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Section TEPHRODES 
One species in North America. 2. V. cinerea. 
Section LEPIDAPLOA 
Some or all of the heads sessile, in scorpioid cymes of 1-many heads. 
Cymes elongated, simple or branching, bearing usually numerous heads, 
each subtended by a bracteal leaf. I. Scorptoideae foliatae. 
Cymes reduced to 1-4 heads, viele therefore frequently appear sessile 
in the axils of the upper lea Il. Scorpioideae reductae 
Cymes much shortened, the heals ela aggregated in capitate or 
subcapitate clusters. . Scorpioideae aggregatae. 
ae elongated, simple or freely bra: a Hanae usually numerous 
heads, which are not subtended by es leav 
Vv. Serpe aphyllae. 
Heads mainly peduncled, in corymbiform or paniculate clusters, not scor- 
pioid or racemose. 
Branches of the inflorescence repeatedly dichotomously branched, the 
internodes successively and uniformly decreased in length, forming 
re: nicles. Vv. 
Branches of the panicle aggregated or separated by short intericdes: 
peduncles all about the same length, forming subumbellate rounded 
panicles . Laniculatae umbelliformes. 
Branches of the panicle irregular in ieavth, the uppermost heads sessile 
or short-peduncled, the lower on more elongated peduncles, forming 
crowded or lax, irregular or oe Lee 
. Paniculatae verae. 
I. SCORPIOIDEAE FOLIATAE 
* Involucre 8-10 mm. high, its scales subulate, straight, erect or somewhat 
spreading, not appressed, or on 
+ Leaves acute or acuminate, hirsute to glabrate. ARGYROPAPPAE. 
Leaves of an oblong type, broadest above the middle, attenuate at base. 
eaves 8-12 cm. long, softly and densely hirsute beneath. 
3. Vi argyropappa. 
Leaves 6 cm. long or less. 
Leaves scabrellate above, sparsely pilose or glabrate. 
‘Leaves pilose on both sides. 5. Vir penatfetl. 
Leaves of an ovate type, broadest below the middle, obtuse at base. 
V. hirsutivena, 
tt Leaves obtuse, bullate above, densely tomentose aa PINETICOLAE. 
. pineticola. 
** Involucre 4-5 or rarely 7 mm. high, its scales not subulate, —— or 
rely spreading, irregularly imbricated in a few serie 
+ Cymes elongated, bearing numerous heads. 
tInner scales acute or acuminate. 
