bei 
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1104 The Achenial Hairs of Townsendia. (November, 
grandiflora) may be well shifted into closer proximity with the 
glochidiate sub-section. 
The next step was to examine the species represented as having 
simple hairs. I was prepared for such, because in other genera I 
have sometimes found the simple (as also the multicellular) hairs 
of the perianth invading the achenial surface so as to become in: 
termingled with the duplex hairs. But in Townsendia no such 
phenomenon has as yet presented itself to my view. Although 
quasi-simple hairs abound on the achenes of some of the species, 
they are all really duplex. For descriptive purposes the term 
“simple” may perhaps be retained ; but they are only apparently 
such. The semi-hairs sometimes grow finer upwards, ending in 
a straight point; the companion semi-hair will then be shorter, 
with its point hiding in the wall of the longer one, or with th 
point slightly or even abruptly diverging; and in. these canes 
third division may be sometimes seen nearer the base, thus giving 
variously the aspect of hair simple, or two-, or even three-toothed; 
in such cases the semi-tubes of the composite hairs are unequal; 4 
third tooth sometimes arises from an extra process on a sem 
hair. In T. florifer, where the point of one semi-hair was fre 
quently hid behind the other, by rolling it under the cover glass 
we could readily bring it into view. Occasional triplicity of these 
hairs accords with what occurs in other genera, and is caused by 4 
one of the basal cells growing up beside the semi-hair which * 
bears ; we have observed it in some species of Townsendia We 
so described in the Synopsis (7: Parryi, T. wilcoxiana, sekat 
it may perhaps be expected as an occasional variation, a 3 
all the non-glochidiate species. z 
The “glochidiate-capitellate ” character is merely incidental ® 
the gerteral binary structure of the hair. When the gie 
are of equal dimensións throughout, and when they a x p 
same level before they abruptly diverge, then the diverging Ho 
tremities spread out and recurve like the two flukes of an care a 
and in one species (T. wi/coxiana) the whole duplex hair pe 
long and slender, and its long extremities are circinately hey a 
The average dimensions of the hairs in the other species g a 
to .35™™ long, by .022™" in breadth. Each of them 15 5 sae í : 
tube, like the two barrels of a fowling-piece. Ina wee he. 
T. Rothrockii I was able to chase air-bubbles up and ach otber. 
tubules, those in adjoining tubes being indepen dent of ea o 
ASW 
