Equisetaceae. 1 79 



\\.—LYCOPODIUM. 



Thecae of one kind reniform, flattened, coriaceous. 

 Capsules in terminal cones, 684 

 Capsules axillary, L. Selago. 



684 Spikes in pairs stalked, .... L. clavatum. 



684 Spikes solitary sessile, ..... L. alpinum. 



LYCOPO'DIUM SELA'GO (83). Fir Club-moss. 6—8. Stem 2-6 

 (1822) in. erect forked, leaves in 8 rows linear-lanceolate acute, capsules 

 axillary. Heaths. 



LYCOPO'DIUM CLAVA'TUM (88). Common Club-moss, Stag's- 

 (1825) horn moss. 7 — 8. Stem i — 3 ft. long creeping, leaves imbricated all 

 round terminated by hairs, spikes stalked. Heaths. Fig. p. 136. 



LYCOPO'DIUM ALPI'NUM {55). Alpine Club-moss. 6—8. Stem 

 (1826)6—18 in. long creeping, leaves in 4 rows lanceolate, spikes sessile. 

 Mountains. 



III.— PILULARIA, 



PILULA'RIA GLOBULIF'ERA (56). Pill-wort. 6—8. Rootstock 

 (1832) creeping under water, leaves bright green 2 — 3 in. subulate, capsules 



globular axillary sessile 4-celled containing each a few macrospores and 



many microspores. Lakes and ponds. 



ORDER 91. — Equisetaceae. 



Flowerless plants with a distinct hollow and jointed stem, the joints sur- 

 rounded by membranous toothed sheaths, fructification in terminal cone-like 

 spikes or catkins consisting of polygonal scales bearing capsules on the ander 

 surface which contain numerous globose spores each provided with 4 elastic 

 clavate threads. 



Fruiting stems simple succulent appearing before 



the branched barren stem, 685 



Fertile and barren stems similar, 686 



685 Branches erect, E. maximum. 



685 Branches spreading, E. arvense. 



686 Branches compound E. sylvaticum. 



686 Branches simple, 687 



687 Stems smooth faintly striate, . , . E. limosum. 



687 Stem grooved rough, 688 

 688 Stem with 4 — 10 grooves, 689 

 688 Stem with 15 — 23 striae, E. hyemale. 



689 Sheaths with obtuse bristle-pointed teeth, . E. variegatum. 



689 Sheath with acute membranous-tipped teeth, . E. palustre. 



