LYCOPODIALES. 15 



Stems all alike ; spores mature in summer ; branches simple or none. 

 Sheaths, rather loose; branches usually long; stems bushy below, 



attenuate, upwards. 3. E. Uttorale. 



Sheaths appressed; branches usually short. 4. E. fluviatile. 



Stems perennial, evergreen; spikes tipped with a rigid pqint; stomata in 

 regular ro.ws. 

 Stems rough and taberculate, prominently ridged. 5. E. hyemale. 

 Stems not tubereulate; sheaths enlarged upwards. 6. E. laevigatum. 



1. Bqtjisetum arvense L. Common Sorsetail. 'M'.'p. 22. Sandy soil. 



Early spring. , . , 



2. Equisetum sylvaticum L. M. p. 22. Wet, shady places. Spring. 



Philadelphia— Tioga Station, Mart. '(B. f ''C), Gorgas Station (Je.). 

 Bucks — Nockajmixon (Cr.), Quakertpwn (Le,), Mqrrisyille (Ws.). Dela- 

 ware— Haverford (B. Sm.), -Concord (W. Tr.)> Chester— Greentree 

 (Pr.). Lancaster— (P.). Lehigh— Salsbiirg (Kr.), Lehigh Mountain, 

 Br. 3. B. Brinton (U. C, S.). Northampton— ("P.). 



New Castle — On limestone debris, Hoekessin. 



3. Equisetum littorale , Kuehl. M. p. 22. Sandy Biyer shores. 



Bucks — Point Pleasant (Er.). Delaware — - (P.). Northampton— 

 Easton (P.). Lancaster and Dauphin— On .-the Susquehanna (P.). 



4. Equisetum fluviAtile L. M. p. 23. In shallow water. Summer. 



Bucks— Nockamixon (He.), Perin Valley 1 (Ja.).' Delaware— Chester 

 (B. Sm,). Lehigh— Slatingdon (Kr.). Northampton— (P.). 

 Camden — Kaighn's Point (Ja.). 

 New Castle— Port Penn (Pr.), Hojly Qak, Canny. 



5. Equisetum hyemale L. Scouring Bush. M. p. 23. Wet places. Spring. 



Bucks— JNTqpkamixpn (He.) (Ke.), New Hope (Ws.). Delaware— Wawa 

 (Sa.), Eidley Creek, near Me.dia (B. Sm,), Concord (W. Tr.), Walling- 

 ford (Wn.). Chester— {P.). Lancaster— Paradise (St.). Lehigh— Cop- 

 lay (Kr.). Northampton— Bethlehem (Pr.). 



Burlington— Birmingham, Vincentown (C), Medford (Sts.). Gloucei' 

 ter— Westville (He.) (Wn.)'. Salem— Woodstown (He;) (Li.). Cum- 

 berland— Millville (Je.). M onmouth— Keyp6rt (C). 



New Castle — Noxentown, Canoy; Kiemensi, Paulkland, Centerville, 

 Commons; Harvey, Tatnall. 



6. Equisetum laevigatum A. Br. M. p. 23. Along streams and rivers in 



clay soil. 

 Northampton— Easton (P.). 



Order 4, LYCOPODIALES. 



Spores all of one sort and size. Earn. 1. Lycopodiaceae. 



Spores of two sizes. 



Leaves scale-like, 4-many-ranked, on branching stems. 



Earn. 2. Selaginellaceae. 

 Leaves elongated, clustered on a corm-like trunk ; aquatic or mud plants; 1 



Earn. 3. Isoetaceae. 



Family 1. LYCOPODIACEAE Michx. Club-moss Family. 



1. LYCOPODITJM L. Club-moss. 

 Sporanges borne in the axils of leaves, which are similar to those of the stem. 



