60 ELEMENTS OF BOTANY. 



anthers transversely 2-celled ; pistillate flowers with the ovary 

 inferior, stigma sessile ; berry 1-seeded. 



P. FLAVESCENS (Pursh.) Nutt. Mistletoe. Very round, bushy, 

 branches very brittle at the joints, opposite or whorled, 6 in.-2 ft. 

 long; leaves flat, coriaceous or somewhat fleshy, nearly veinless, 

 obovate, entire, with short petioles ; flowering sjDikes solitary or 2-3 

 together in the axils of the leaves ; berry globose, white, glutinous. 

 April-May. Parasitic on many deciduous trees. 



30. ARISTOLOCHIACEJE. BTRTHWORT FAMILY. 



Herbaceous plants, acaulescent or with twining and leafy 

 stems ; leaves alternate, exstipulate, petioled, mostly ronnd- 

 ish or reniform ; flowers axillary, solitary or clustered, per- 

 fect, regular or irregular ; calyx tubular, 3 or 6-lobed, usually 

 colored ; petals none ; stamens 6-12, inserted on the ovary ; 

 pistils 1, ovary mostly 6-celled, many-seeded. 



I. ASARUM. 



Perennial, acaulescent, aromatic herbs with slender, branch- 

 ing rootstocks ; leaves long-petioled, from reniform to hastate ; 

 flowers axillary, peduncled ; calyx regular, 3-lobed, withering- 

 persistent ; stamens 12, the filaments partially united with 

 the style and usually prolonged beyond the anthers; ovary 

 6-celled with parietal placentae, many-seeded ; mature capsule 

 globose, often somewhat fleshy. 



1. A. YiRGiNicuM L. Virginia As arum. Leaves evergreen, 

 1-3 to each plant, glabrous, mottled, round-cordate, entire, 2-3 in. 

 long and broad ; petioles glabrous or pubescent along one side, 3-7 

 in. long ; flowers nearly sessile, greenish without, dull purple within, 

 |-| in. long, tube inflated below, narrowed at the throat, lobes spread- 

 ing. April- May. Rich, shady woods in the upper districts. 



2. A. ARiFOLiuM Michx. GiNGER-ROOT. Leaves cordate or 

 halberd-shaped, 2-4 in. long, usually mottled ; petioles pubescent, 

 3-8 in. long ; flowers pitcher-shaped, about 1 in. long, peduncled, 

 dark purple within, lobes short and rounded. March- April. Shady 

 woods in the lower districts. 



