FLORA OF THE DISTRICT OF COLUMBIA. 113 



90. Carex lurida Wahl. 



Wet places, everywhere. Summer. Eastern U. S. (C. tentaculata Muhl.; includ- 

 ing C. lurida exundans Bailey.) 

 Exceedingly variable; spikes subglobose to cylindric, sessile to long-pedunculate. 



91. Carex bullata Schkuhr. 



Swamps; Hyattsville. May- June. Me. to Ga. 



92. Carex rostrata Stokes. 



Bennings Bridge, June 8, 1879 ( Ward). Nearly throughout the U .S. (C. utriculata 

 Boott; C. vesicaria of Brereton's Prodromus, probably.) 



93. Carex intumescens Rudge. 



Low or wet woods of the Coastal Plain. May-Sept. Eastern U. S. 



94. Carex louisianica Bailey. 



Swamps along the Potomac and Eastern Branch. July-Aug. Southeastern U. S., 

 north to D. C. 



95. Carex lupulina Muhl. 



Swamps. July-Aug. Eastern U. S. 



C. lupulina pedunculata Dewey, with more or less pedunculate spikes, occurs 

 sparingly. 



Carex buxbaumii Wahl. (C. fusca of Steele's list) has been reported, but there are 

 no specimens in the National Herbarium. 



18. ARACEAE. Arum Family. 



Leaves compound, composed of 3 or more leaflets. Flowers in a dense spike, this 

 surrounded by a spathe 1. ABISAEMA. 



Leaves simple. 

 Leaves linear, less than 1.5 cm. wide; flower spike naked, borne on a long, sharply 



3-angled stalk, the stalk prolonged above the spike 2. ACOKUS. 



Leaves broader than linear, usually more than 5 cm. wide; flower stalk not pro- 

 longed above the spike. 



Leaves tapering at the base; flower spike naked 3. OBONTITJM . 



Leaves not tapering at the base, usually somewhat heart-shaped or arrow- 

 shaped; flower spikes surrounded by a spathe. 

 Leaves ovate or oval, usually more or less heart-shaped; flower stalks very 



short and stout; sepals 4 4. SPATHYEMA. 



Leaves usually arrow-shaped and with long acute lobes at the base; flower 

 stalks usually long and slender; sepals none 5. PELTANDBA. 



1. ABISAEMA Mart. 



Leaves composed of 5-17 leaflets; spathe surrounding the flower spike erect, not 

 hooded 1. A. dracontium. 



Leaves composed of 3 leaflets; spathe hooded (curved down over the flower spike). 



2. A. triphyHum. 



1. Arisaema dracontium (L.) Schott. Green dragon. 

 Low rich woods; occasional. May-June; fr. Aug.-Sept. Eastern U. S. 



2. Arisaema triphyllum (L.) Torr. Jack-in-the-pulpit. 

 Moist woods and thickets; common. Apr-June. Eastern N. Amer. 



The species is a very variable one. The spathes are usually more or less colored or 

 striped with brownish purple, but sometimes the> are wholly green. Very often 

 plants are wholly staminate or wholly pistillate. A. triphyllum pusillum Peck is a 

 small form with the spadix 3-5 cm. long; in the larger plants the spadix is usually 

 5-7 cm. long. This form has been recognized as a species, A. pusillum (Peck) Nash, 

 but hardly seems worthy of special designation. 

 69289—19 8 



