XXXV111 INTRODUCTION. 



SUBCLASS II. GYMNOSPERMOUS EXOGENOUS PLANTS 



Ovules naked (not contained in an ovary), supported by an open 

 scale or leaf, or else terminating a branch, and fertilized by the direct 

 application of the pollen. 



Stem branching. Leaves simple. CONIFERS, 455 



Stem simple, palm-like. Leaves pinnate. CYCADACE^E, 400 



CLASS H MONOCOTYLEDONOUS OR ENDOGENOUS 



PLANTS. 



Stem composed of cellular tissue and scattered bundles of woody 

 fibre and vessels, destitute of proper pith, bark, or concentric layers, 

 and increasing in diameter by the deposition of new fibrous bundles. 

 Leaves mostly alternate, entire, and parallel-veined, commonly sheath- 

 ing at the base, seldom falling off by an articulation. Floral enve- 

 lopes usually by threes. Cotyledon single. 



* Floral envelopes none. Flowers on a spadix. 



Stemless, floating herbs. 



Plants frond-like, with no distinction of stem and leaves. LEMNACE/E, 4GG 

 Leaves clustered, spreading. Flowers axillary. Pistia in ARACEvE, 405 



Caulescent, leafy, rooting herbs. 



Fruit a berry. Spadix enclosed in a spathe. ARACE M, 4G4 



Fruit an achenium. Stem immersed, floating. NAIADACE^E, 4G8 



Stem not immersed, erect. TYPHACE^E, 467 



* * Floral envelopes ( perianth) single or double, not glumaceoiis. 



Ovary adherent to the perianth. 



Stamens and pistil united into a column. Flowers irregular. ORCHIDACE.35, 477 



Stamens and pistil separate. 

 Flowers monoecious or dioecious. 



Flowers enclosed in a spathe in the bud. Aquatics. HYDROCHARIDACE^E, 475 

 Flowers without a spathe. Leaves reticulate. Terrestrial vines. 



DIOSCOREACE^E, 501 

 Flowers perfect. 



Ovary 1-celled. Stamens 3. Leaves minute. BURMANNIACE.E, 476 



Ovary 3-celled. Stamen 1. Flowers irregular. CANNACE/E, 491 



Stamens 3. Anthers extrorse. IRIDACE^E, 499 



Stamens 3 or 6. Perianth woolly or scurfy. HjEMODORACE^E, 496 

 Stamens 6. Perianth smooth or hairy. AMARYLLIDACE^E, 492 

 Ovary free from the perianth. 

 Perianth single (calyx). 



Flowers on a spadix. Ovary solitary. ARACE^E, 404 



Ovaries 4. Stem leafy. NAIADACE,E, 408 



Flowers on a scape, spiked. Leaves rush-like. JUNCAGINE^E, 520 



Flowers on axillary peduncles. Leaves oval. ROXBURGHIACE^, 50G 



Perianth double, (calyx and corolla). 



Calyx and corolla alike, or nearly so, and glume-like. JUNCACEjE. 519 



Calyx and corolla alike, or nearly so, and not glume-like. 

 Leaves ribbed and netted-veined. Fruit a berry. SMILACEJE, 502 



