ANALYTICAL KEY. 29 



Stamens 6, dissimilar, or only three witli perfect anthers. 

 Sepals 3, herbaceous; ephemeral petals 3, unequal. 



COMMKLINACE.^, 538 



Perianth tubular, 6-lobed Pontederiace^, 535 



Stamens 3, similar. Moss-like aquatic. . . . Mayace^e, 537 

 Perianth wholly glumaceous, of 6 similar divisions. . Juxcace^, 539 

 Perianth partly glumaceous or chaff -like ; flowers in very 

 dense heads. Kush-like or aquatic. 

 Flowers perfect ; inner perianth of three yellow petals ; 

 perfect stamens and plumose sterile filaments each 

 3 ; pod 1-celled, many-seeded on 3 parietal placenta;. Xyridace^, 53G 

 Flowers monoucious or dioicious, whitish-bearded ; sta- 



raens 4 or 3 ; pod 2 - 3-celled, 2 - 3-seeded. . Eriocaule^, 56G 

 C Glumaceous Division. Flowers destitute of proper perianth, except 



sometimes small scales or bristles, but covered bi/ scale-like bracts or glumes. 

 Glume a single scale-like bract with a flower in its axil. . Cyperace^, 567 

 Glumes in pairs, of two sorts. Gramine^, 623 



Class III. CKYPTOGAMOUS ACROGENS. (See p. 17.) 



Subclass I. PTERIDOPHYTES : with woody fibres and vessels. 

 Spores of only one kind ; spore-cases 



Borne beneath shield-shaped scales in a terminal spike; stems 



naked, sheathed at the nodes Equisetaceje, 675 



On the back or margin of fronds circinate in vernation. Filices, 678 



Bival-VTilar, iu special spikes or panicles ; fronds erect in vernation, 



from short erect rootstocks. . . . Ophioglossace^, 693 



Solitary in the axils of leaves, 2 - 3-valved ; low long-stemmed moss- 

 like evergreens; leaves small, in 4-16 ranks. Ly'COpodiacea:, 695 

 Spores of two kinds, large and small ; spore-cases 



Solitary in the axils of small 4-ranked leaves, or in the bases of 



linear radical leaves. .... Selagikellace^e, 697 



Enclosed in peduncled sporocarps ; leaves 4-foliolate. Marsiliace^, 700 



Sporocarps sessile beneath the stem; small, floating, pinnatcly 



branched, Avith minute imbricate leaves. . Salviniace-«:, 701 



Subclass II. BRYOPIIYTES : with cellular tissue only. [Cap- 

 sules not operculate, containing spores and usually elaters, in the fol- 

 lowing Orders.] 

 Capsule 4-valvcd, pedicellate ; plants leafy-stemmed, rarely thallose. 



JUNGERMANNIACE.E, 702 



Capsule 2-valved or valveless ; plants thallose. 



Thallus without epidermis; capsule with a columella, short-pedi- 



celled or sessile on the thallus. . . Axthocerotaceje, 726 

 Capsules borne beneath a pedunculate receptacle. Marchantiace^, 727 

 Capsules immersed in the thallus or sessile upon it, iudehisceut. 



Ricciace^, 730 



