SYNOPSIS OF NITELLA. 



A Monarthrodactyloe, ultimate segments of the leaves one-celled, 

 a. Simply branched. 



a. Homceophylloe. Leaves similar. 

 * Dioecious. 



f Extremely simple, leaves with only a single ray, very 



rarely branched, i. monodactyla A. Br. (S). 

 f f Branched. 



X Nucleus with 10-11 striae. 2. polygyra A. Br. 

 X X Nucleus with 5-7 striae. 



Fertile verticils contracted into a minute head, with 

 an elongated minute recurved peduncle, envel- 

 oped in mucus, with very short i -celled segments. 

 3. cernua A. Br. (S). 

 Fertile verticils not so contracted. 



-(- Glceocarpa (fruit enveloped in mucus). 



1) Fertile leaves of the female plant simple ; of 



the male plant, branched. Leiopyrena (nu- 

 cleus smooth). 4. syncarpa (Thuill. ) Kiitz. 



2) Fertile leaves of both sexes branched. Oxygyra 



(nucleus with sharp angles). 5. capitata 

 (N. ab E.) Ag. 

 H h Gymnocarpa (fruit naked, not enveloped in mucus), 



fertile leaves branched (Fig. 42). 6. opaca Ag. 

 * * Monoecious. 



f Fertile verticils not enveloped in mucus. 

 X Apices of leaves acute, rarely obtuse (Fig. 43). 7. 



flexilis Ag. 

 X X Apices of leaves gradually long acuminate. 8. acu- 



minata A. Br. 



Sterile leaves not much longer than the fertile ver- 

 ticils. 



-[- Small, habit like N. flexilis or N. mucronata. 

 i) Leaves loose. 



a) Sporophydia aggregated. 8a (Fig. 44). sub- 



glomerata A. Br. 



b) Sporophydia solitary, larger. 8b. Indica 



A. Br. 



