1883.] Achenial Hairs and Fibers of Composite. 33 
The Asteroidez and several other sub-orders have duplex hairs 
without elaters, the two divisions being acute at their tips, more or 
less divergent, generally unequal in length, one of them being 
sometimes very short (Fig. 5). These are a further modification ot 
the Inuloid pattern, and some Asteroidex (as the English daisy 
(Fig. 4) and Baccharis tvefotia) are of the Inuloid type, whilst 
Pluchea fetida, placed by Bentham and Hooker among the Inu- 
loids, agrees in this respect with the Asteroids, where DeCandolle 
placed it in the Prodromus. 
In many instances achenes represented by authors as smooth, 
have some of these duplex hairs indicating their real affinities; and 
in other instances (as Chrysopsis villosa and Sericocarpus,) the 
duplex hairs are very long and fine, as if they were simple hairs ; 
but still their Asteroid character is easily seen (Fig. 6 B). They 
are sometimes confined to the achenial angles, the intermediate 
areas bearing glands. Archer refers to such achenial hairs being 
bifid at the apex as existing very extensively among the Compos- 
itæ (Proc. Linn. Soc., 1861, p. 17), and Kraus briefly speaks of 
them (Pringsheim’s Jahrbücher fiir Botanik, 1866-7). In Town- 
sendia they diverge at the tips so muchas to become recurved 
(Fig. 7). As some species of this genus have glabrous achenes 
Professor Asa Gray has made the presence or absence of such 
hooked hairs the ground of splitting the genus into sections. We 
now see that such distinction depends on the greater or less devel- 
opment of a structure mages ee to all the Asteroids and to 
VOL. XVII.~—No. i 
