390 ACROQENOUS PLANTS 



SERIES II. 



CKYPTOG'AMOUS OR FLOWERLESS 

 PLANTS. 



VEGETABLES destitute of proper flowers (stamens and pistils), and 

 producing seeds of homogeneous structure (called spores), in which 

 there is no embryo or plantlet manifest, before germination. 



CLASS III. 



ACKO'GENOUS OR APEX-GROWING 

 PLANTS. 



Cryptogamous Plants with a distinct axis (stem and branches], growing 

 from the apex only, containing woody fibre and vessels, and usually 

 with a distinct foUage. 



ORDER CXIX. EQUISET.VCEAE. 



Leafless plants, with rush-like hollow articulated stems,, rising from creeping 

 rhizomax, and terminated by the fructification, which is in the form of a cone, or 

 spike, composed of peltate pedicellate scales bearing the sporanges (or spore-cases) 

 underneath. 



510. EQUISE r TUIwr, L. 



[Latin, Eqmis, a horse, and Seta, a bristle ; resembling a horse-tail.] 

 Sporanges 6 or 7, adhering to the under side of the angular scales of 

 the cone, 1 -celled, opening down the inner side and discharging the 

 numerous loose spores. Spores embraced by 4 hygrometric clavate 

 filaments (called elaters), which relax or uncoil when dry. Stems 

 striate-grooved ; joints separable, embraced by sheaths which are 

 toothed at summit; branches, when present, verticillate. 



1. Stems annual, the fertile stems different from the sterile ones. 

 f Fertile stems never branching. 



1. E. arvense, L. Sterile stems with simple ascending 3- or 

 4-angled branches ; sheaths of the fertile stems remote. 



FIELD EQUISETUM. 



Fertile stems appearing first, 6 to 9 inches high, with an ovoid-oblong brownish 

 spike about 2 inches in length ; sheaths large, loose, with long acute teeth, dark 

 purplish-brown, whitish at base. Sterile stems 9 to 15 inches high, with a verticil 

 of slender articulated branches from the base of the sheaths ; branches 4 to 8 

 inches long, scabrous, green, each branch with its own sheath at base, and sheath- 

 ed at each articulation. 



Hob. Moist grounds ; borders of thickets : frequent. Fr. April, May. 

 ft Fertile stems producing branches after fructification. 



2. E. syl vat iciim, L. Sterile and fertile stems both branch- 

 ing; branches compound, curved downward. 



WOOD EQUISETUM. Horse-tail. 



Stems 9 to 18 inches high, the joints invested with loose sheaths which are divid- 

 ed at summit into several broad lanceolate tawny-ferruginous teeth, or sometimes 

 parted into 2 or 3 lance-oblong segments ; fertile stems with verticils of rather short, 

 divaricate, or deflected branches, from the base of the 3 or 4 uppermost sheaths, 

 and terminating in an oblong-ovoid brownish S2>ike about an inch in length ; stcr- 



