24 ANALYTICAL KEY. 



Perianth free from the ovary or very nearly so PA&B 



Epiphytes or air plants, with dry and often scurfy leaves, 



(Tillandsia) PINEAPPLE F. 414 



Stout aquatic herbs: flbwers irregular as to the (corolla- 

 like) perianth or stamens, or both, 



PICKEREL WEED F. 452 



Moss-like aquatic herb, with regular flowers . MAYACA F. 466 

 Terrestrial herbs or sometimes woody plants, not rush-like 



or grass-like 

 Perianth of green sepals and colored petals which are 



distinctly different 



Styles or sessile stigmas 3, separate: petals 3, not 

 ephemeral: leaves netted-veined, 



(Trillium) LILY F. 431 

 Style and stigma one: petals 3 or 2, ephemeral, 



SPIDERWORT F. 453 

 Perianth with all 6 (in one instance only 4) parts colored 



alike or nearly so 

 Anthers 1-celled : plants mostly climbing by tendrils 



on the petiole . . . SMILAX SUBF. 431 



Anthers 2-celled LILY F. 431 



Terrestrial or aquatic rush-like or grass-like plants, with 



small regular flowers 

 Not in a simple scaly-bracted head: perianth gluma- 



ceous, RUSH F. 456 



In a simple spike or raceme : flowers bractless, perfect : 



perianth herbaceous . WATER PLANTAIN F. 454 

 In a simple scaly-bracted head on a scape: leaves all 



from the root 



Perianth yellow, the inner divisions or petals with 

 claws: flowers perfect: pod 1-celled, many 

 seeded, the placentae parietal, 



YELLOW-EYED GRASS F. 456 

 Perianth whitish: flowers monoecious or dioecious: 



pod 2-3-celled, 2-3-seeded . PIPEWORT F. 456 

 GO Spadiceous Division, with flowers on a spadix or fleshy spike, peri- 

 anth none or not corolla-like, and no glumes. 

 Trees or woody plants with simple trunk, caudex, or stock 



Leaves persistent, long-petioled, fan-shaped and plaited or pinnate : 



spadix branched : floral envelopes of 3 or 6 parts . PALM F. 463 

 Leaves undivided, long-linear and stiff . . . SCREW PINE F. 462 

 Immersed aquatics, branching and leafy . . . PONDWEED F. 457 

 Small or minute free-floating aquatics, with no distinction of stem and 



foliage DUCKWEED F. 457 



Reed-like or Flag-like marsh herbs, with linear and sessile nerved leaves 

 Flowers naked in the spike: no distinct perianth CAT-TAIL F. 461 

 Flowers with a 6-parted perianth . . . (Acorus) ARUM F. 457 

 Terrestrial or marsh plants, with leaves of distinct blade and petiole, the 



veins netted ARUM F. 457 



OOO Glumaceous Division, with flowers enveloped by glumes (chaffy 



bracts'), and no manifest perianth. 



Ovary 3-celled or 1-celled with 3 parietal placentae, becoming a pod, 

 3-many-seeded : flowers with a regular perianth of six glumaceous 

 divisions. In structure of the flower most like the Lily Family ; 

 but the glumaceous perianth and the herbage imitate this division, 



RUSH F. 456 



Ovary 1-celled, l-ovuled, in fruit an akene or grain. True gluma- 

 ceous plants ; the glumes being bracts 



Glumes single, bearing a flower in the axil . . SEDGE F. 465 

 Glumes in pairs, an outer pair for the spikelet, an inner pair for 



each flower GRASS F. 467 



II. GYMNOSPERMS, without proper pistil, the ovules naked on a scale or 

 on the end of a short axis : cotyledons often more than two in a 

 whorl. 

 With palm-like columnar trunks or corn-like stock, and pinnate 



palm-like foliage CYCAD F. 485 



With branching trunks, and simple, mostly needle-shaped, linear, or 



scale-like entire leaves PINE F. 476 



