CRYPTOGAMIA.— EQJJISETACEiE. 3& 



long; branches densely leaved, terete, 8 — 12 in. 

 high. 



9. L. rupestre: stem creeping, with ascending subdi- 



vided branches ; leaves scattered, imbricate, li- 

 near-lanceolate, ciliate, ending in hairs ; spikes 

 solitary, sessile, quadrangular. 

 HAB. Rocks. July. Stem 2 — 3 in. long ; branch . 

 numerous, somewhat incurved ; plant grayish-green. 



* * * Spikes sessile ; leaves distichous. 



10. L. apodum: leaves 2-rowed, roundish-ovate, acute, 

 denticulate, Oat, acuminate ; spikes terminal, ses- 

 sile, nearly solitary, quadrangular. 



HAB. Wet rocky places. July. Resembling a 

 a moss, or Jungermannia ; creeping. 



* * * * Fructification axillary. 



11. L. lacidulum : leaves in 8 rows, linear-lanceolate, 

 denticulate, acute, spreading-reflexed ; stem as- 

 cending, bifid. 



HAB. Woods. July. Stem 3 — 12 in. long, nearly 

 erect, simp, or bifid, dark green. 



12. L. Selago : stem dichotomously branched, erect, 

 fastigiate ; leaves scattered in 6 equal rows, linear- 

 lanceolate, acuminate, entire, imbricate, rigid ; 

 fruit axillary. 



HAB. High mountains. About 6 in. high; leav 

 densely imbricated. 



EQUISETACEjE. 



612. EqUISETUM. Horse-tail. 



1. E. hyemale : stem simple, erect, very rough, na 



ked ; sheaths whitish, black at the base and sum 



mit. 



HAB. Woods and marshes. April. Stem 2 — 3f(. 



high, slend.,pale green ; spik. term., mostly solitary. 



1. E. arvense : sterile stems decumbent, with simple 

 branches, which are rough am) quadrangular ; fer 

 tile stem erect, simple ; sheaths simple, cylindri 

 eal| incisely-dentate. 



