398 Urticaceae Urtica 



Leaves alternate. 



Plants with stinging hairs; leaves large, with many pairs of sharp teeth; achenes 



about twice as long as the calyx, oblique, the style lateral 



1980. Laportea, p. 398. 



Plants without stinging hairs; leaves small, entire and undulate; achenes not as long 

 as the calyx, ovate, the style terminal 2007. Parietaria, p. 401. 



1974. URTlCA [Tourn.] L. Nettle 



Blades of leaves at the lower inflorescences generally more than half as wide as long, 

 ovate to broadly ovate, rather deeply cordate at the base, the lower surface gen- 

 erally covered with numerous, setose hairs, coarsely toothed 1. U. dioica. 



Blades of leaves at the lower inflorescences generally much less than half as wide as 

 long, ovate-lanceolate, oblong-lanceolate or lanceolate, rounded, truncate or sub- 

 cordate at the base, the lower surface lacking the setose hairs or with only a few 

 on the principal nerves and midrib, the margins with smaller and more regular 

 teeth than the preceding species 2. U. procera. 



1. Urtica dioica L. There is a specimen of this species in the 

 herbarium of the University of Notre Dame. It was collected by Nieuw- 

 land on the border of St. Joseph Lake, in St. Joseph County. He said it 

 is established there. 



Nat. of Eu. ; sparingly naturalized in the e. U. S. 



2. Urtica procera Muhl. in Willd. (Rhodora 28: 195. 1926.) (Urtica 

 gracilis of authors.) Tall Nettle. Map 812. Infrequent to frequent in the 

 lake area, becoming infrequent to very rare south of this area and re- 

 stricted mostly to low places in the alluvial bottoms of our principal 

 streams. It grows in rich, porous soil only in low ground and is found 

 about lakes and ponds in low woods, in low places along unimproved roads 

 in the lake area, in springy places throughout, and in wet places along 

 streams. 



This species is often confused with Urtica dioica L. which is a native 

 of Europe and has been reported as sparingly escaped in the eastern part 

 of the United States. It has been reported from Indiana but I am refer- 

 ring all of our reports except the one from St. Joseph County to this 

 species. The two species are difficult to separate. The leaves are variable 

 in texture, in shape of the blade and its base, in the number of setose hairs 

 on either surface, in the number of setose hairs on the stem, petioles, 

 and in the inflorescence, and in the size of the panicles. I have 28 speci- 

 mens from Indiana and 20 of these are monoecious and 8 are pistillate. 

 My specimens represent only the part of the plant with leaves when col- 

 lected and it is probable that the lower leaves and staminate inflorescences 

 of the pistillate specimens had fallen before the plants were collected. The 

 density of the stand of the plants has a marked influence upon them. 



N. S., Que. to N. Dak., southw. to N. C. and La. 



1980. LAPORTEA Gaud. 



1. Laportea canadensis (L.) Gaud. (Urticastrum divaricatum (L.) 

 Ktze.) Canada Nettle. Map 813. This is strictly a woodland nettle and 

 is found more or less frequently in low, wet woods throughout the 



