AEACEAE. 65 



plete, borne on a spadix accompanied by a spathe, or in Lemnaceae 1 or 

 few in a pouch in the plant-body. Perianth inconspicuous or wanting. 

 Fruit baccate or utricular. 



Plants normal, with the flowers on a spadix, this sometimes subtended by or partly 

 enclosed in a spathe. Fam. 1. Araceae. 



Plants reduced to small floating thalloid structures, with one 

 or few flowers. Fam. 2. Lemnaceae. 



Family 1. ARACEAE. Arum Family. 



Fleshy mostly acaulescent plants. Leaves with simple or divided 

 blades. Flowers perfect, monoecious, or dioecious. Perianth of 4-6 scale- 

 like members, or wanting. Androecium of 4—10 stamens. Gynoecium of 

 1 carj^el, or of several united carpels. Fruit a berry or a utricle. 



Flowers monoecious or dioecious : perianth wanting. 



Leaf -blades palmately divided : spathe involute below, hooded above : spadix 



included, terete or obscurely angled. 1. Arisaema. 



Leaf-blades pedately divided : spathe convolute throughout : 



spadix exserted, more or less flattened or 2-edged. 2. Muricauda. 



Flowers perfect : perianth of several scale-like members. 



Spadix surrounded by a spathe. 3. Spathyema. 



Spadix naked, merely subtended by a spathe. 



Spadix terminating the club-shaped scape. 4. Orontium. 



Spadix borne somewhat laterally on the leaf-like scape. 5. Acorus. 



1. ARISAEMA Mart. Herbs of swamps or woods, with corms. Leaf- 

 blades palmate, 3-5-divided. Scape permanently erect. Spadix clavate or 

 cylindric, the fertile portion partially flower-bearing. Spathe cornucopia-like. 

 Fruits red. — Spr. and sum. — Jack-in-the-pulpit. Indian-turnip. 



Hood of the spathe brown with light stripes : naked portion of the spadix clavate : 

 fruits 8-12 mm. in diameter. 1. A. triplujlhtm. 



Hood of the spathe black or red-brown : naked portion of the 



spadix cylindric : fruits 4-5 mm. in diameter. 2. A. pusillum. 



1. A. triphyllum (L.) Torr. Plants mostly over 4 dm. tall: leaf -segments 

 8-30 cm. long; blades dull, rather abruptly short-acuminate: spathe-blade short- 

 acuminate, often striped with purple or brown and green within : fruits 8-12 

 mm. thick. — Common, in swamps and on moist hillsides. 



2. A. pusillum (Peck) Nash. Plants mostly less than 3 dm. tall: leaf -segments 

 5-12 cm. long: spathe-blade short-acuminate, red-brown or almost black within: 

 fruits 4—5 mm. thick. — E. S. Rather rare, in swamps. — Quartzite, schists. 



2. MURICAUDA Small. Herbs with corms: leaf -blades pedate, 5-17- 

 divided. Scapes permanently erect. Spadix whip-like, the fertile portion 

 covered with flowers. Stamens 4. Spathe wholly convolute. Fruits red. 



1. M. Dracontium (L.) Small. Leaf -segments cuneate to oblanceolate, 1-3 dm. 

 long: spathe 3-10 cm. long: fruits 6-8 mm. thick. — Common in low alluvial 

 grounds. — Spr. — Green-dragon. Dragon-root. 



3. SPATHYEMA Eaf. Coarse swamp herbs with cordate leaf -blades, the 

 petioles, and the scapes partially underground. Spadix oblong or globular, 

 enclosed in the thick cochleate, colored spathe, the scape rigid. Flowers perfect. 

 Perianth of 4 hooded members. Fruits immersed in the spadix. 



1. S. foetida (L.) Eaf. Plant garlic-scented, glabrous: leaf -blades 2-5 dm. 

 long, often 3 dm. broad : scapes erect, mainly subterranean : spathe preceding 

 the leaves, 8-15 cm. long, beaked, mottled: fruit-head persistent, 9-15 cm. in 



Lancaster County Flora 5. 



