. Order 5. 

 Naiadacece. — Sca- 

 pigerous marshy 

 herbs, either sub- 

 merged or float- 

 ing, with elon- 

 gated branched 

 stems. Flowers 

 hermaphrodite or 

 unisexual, green 

 and inconspicu- 

 ous, in spikes, 

 racemes, or spa- 

 dices. Perianth 

 o, or 4-parted, in- 

 ferior. Stamens 

 I to 6. Pistil of I 

 to 6 carpels, apo- 

 carpous. Fruit 

 achenes, follicles, 

 or drupes. The 



Order is temperate and tropical. Common plants: 

 Pond Weed or Potamogeton indicus has small green 

 2-sexual flowers in scapes rising from a spathe, perianth 

 of 4 segments; carpels 4, i-ovuled; floating leaves 

 large, coriaceous; submerged leaves longer, narrower, 

 and membranous. P. crispus (^g. 257) is a pond- 

 weed with oblong crisped leaves. This family agrees 

 with the SpadiciflorcB in some respects, and is there- 

 fore sometimes included in that sub-class. 



FIgf. 256. — Buiomopsis lanceolata 

 s.fi., Superficial placentation. 



