396 CRYPTOGAMIA EQDISETACEJE. <3L. XXIV. 



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. Perennial : flowers in April 

 and May: grows in moist woods : frequent. Eng. Bat. vol. zxvii. pi. 

 1874. Eng. FL vol. iv. p. 336. 1511. 



5. E. limc'Sitm. 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 branchless, 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. paluttre. Marsh Hone-tail. Sterile and fertile stems deeply fur- 

 rowed, branched throughout ; branches about ten in each whorl, mi- 

 nutely roughish, erect. Stems about two feet high : spike cylindrical. 



Perennial : flowers in June and July : grows in waterv places : frequent. 

 Eng. Bot. vol. xxix. pi. 2021. Eng. Fl. vol. iv. p. 338. ' 1513. 



7. E. hyemd'U. Greater Rough Horse-tail. Sterile and fertile stems 

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

 rowed ; sheaths whitish, black at the top and bottom, their teeth pointed, 

 deciduous. Stems from one to two feet high: spike elliptical. Pe- 

 rennial : flowers in July and August : grows in boggy woods : not common. 

 The cuticle of all the Equiseta contains siliceous earth, on which account 

 they are used for polishing wood and metals. This species is more emi- 

 nently 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 Rough Horse-tail. Stems branchless, 

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

 nous, 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, in Angus-shire, and by Mr. W. Wilson in Lanca- 

 shire, and in Ireland. Eng. Bot. vol. xxviii. pi. 1987. Eng. Fl. vol. iv. 

 p. 341. 1515. 



Besides the Ferns, Lycopodinece, and Equisetaceae, 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 PH*NOOAMOUS PLANTS, or those belonging to the first twenty- 

 three classes of the Linnaean system, 1462 species, arranged in 459 

 genera, have been enumerated and characterized, in the preceding pages. 



Of the CRYPTOGAMOUS PLANTS, or those forming the twenty-fourth or 

 last class, there have been briefly described only 53 species, disposed in 

 17 genera. 



