ARISTOLOCHIACEAE (BIRTHWORT FAMILY) 351 



axils. Leaves oval, thin, deciduous, short-petioled. (Name said by its author 

 to be derived from a Greek word for Daphne.) DARBYA Gray. 



1. N. umb611ula Raf. Low shrub, 3-8.5 dm. high; leaves 3-6 cm. long, 

 mostly acute ; flowers small, greenish; drupes at length globose, 1-1.3 cm. in 

 diameter. (Darby a umbellulata Gray.) Parasitic on roots of trees, Va. to S. C. 

 and Ala. Apr., May. 



LORANTHACEAE (MISTLETOE FAMILY) 



Chiefly shrubby plants with coriaceous greenish, yellowish, or olive-brown 

 foliage, parasitic on trees. 



1. Phoradendron. Anthers 2-celled. Berry globose, pulpy. Leaves foliaceous. 



2. Arceuthobium. Anthers 1-celled. Berry compressed. Leaves scale-like, connate. 



1. PHORADENDRON Nutt. FALSE. MISTLETOE 



Flowers small, dioecious, in short catkin-like jointed spikes, usually several 

 to each short fleshy bract or scale, and sunk in the joint. Calyx globular. 

 3 (rarely 2-4)-lobed ; in the staminate flowers a sessile anther is borne on the 

 base of each lobe ; in the fertile flowers the calyx-tube adheres to the ovary ; 

 stigma sessile, obtuse. Berry 1 -seeded, pulpy. Yellowish-green woody para- 

 sites on the branches of trees, with jointed much-branched stems and thick 

 firm persistent leaves. (Name composed of <t>&p, a thief, and 8tv8pov, tree ; from 

 the parasitic habit.) 



1. P. flavSscens (Pursh) Nutt. (AMERICAN MISTLETOE.) Leaves obovate, 

 glabrous. On various deciduous trees, chiefly at low altitudes, N. J. and e. Pa. 

 to Fla. and N. Mex., inland in Miss, basin to Mo., s. Ind., and centr. O. 



2. ARCEUTH6BIUM Bieb. 



Calyx mostly compressed ; the staminate usually 3-parted, the pistillate 

 2-toothed. Anthers a single orbicular cell, opening by a circular slit. Berry 

 compressed, on a short recurved pedicel. Parasitic on Conifers, glabrous, with 

 rectangular branches and connate scale-like leaves. (From d/>/tev0os, the juniper, 

 and pios, life.} 



1. A. pusillum Peck. (DWARF MISTLETOE.) Very dwarf, the slender scat- 

 tered or clustered stems 6-20 mm. high, usually simple, olive-green to chestnut ; 

 scales obtuse ; flowers solitary in most of the axils ; fruit narrowly ellipsoid, 

 2 mm. long. (Eazoumofskya Ktze.) On Picea and Larix, Nfd. and e. Que. 

 to Pa. and n. Mich. ( Wheeler}. Apr., May. Often causing " witch's brooms " 

 on the host-plant. 



ARISTOLOCfflACEAE (BIRTHWORT FAMILY) 



Twining shrubs, or low herbs, with perfect flowers, the conspicuous lurid 

 calyx valvate in bud and coherent (at least at base) with the 6-celled ovary, 

 which forms a many-seeded 6-celled capsule or berry in fruit. Stamens 5-12, 

 more or less united with the style ; anthers adnate, extrorse. Leaves petioled, 

 mostly heart-shaped and entire. Seeds anatropous, with a large fleshy rhaphe, 

 and a minute embryo in fleshy albumen. A small family of bitter-tonic or 

 stimulant, sometimes aromatic, plants. 



1. Asarum. Stemless herbs. Stamens 12, with more or less distinct filaments. 



2. Aristolochia. Caulescent herbs or twining shrubs. Stamens 6, the sessile anthers adnate to 



the stigma. 



