URTICACEAE. 



Vol. I. 



i. Parietaria pennsylvanica Muhl. Pennsyl- 

 vania Pellitory. Fig. 1563. 



P. pennsylvanica Muhl.; Willd. Sp. PI. 4: 955. 1806. 



Annual, pubescent, stem weak, simple or spar- 

 ingly branched, ascending or reclining, very slender, 

 4-15' long. Leaves lanceolate or oblong-lanceolate,' 

 membranous, dotted, acuminate at the apex, nar- 

 rowed at the base, 3-nerved and with 1-3 pairs of 

 weaker veins above, slender-petioled, 1'-^' long, i'-¥ 

 wide; petioles J'-l' long, almost filiform; flowers 

 glomerate in all except the lowest axils, the clusters 

 shorter than the petioles ; bracts of the involucre 

 linear, 2-3 times as long as the flowers; style almost 

 none ; achene about i" long. 



On dry rocks and banks, Maine to Ontario, British 

 Columbia, Nevada, Tennessee and Mexico. June-Aug. 

 Hammerwort. 



Family 12. LORANTHACEAE D. Don, 

 Prodr. Fl. Nepal. 142. 1825. 



Mistletoe Family. 

 Parasitic green shrubs or herbs, containing chlorophyll, growing on woody 

 plants and absorbing food from their sap through specialized roots called haus- 

 toria (a few tropical species terrestrial).- Leaves in the following genera oppo- 

 site, in Razoumofskya reduced to opposite scales. Flowers regular, terminal or 

 axillary, clustered or solitary, dioecious or monoecious, and perianth simple, or 

 in some exotic genera perfect, and with perianth of both calyx and corolla. 

 Calyx-tube adnate to the ovary, its limb entire, toothed or lobed. Stamens 2-6; 

 anthers 2-celled or confluently i-celled.' Ovary solitary, erect; style simple or 

 none; stigma terminal, undivided, obtuse. Fruit a berry. Seed solitary, its testa 

 indistinguishable from the endosperm, which is usually copious and fleshy. 



About 21 genera and 500 species, widely distributed ; most abundant in tropical regions. 

 Leaves scale-like, united at the base; anthers 1 -celled; berry peduncled. 1. Razoumofskya. 



Leaves thick, flat ; anthers 2-celled ; berry sessile. 2. Phoradendron. 



i. RAZOUMOFSKYA Hoffm. Hort. Mosq. 1808. 

 [Arceuthobium Bieb. Fl. Taur. 3 : 629. 1819.] 

 Small or minute fleshy glabrous plants, parasitic on the branches of coniferous trees, 

 their branches 4-angled, and leaves reduced to opposite connate scales. Flowers dioecious, 

 not bracted, solitary or several together in the axils of the scales. Staminate flowers with a 

 2-5-parted calyx and usually an equal number of stamens, the i-celled anthers sessile on the 

 segments. Pistillate flowers with the ovary adnate to the tube of the calyx, the calyx-limb 

 2-parted. Disk present in both kinds of flowers. Berry fleshy, ovoid, more or less flattened, 

 borne on a short somewhat recurved peduncle. Embryo enclosed in the copious endosperm. . 

 [In honor of Alexis Razoumofski, Russian botanist.] 



About 10 species. Besides the following, 7 or 8 others 

 occur in western North America and Mexico, 2 in Europe 

 and Asia. Type species : Razoumofskya caucasica Hoffm. 



i. Razoumofskya pusilla (Peck) Kuntze. 

 Small Mistletoe. Fig. 1564. 



Arceuthobium pusillum Peck, Rep. N. Y. State Mus. 25 : 69. 



1873- 

 Arceuthobium minutum Engelm. Bull. Torr. Club 2 : 43. 



Without description. 1871. 

 Razoumofskya pusilla Kuntze, Rev. Gen. PI. 587. 1891. 



Plant inconspicuous, stems 2"-io" long, nearly terete 

 when fresh, somewhat 4-angled when dry, simple or 

 sparingly branched, greenish-brown, slender. Scales 

 suborbicular, appressed, obtuse, about i" wide, connate 

 at the base; flowers strictly dioecious (the staminate 

 and pistillate plants sometimes on different trees), soli- 

 tary in most of the axils, longer than the scales; berry 

 ovoid-oblong, acute, about 1" long, nodding on a slightly 

 exserted peduncle ; seeds enclosed in a viscid mucus. 



On twigs of spruces and tamarack, Newfoundland to Con- 

 necticut, New York, Pennsylvania and Michigan. June. 



