132 



KEY TO THE FAMILIES AND GENERA 



D. Blade of spathe deciduous; spat he 

 constricted in middle, leaving a long 



tube when blade falls Schismato~ 



DD. Blade of spathe persistent, at least [glottis. 



until ripening of spadix. 



E. Seeds anatropous Homalomena. 



EE. Seeds orthotropous Philodendron. 



cc. Plant with st. upright, aerial: stamens 



united into a synandrium. 

 D. Pistillate fls. crowded, without 

 staminodia; staminate fls. with only 



2-3 separate stamens AglaoTiema. 



DD. Pistillate fls. with staminodia inter- 

 spersed ; st aminate fls. with 3-4 



united stamens Dieffenbachia* 



CCC. Plant with st. subterranean. 



D. Seeds orthotropous or nearly so: the 

 connate staminodia of the pistillate 

 fl. forming an involucre around the 



gyncecium Peltandra. 



DD. Seeds anatropous: staminodia. of pis- 

 tillate fls. separate Zantedeschia. 



BB. Lvs. netted-veined (i.e. veins of 2nd, 3rd, 



and 4th order netted). 

 C. Milk-tubes absent. 



D. Raphides absent (raphides are acicu- 

 lar crystals found in bundles in the 

 plant-cell). 



E. Lvs. differentiated into petiole and 

 blade: seeds anatropous. 



F. Seeds without endosperm Pathos. 



FF. Seeds with endosperm Artthurium. 



EE. Lvs. without distinction into petiole 



and blade: seeds orthotropous Acorus. 



DD. Raphides present in ground tissue of 



st. and Ivs. 



E. Fls. without perianth; spathe decidu- 

 ous before ripening of spadix: 

 plants mostly climbing. 

 F. Seeds with endosperm and axial 



embryo. 

 G. Foliage-lvs. many on each 



shoot Stenosper- 



GG. Foliage-lvs. I on each shoot in [motion. 



addition to several bracts Raphidophora. 



PF. Seeds without endosperm. 



G. Ovary 2-celled Monstera. 



GO. Ovary 1-celled Scindapsus. 



EE. Fls. with perianth; spathe not 



deciduous: sub-shrubs Spathiphyllum, 



CC. Milk-tubes present in fibro-vascular 



bundles. 



D. The milk-tubes branched; veins of 2nd 

 grade fusing into a collective vein 

 between veins of 1st grade. 

 E. Seeds with endosperm: st. not 

 climbing. 



F. Ovary with basal placenta Alocasia. 



FF. Ovary with parietal placentae Colocasia. 



FFF. Ovary with broad, nearly central 

 placentae. 



G. Style small Caladium. 



GO. Style disk-like, projecting 



beyond ovary Xanthosoma. 



EE. Seeds without endosperm: st. climb- 

 ing Syngonium. 



DD. The milk-tubes simple, straight; veins 



not as* above. 



E. Perianth present; fls. bisexual. 

 F. Lvs. not arrow-shaped. 



G. Ovary 2-celled; 2 ovules in each 

 cell, suspended from middle of 



partition Lysichitum. 



GG. Ovary 1-celled, 1-ovuled. 



H. Ovule from apex of cell: 

 spadix short, nearly globu- 

 lar Symplocarpus. 



HH. Ovule basal: spadix cylindri- 

 cal Orontium. 



FF. Lvs. arrow-shaped. 



G. Plants are shrubs with climb- 

 ing or creeping sts.: petioles 

 and sts. usually prickly or 



warty Cyrtosperma. 



GO. Plants tuberous Dracontium. 



EE. Perianth absent; fls. unisexual (bisex- 

 ual in Calla). 



F. Fls. bisexual:lvs. not arrow-shaped. Calla, 

 FF. Fls. unisexual: Ivs. various. 



a. Spadix with a sterile terminal 

 appendage, or with sterile 

 wings: sts. various. 



H. Seeds without endosperm. . . . Amorphophal- 

 HH. Seeds with endosperm. [lus, 



i. Appendage of spadix pro- 

 jecting much beyond the 

 spathe, or included and 

 free. 



j. Spadix with rudimentary 

 fls. between the fer- 

 tile staminate and fer- 

 tile pistillate fls. , or 

 staminate infl. border- 

 ing immediately on the 

 pistillate infl. 

 K. Placenta parietal: Ivs. 

 arrow-shaped or 



lanceolate Arum. 



KK. Pl.'iccntic apical and 

 basal : Ivs. pedately 

 divided. 



I* Fertile staminate 

 infl. bordering im- 

 mediately on the 



pistillate infl Dracunculus, 



LI* Fertile s't a m i n a t e 

 infl. separated 

 from pistillate infl. 

 by many rudi- 

 mentary ns Helicodiceros. 



KKK. Placenta basal. 



L. Lvs. pedately 

 divided : seeds 2 



or more Saitromatum* 



LL. Lvs. ovate, lanceo- 

 late or linear: 

 seeds mostly 1 .... Biarum, 

 jj. Spadix without rudimen- 

 tary fls., but a space 

 between the staminate 

 and pistillate fls., or 

 unisexual. 

 K. Ovary with many 



ovules. 



L. Staminate fls. of 1 

 stamen: Ivs. ovate 

 or arrow-shaped : 

 .spadix bisexual.. . . Arisarum* 

 LL. Staminate fls. of 2-5 

 stamens: Ivs. 3- 

 or many-parted : 

 spadix unisexual. . . Arissema. 

 KK. Ovary 1-ovuled: stam- 

 inate and pistillate 

 portions of spadix 

 separated by a par- 

 tition which reaches 

 out from wall of 



spathe Pinellia. 



II. Appendages of the spadix 

 wing-like on the 2 sides, 

 thus dividing the bila- 

 biate spathe into 2 

 chambers, the anterior of 

 which contains a stam- 

 inate fl., the posterior a 



pistillate fl '. Ambrosinia. 



GG. Spadix without such appendage 

 or wings: sts. subterranean, 

 creeping Nephthj/tit. 



Other genera described are Callopsis, Cryptocoryne, Epiprem- 

 ntim, Gamogyne, Gymnostachys, Staurostigma, Typhonium and 

 Typhonodorum. 



204. ALISMACE.&. 



A. Carpels inserted in a whorl on a small recep- 

 tacle 1. Alisma. 



AA. Carpels densely crowded in many series on a 



large oblong or globose receptacle 2. Sagittaria, 



205. BUTOMACEiE. 



A. Petals marcescent; stamens 9; carpels 6 1. fiutomus. 



AA. Petals deciduous; stamens numerous; car- 

 pels 15-20 2. Limnoch- 



[aris 



206. NAIADACE.fi. 



A. Fls. hermaphrodite, spicate; perianth 4- 



divided ; stamens 2 or 4 1*. Potamogettm. 



AA. Fls. unisexual, axillary; perianth 0; stamens 1. 2. Zannichellia 



207. APONOGETONACE^E. 

 The only genus Aponogeton. 



