KEY FOR THE PLANT KINGDOM 155 



thalloid in some cases. Male (antheridium) and female (archegonium) organs 

 are produced. Asexual spores in spore cases which open at the top, in true mosses. 



I. Bryophyta. 308 



Spores alike or unlike, microspores and macrospores developing into flat 

 or irregular prothallia ; these bear the reproductive organs, (antheridia and 

 archegonia) ; flowers and seeds absent; usually a well developed vascular system. 



II. Pteridophyta. 312 



Plants with a microsporangium (anther) containing the microspores (pollen 

 grains) which develop a tubular body, the prothallium (pollen tube) a macro- 

 sporangium (ovule) containing the macrospore (embryo-sac) which develops 

 into a minute prothallium ; this remains enclosed in the macrosporangium ; 

 after the fertilization of the egg cell in the macrospore a seed develops; plants 

 with flowers and usually well developed tissues, the epidermis, parenchyma and 

 vascular. (Bmbryophyta Siphonogama) . D. Spermatophyta. 325 



Ovules not enclosed in an ovary. I. Gymnospermae. 325 



Resinous trees or shrubs; wood with tracheids, tracheae usually absent; 



fruit a cone of dry or fleshy scales. Coniferae. 327 



Ovules enclosed in an ovary. II. Aiigiospcrmac. 332 



Embryo with 1 cotyledon ; stem without distinction into pith, wood, and 

 bark ; endogenous ; leaves usually parallel veined ; flowers generally on the plan 

 of 3. 1. Monocotyledonae. 332 



Flowers generally small, unisexual, regular with persistent perianth ; 6 or 3 

 stamens ; carpels free or rarely united ; fruit a berr}', drupe or nut ; embryo 

 small ; endosperm copious. Principes. 369 



Palm-like plants with palm-like leaves ; flowers naked or with thick leaves 

 of perianth; carpels 2 or 4 with 2 or 4 placentae. Synanthae. 



Mostly fleshy herbs or thalloid floating plants ; inflorescence a fleshy spadix 

 subtended by a spathe or naked or reduced to few or solitary flowers on the 

 margin or back of a thalloid body. Spathiflorae. 370 



Herbs generally with narrow leaves ; flowers usuallj^ complete, their parts 

 mostly on the plan of 3; corolla regular or nearly so; ovary compound superior; 

 endosperm mealy. Farinosae. 2>12 



Mostly herbs ; flowers with a well developed perianth, usually regular and 

 complete; usually on the plan of 3; ovary superior or inferior, compound; 

 endosperm fleshy or horny. Liliiflorae. 374 



Large herbs; flowers irregular; ovary inferior, compound; composed of 

 several united carpels ; seeds generally arillate, frequently with perisperm and 

 endosperm. Scitamineae. 390 



Herbs, tropical species frequently epiphytes ; flowers very irregular, or in 

 one family regular, generally complete and perfect ; parts of the perianth in 

 3's or 6's; ovary inferior, compound; seeds numerous; endosperm present or 

 absent. Microspennae. 392 



Embryo usually with two cotyledons; stem usually with wood, pith and 

 bark marked, usually exogenous ; leaves mostly netted veined ; flowers fre- 

 quently on the plan of 5. 2. Dicotyledoneae. 395 



Petals separate or distinct from each other or wanting ; occasionally some 



