114 American Midland Naturalist Monograph No. 2 



48. Loranthaceae D. Don — Mistletoe Family 

 1. Phoradendron Nutt. 



P. flavescens (Pursh) Nutt. American Mistletoe. Parasitic on American 

 elm, black gum, oak, and other deciduous trees, s. III., northw. to Union and 

 Lawrence counties. 



49. Aristolochiaceae Blume — Birthwort Family 



I . Stem prostrate, rooting at the nodes; flowers regular, 3-lobed; calyx persistent; 



stamens 12 1. Asanim 



1 . Stem erect or twinmg; flowers very irregular, the calyx deciduous; stamens 6 



- 2. Arisiolochia 



1. AsARUM L. — Wild Ginger 



1. Calyx-lobes deltoid-ovate, shortly acuminate, scarcely longer than the calyx- 

 tube, spreading or reflexed at flowering time; woods, common. May 



A. reflexum Bickn. 



1 . Calyx-lobes lanceolate, caudate-acuminate, much longer than the tube, erect 

 or spreading at flowering time; wooded hillsides, local; extending southw. 



to Knox, Peoria, and Kankakee counties. May-June 



A. acuminatum (Ashe) Bickn. 



2. Aristolochia L. — Birthwort 



l.Low herb; flowers purple, 1-1.5 cm. long, solitary on sl'ender basal scaly 

 peduncles; calyx-tube curved like the letter S; leaves ovate-lanceolate, 

 cordate or hastate at base, thin, green on both sides; capsule subglobose, 

 ridged, about 1 cm. in diameter; rich woods, s. 111., rare. Virginia Snake- 

 root A. serpciitarta L. 



1. Twining shrub; flowers on axillary solitary pubescent bractless peduncles; 

 calyx tomentose, the tube abruptly bent, yellowish green, about 3 cm. 

 long, dark purple within; leaves suborbicular or broadly ovate, tomentose; 

 capsule ellipsoid, 4-6 cm. long; rich woods, s. 111., rare; extending northw. 

 to Wabash and Jackson counties. Dutchman's Pipe A. tomentosa Sims 



50. Polygonaceae Lindl. — Buckwheat Family 



I. Plants not climbing by tendrils; calyx-tube not enlarged in fruit; leaves with sheathing 

 stipules. 

 2. Sepals 6, the three inner ones becoming enlarged (valves) in fruit (except in the 



first species); stigmas tufted 1. Runwx 



2. Sepals 5, sometimes 4, nearly equal; stigmas capitate. 



3. Leaves not hastate-deltoid, or if so, the stems climbing by prickles or reclining. 

 4. Branches not at all adnate to the stem; flowers clustered (or if solitary not 



pink and the leaves not linear) 2. Polpgoitiim 



4. Branches more or less adnate to the internodes of the stem; stipular sheaths 

 oblique or truncate, glabrous; flowers solitary in the axils of the bracts in 

 slender panicled racemes; calyx pink; stamens 8; slender annual wiith 



linear leaves 3. PoI\}f;<>inlla 



3. Leaves hastate-deltoid; stem erect, smooth; flowers while; mature achenes much 



exserted from the calyx 4. Fagopwum 



I. Plants climbing by tendrils; calyx-tube conspicuously enlarged in fruit, tnclosing the 



achene ; stipules obsolete; flowers in slender axillary and terminal racemes 



5. Brimim hia 



