396 CRYPTOGAMIA EQTJISETACEJE. [CL. XXIT. 



with compound, four-sided, smooth branches, curved downwards. 



Stems about a foot high, erect, with short branches, each 



whorl with a pale -brown torn sheath above it: spike oblong. 

 Pterennial: flowers in April and May: grows in moist woods: 

 frequent. Eng. Bot. vol. xxvii. pi. 1874. Eng. Fl. vol. iv. p. 336. 



1511. 



5. E. limosum. Smooth Naked Horse-tail. Sterile and fertile stems 

 naked, or branched at the upper part ; the branches about fifteen 



in each whorl, simple, smooth, ascending. Stems from two to 



three feet high, smooth to the touch, furrowed, sometimes branch- 

 less, more frequently branched : spike small, oblong. Perennial : 

 flowers in June and July : grows in marshes and at the edges of 

 lakes and rivers : frequent. Eng. Bot. vol. xiii. pi. 922. Eng. Fl. 

 vol. iv. p. 339. 1512. 



6. E. palustre. Marsh Horse-tail. Sterile and fertile stems deeply 

 furrowed, branched throughout ; branches about ten in each 



whorl, minutely roughish, erect. Stems about two feet high ; 



spike cylindrical. Perennial : flowers in June and July : grows 

 in watery places : frequent. Eng. Bot. vol. xxix. pi. 2021. Eng.FL 

 vol. iv. p. 338. 1513. 



7. E. hyemdle. Greater Rough Horse-tail. Sterile and fertile stems 

 generally branchless, sometimes branched at the base, very rough, 

 furrowed; sheaths whitish, black at the top and bottom, their 



teeth pointed, deciduous. Stems from one to two feet high : 



spike elliptical. Perennial : flowers in July and August : grows 

 in boggy woods : not common. The cuticle of all the Equiseta 

 contains siliceous earth, on which accourit they are used for polish- 

 ing wood and metals. This species is more eminently qualified 

 for that purpose, and is largely imported from Holland. Eng. Bot. 

 vol. xiii. pi. 915. Eng. Fl. vol. iv. p. 339. 1514. 



8. E.variegdtum. Variegated Bough Horse-tail. Stems branchless, 

 very rough, branched at the base ; sheaths black, with white mem- 

 branous, lance-shaped teeth. Stems about eight inches high, 



ascending, furrowed. Perennial : flowers in July and August : 

 found by Mr. G. Don on the sands of Barry, Angus-shire, and by 

 Mr. W. Wilson in Lancashire, and in Ireland. Eng. Bot. vol. 

 xxviii. pi. 1987. Eng. Fl. vol. iv. p. 341. 1515. 



Besides the Ferns, Lycopodinese, and Equisetaceee, of which the 

 species are briefly described above, there are in this class the 

 Mosses, Lichens, Algae, Fungi, and other groups or orders, the 

 description of which must be sought in other works. 



Of the PHJENOGAMOUS PLANTS, or those belonging to the first 

 twenty-three classes of the Linnsean system, 1462 species, arranged 

 in 459 genera, have been enumerated and characterized, in the 

 preceding pages. 



Of the CRTPTOGAMOUS PLANTS, or those forming the twenty- 

 fourth or last class, there have been briefly describejd only 53 

 species, disposed in 17 genera. 



