516 



DICOTYLEDONES. 



most frequently a bilobed stigma, or a bipartite style. The fruit 

 is nearly spherical, most frequently a capsule. The seeds are erect, 

 and have a large hilum at the base. The embryo is curved, with 

 leaf-like, thin, bilobed, most frequently folded cotyledons; endo- 

 sperm absent or mucilaginous. 



I. CONVOLVULEJ;, BINDWEED GROUP. The majority are twining 

 (to the left) herbs, with latex. The leaves are scattered, without 

 stipules, often long- stalked, and nearly always with cordate base ; 

 some are palmately lobed. The flowers are most frequently solitary 

 in the leaf-axils, large, quickly withering. Convolvulus (Fig. 552), 

 Calystegia (unilocular ovary, 2 large bracteoles), Ipomcea, Batatas, 

 Evoknlus (with a doubly bifid style), Colony ction, Pharbitis, etc. 



FIG. 552. Convolvulus tcammonia. 



2. DICHONDRE^E. This group is a more primitive form, not twining, and 

 without latex. It has 2 j'ree carpels with basal style (as in Boraginacese) and 

 valvate corolla. 



3. CUSCCTE^;, DODDER GROUP (Fig. 553). Parasites, with round, 

 filamentous stems, bearing only scale-like leaves and almost desti- 

 tute of chlorophyll (they are reddish or yellowish) ; they are 

 parasitic upon other plants, around which they twine, first with 

 narrow, compact coils from which haustoria (Fig. 553 A) are de- 

 veloped which enter the host-plant, and then with wider coils by 

 which they raise themselves to other portions of their host or try 

 to reach other plants. On germination a very temporary primary 

 root is developed, which bears root-hairs as far as the tip (root- 

 cap is wanting) ; it only serves as a kind of reservoir for water, and 

 perishes very soon after the seedling has fastened on to a host. 

 The embryo is filamentous and rolled up spirally (Fig. 553 C), and 



