ANGIOSPERM^E 



361 



In a very small number of Angiosperms, probably all reduced 

 types, there is no properly developed stem, the sporophyte approach- 

 ing the condition of a thallus. Such are the minute aquatic Lem- 

 naceae, the Rafflesiaceae and Balanophoraceae, which are endophytic 



FIG. 324. Runners of Strawberry. (After BAILEY.) 



parasites, resembling Fungi in their habits, and the Podostemonaceae, 

 aquatic Dicotyledons, some of which might be mistaken for Algae. 



Branching. Usually the stem is well developed and shows great 

 variety. The shoot may be unbranched (Erythronium Americanum, 

 Trillium), or it more commonly branches freely, either to form 



FIG. 325. Tubers of Potato. (After BAILEY.) 







flowers or for secondary vegetative shoots. True dichotomous 

 branching is rare (Zannichellia), and,' with few exceptions, lateral 

 members arise in the axils of leaves. If the stem develops little 

 woody tissue, it is said to be herbaceous ; if wood is well developed, 

 it is " woody " or " ligneous." 



