Ch. XIII] THE DICOTYLEDONS 541 



Equisetum-like in aspect, with very simple flowers in heads 

 or spikes. They are interesting because of their primitive 

 characteristics. The ovules contain many embryo-sacs (meg- 

 aspores) instead of the usual single one. The fertilization 

 is chalazogamic, i.e. the pollen tube enters haustorially by 

 the chalaza instead of through the micropyle, — a peculiarity 

 found in others of the simpler families. 



Order 2. Piperales: the Peppers and kin. Over 

 1000 species, mostly tropical, of small shrubs with simple 

 naked flowers in loose spikes. A tendency to scattering of the 

 fibro-vascular bundles suggests relation to Monocotyledons. 

 Some fruits yield a sharp-tasting oil, the basis of the pepper 

 of commerce. Here belongs the Saururus, or Lizard's Tail, 

 of our own wet fields. 



Order 3. Salic ales: the Willows and Poplars. About 

 160 species of soft-wooded trees and shrubs of temperate 

 and arctic regions, preferring wet places, especially riversides. 

 They become creeping in the Arctic regions. They are 

 dioecious, and bear close woolly catkins of naked flowers 

 which possess nectaries and are pollinated by insects despite 

 lack of a perianth ; and they produce hair-covered short- 

 lived seeds widely carried by winds. They have limited uses 

 in basket-making, etc. 



Order 4- Myricales: the Sweet Gales and kin. 

 About 35 species of shrubs, growing in barren places, with 

 clusters of simple, unisexual, wind-pollinated flowers ; most 

 familiar in the Bayberry of the coast (page 111), and the 

 "Sweet Fern" of barren uplands. 



Order 5. Juglandales: the Walnuts and Hickories. 

 About 35 species of large and valuable timber and nut trees 

 of temperate regions. They have long drooping catkins 

 of male blossoms, and small groups of pistillate flowers, 

 typically wind pollinated. The fruits are large nuts contain- 

 ing the familiar crinkled embryos. 



