552 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Stamens curved, often converging; 
calyx various; anther-bearing 
stamens 2 or 4; inflorescence 
various. 
Shrub; calyx regularly 5- 
toothed; anther-bearing 
stamens 2......-...--..-- 10. PotromInTHA (p. 556). 
Herbs, calyx 2-lipped; anther- 
bearing stamens 2 or 4. 
Flowers in terminal heads; 
leaves large; anther- 
bearing stamens 4...11. CLrvopoprum (p. 556). 
Flowers in axillary clusters 
or in interrupted 
spikelike inflores- 
cences; leaves small; 
anther-bearing  sta- 
mens 2..........-.-- 12. Hepeoma (p. 557). 
Upper lip of the corolla more or less con- , 
cave. 
Anther-bearing stamens 2. 
Calyx equally 5-toothed; con- 
nective short, the anther 
sacs confluent; flowers in 
crowded, bracteate, ver- 
ticillate or terminal 
heads, the bracts often 
colored... ..........---- 13. Monarpa (p. 559). 
Calyx 2-lipped, the upper lip 
obscurely 3-toothed or en- 
tire, the lower 2-toothed; 
connective long, with a 
perfect anther sac at one 
end and a rudimentary 
one at the other; flowers 
never in headlike clus- 
ters...............-.--.-14, Sarvia (p. 560). 
Anther-bearing stamens 4. 
Upper stamens longer than the 
lower. 
Calyx distinctly 2-lipped; 
flowers very small, ob- 
scured by the numerous 
‘e bracts.............----.-15. Monpavica (p. 562 
Calyx about equally 5- 
toothed; flowers usually 
larger and the bracts of 
the inflorescence not con- 
spicuous. 
Anther sacs parallel or 
nearly so; stamens di- 
vergent..............-- 16. AGASTACHE (p. 562). 
Anther sacs divaricate; sta- 
mens approximate in 
pairs............0---. 17. NEepETA (p. 564). 
