EQUISETUM.] EQUISETACE^E. 473 



genus 1; species 25. AFFINITIES. None direct. PROPERTIES. The 

 cuticle abounds in siliceous cells ; whence the stems of some are used 

 for polishing. 



Germination and impregnation as in Filices ; but the spores are usually 

 (functionally) 1-sexual. 



1. EQUISE'TUM, L. HORSE-TAIL, PADDOCK-PIPES. 

 Characters of the Order. ETYM. equus, 



* Fruiting stems simple or rarely branched, succulent ; barren appearing 

 later, I/ranched ; branches simple. 



1. E. arven'se, L. ; barren stems 6-19-grooved, branches spreading, 

 sheaths of fruiting stems distant loose with teeth ribbed to the tip. 

 Roadsides, banks and fields ; ascends to nearly 2,000 ft. in the N. of England ; 



frt. April. Barren stems erect or decumbent, slightly scabrid, usually 

 ending in a long naked point ; branches crowded, erecto-patent, 4-gonous ; 

 fertile stems (rarely with branches) stouter, shorter ; sheaths scarious. Dis- 

 TBIB. Europe (Arctic), N. Africa, N. Asia, Himalaya, N. America. 



2. E. pratense, Ehr. ; barren stems scabrid 8-20-grooved, branches 

 spreading, sheaths of fruiting stems close-set, ribs of teeth not reaching 

 the tip. E. umbrosum, Willd. ; E. Drummondii, Hook. 



Marshes, rare, from Perth and Aberdeen to York and Lancashire ; ascending 

 to 1,200 ft. in the N. of England; N. of Ireland, local; frt. April. 

 Closely allied to E. arvense, but greener, less glaucous, more scabrid, with 

 more numerous ribs and branches ; the barren stem terminates in an abrupt 

 brush of branches as in E. sylvaticum. Barren stems 1-2 ft., sometimes 

 bearing a cone, slender, abrupt ; branches simple, slender, usually spread- 

 ing, 3-4-gonous, sheaths very short ; fertile much stouter, sheaths very lax, 

 funnel-shaped. Cones f-1^ in. DISTRIB. Europe (Arctic) N. of the Alps, 

 Italy, Siberia, N. Americar 



3. E. maximum, Lamk. ; barren stems 20-40-grooved, branches sub- 

 erect, sheaths of short fruiting stems close large loose, teeth 2-ribbed. 

 E. Telmateia, Ehr. ; E. fluviatile, Sm. not L. 



Bogs, ditches, &c. from Skye and Aberdeen southwards ; ascending to 

 1,200 ft. in Yorkshire ; frt. April. Barren stems 3-6 ft., A in. diam. ; 

 branches 4-gonous, slender, erecto-patent, sheaths very short ; fertile 

 8-10 in., ^-^ in. diam. including the large lax sheaths. Cone 2-3 in., 

 obtuse. DISTRIB. Europe from Denmark southwards, N. Africa, W. Asia, 

 Siberia, N. America. 



** Fruiting and barren stems subsimilar, simple or branched. 



4. E. sylvat'icum, L. ; stems 10-18-grooved, branches recurved or 

 deflexed divided, stem-sheaths lax, teeth long obtuse, teeth of branch- 

 sheaths 3-ribbed to the tip. 



Copses and hedgebanks, from Devon and Kent northwards ; ascending to 

 2,700ft. in the Highlands; frt. April-May. Readily recognized by the 

 elegant appearance of the whorls of compound recurved branches. Stem 

 1-2 ft., nearly smooth. Teeth of branch-sheaths 3-5, large. Cones f-1 in., 

 short, ovoid-oblong, obtuse. DISTRIB. Europe, N. Asia, N. America. 



5. E. palus'tre, L. ; stems 5-12-grooved, branches simple, stem- 

 sheaths short appressed, teeth acute, tips membranous. 



