96. 
5. Leaves strigose; peduncles and axis with 
Stalked gilandShvefstesi sic cile/c) else (ee elle) ele eles) scissile eel vo PENSylvanieum 
5. Leaves glabrous to scabrous; peduncles and axis 
glandless. (Also, ocreae short-strigose; base 
Of plan CKEePANG) erste cie's eres ele ci a's w olersitain stele ev) NYA Lop peroldes 
4. Ocreae with marginal cilia (lower ocreae may 
have top torn off). 
6. Plant annual, with fibrous roots. 
7. Mature calyx glandular-punctate. 
8. Calyx greenish; achene dull. 
Expected (P. hydropiper). 
8. Calyx white; achene lustrous........... P. punctatum 
7. Mature calyx glandless. 
9, Leaves ciliate on margins and lower 
veins; spikes terminal, 3-5 mm. thick; 
cilia of ocreae equal to or longer 
than the sheath... wsccnesccseccsssecss Fs CeSpitosum, 
var. longisetum 
9. Leaves glabrous, or sparsely strigose 
beneath; spikes in panicles, 7-11 mm. 
thick; cilia of ocreae shorter than 
the sheath. (Also, leaves often with 
purple blotch above but this 
character not, Consustent)cciiee siecle P. persicaria 
6. Plant perennial, with subligneous forking 
rootstocks. 
10. Mature calyx glandular-punctate.......... P. punctatum 
10. Mature calyx glandless. 
11. Calyx pink; leaves glabrous to 
scabrous; ocreae short-strigose...... P. hydropiperoides 
ll. Calyx white; leaves strigose; ocreae 
Stricose-hirsute... sss. seeceecescceee Fe Setaceum 
See also Appendix I., p. 229: P. cristatum. 
