XXX 
ANALYTICAL KEY. 
Perianth of 3 persistent green sepals and 3 ephemeral 
deliquescent petals Commelinacea. 
Stamens 6, dissimilar, or only three with perfect 
anthers Commelinacea. 
Perianth tubular, 6-lobed, . . . Pontederiacea. 
Perianth wholly glumaceous, of 6 similar divisions. 
Juncacea, 92 
Perianth partly glumaceous or chaff-like; flowers in very 
dense heads ; rush-like or aquatic. 
Flowers perfect; inner perianth of 3 yellow petals. 
Perfect stamens and plumose sterile filaments, each 3; 
pod 1-celled, many-seeded on 3 parietal placentae. 
Xyridacea. 
C. Glumaceous Division. — Flowers destitute of the proper 
perianth , except sometimes small scales or bristles, but cov- 
ered by scale-like bracts or glumes. 
Glume, a single scale-like bract, with a flower in its axil. 
Cyperacea. 
Glumes in pairs, of two sorts Graminea, 94 
Class III. CRYPTOGAMOUS ACROGENS. FLOWERLESS 
PLANTS. 
Destitute of stamens or pistils, iu fructification producing spores instead 
of seeds. Axis distinct (stem and branches) growing from the apex only, 
and furnished for the most part with distinct leaves ; reproduction by 
means of antheridia and archegonia, sometimes also by gemmation. 
Subclass I. PTERIDOPHYTES. Stems (and foliage when present) 
containing both woody fibre and vessels; antheridia or archegonia, or 
both, borne on a minute prothallus, which is developed from the spore on 
germination. 
Spores of only one kind ; spore-cases 
Borne beneath shield-shaped scales in a terminal spike; stems 
naked ; sheathed at the nodes. . . . Equisetacea. 
On the back or margin of fronds, circinate in vernation. Filices, 95 
Bivalvular; in special spikes or panicles; fronds erect iu 
vernation, from short, erect rootstocks. . Ophioglossacea. 97 
Solitary in the axils of leaves, 2-3- valved; low, long- 
