'08 SYSTEMATIC BOTANY. 



Sub-kingdom II. 



CRYPTOGAMIA, ACOTYLEDONES, OR ELOW- 

 ERLESS PLANTS. 



Class III. ACOTYLEDONES. 



Sub-class I. AcrogencB. 



Natural Order 286. Eilices.— Thr Eern Order {fig. 1088). 

 — Character. — Herbs with rhizomaTous stems{fig. 12), or ar- 

 borescent plants (fig. 13). Leaves, or fronds as they are com- 

 monly called, arising irregularly from the rhizome (fig. 12), or 

 placed in tnfts at the apex of the stem (fig. 13) ; almost always 

 circinate in vernation (figs. 12, 13, and 271); simple or com- 

 pound (figs. 12 and 785). Fructification consisting of sporangia 

 or capsules (figs. 783 and 784), collected in heaps (sori) usually on 

 the under surface or at the margin of the fronds, or rarely on 

 the upper surface, or occasionally arranged in a spiked manner 

 on a simple or branched rachis (fig. 785) ; the sori are either 

 naked (fig. 783) or covered by a membranous scale (indusium) 

 (fig. 78i). Sporangia stalked (fig. 786) or sessile, and either 

 annulate (fig. 786) or exannulate. Spores enclosed in the 

 sporangia (fig. 786). (For further particulars upon the fructifi- 

 cation of Eerns, see pp. 359 — 362.) 



Division of the Order, and Examples of the Genera. — This 

 order is commonl}'^ divided into three sub-orders, which are fre- 

 quently regarded by botanists as separate orders. 



These sub-orders are calJed Polypodiese, Dan?eefe, and Ophio- 

 glossese. Their distinctive characters are as follows : — 



Sub-order 1. PoJypodiecB or VolypodiacecB. — The Polypody Sub- 

 order, or Eerns propsr (figs. 783-786). Eronds circinate in 

 vernation. Sporangia or capsules, more or less annulate, 

 usually collected in sori on the under surface or at the 

 margin of the fronds, or occasionally arranged in a spiked 

 manner on a simple or branched rachis. Examples: — Poly- 

 podixmi, Asplenium, Hymenophyllum, Osmunda, 



Sub-order 2. T)a7i(Bece, Banmaace, or Marattiacecp. — The Dansea 

 Sub-order, — Eronde circinate in vernation, and all fertile. 

 Sporangia or capsules arising from, or imbedded in, the under 

 surface or back of the fronds, more or less united, exannulate. 

 £!rrtwp^('5.-— Danasa, Marattia. 



Sub-order 3. Ophioglossece or OphioglossacccB. — The Adder's 

 Tongue Sub-order (fig. 1088). Eronds not circinate vx ver- 



