PLATANACE*. 201 



6* PIIj'EA, Lindl. Richweed. Clearweed. 

 P. pu'mila, Gray. Stem 3-18 inches high. Leaves ovate, 

 coarsely-toothed, 3-ribbed. — Cool moist places. 

 7. BCEHME'RIA, Jacq. False Nettle. 



B. eylin'driea, Willd. Stem 1-3 feet high, smoothish. 

 Leaves ovate-oblong or ovate-lanceolate, serrate, 3-nerved, 

 long-petioled. Stipules separate. — Moist shady places. 



8. PARIEVA'RIA, Toum. Pellitory. 

 P. Pennsylvan'iea, Muhl. A low annual, simple or 

 sparingly branched, minutely downy. Leaves oblong-lance- 

 olate, thin, veiny, roughish with opaque dots. — Usually in 

 crevices of limestone rocks ; not very common. 



9. CAM'KABIS, Tourn. Hemp. 



C. Sati'va, L. (Hemp.,) Common everywhere along road- 

 sides and in waste places. 



10. nil'ItllJXVS, L. Hop. 

 H. Lu'pulus, L. (Common Hop.) A twining perenniaL 

 Leaves heart-shaped, mostly 3-5-lobed, petioled. Calyx of 

 fertile flower a single sepal. In fruit the calyx, achene, 

 etc., sprinkled with yellow resinous grains, which give the 

 hop its taste and smell. 



Order LXXXV. PLAT ANA' CE.S;. (Plane-tree F.) 



Represented only by the Genus 



PliArANIIS, L. Plane-tkbe. Bottonwood. 



P. oecidenta'lis, L. (American Plane-tree or Stcamore.) 

 A fine large tree found in south-western Ontario. Leaves 

 alternate, rather scurfy when young, palmately-lobed or 

 angled, the lobes sharp-pointed : stipules sheathing. Flow- 

 ers monoecious, both sterile and fertile ones in catkin-like 

 heads, without calyx or corolla, but with small Scales inter- 

 mixed. Ovaries in the fertile flowers club-shaped, tipped 

 with the thread-like simple style, and downy at the base. 

 Fertile heads solitary, on slender peduncles. The white 

 bark separates into thin plates. 



