OF Hacchakis genist?:lloides OSO 



It is difficult to determine the function of cither kind of hairs, 

 if tiiey have anw In the younger parts, where alone the hairs are 

 plentiful, they are often entirely embedded in the wax. The gland- 

 cells are usually thickly covered, while occasionally part of the 

 end-cell of the whip-hair protrudes beyond. Of what use can a 

 secretion be, the escape of which is entirely prevented? In the 

 cases among the Compositae in which the whip-hairs are found, 

 they are usually present as Vesque shows as a tomentum. Prob- 

 ably here, as in Chrvsoiiia paiuiJJoscnlosa described by Professor 

 Lloyd, they are functionless.* 



The stojuata are evidently of a motile tvpe (/. 7). They are 

 provided with distinct accessory cells, so that this plant adds 

 another to the list of compo.sites so pro- 

 vided, although Benecke f declares these 

 cases rare. Both upper and lower walls 



taper into very finely pointed ridges. No Fif'-- 7- Stoma from 



/•!• LL J- ju Stem of Baccharis geni- 



trace of a hmge has been discovered by me, „ . , * 



=* . . stelloides. 



but the cutin seems thinner at the junction 



of the guard and accessory cell. The accessory cells raise the 

 stomata somewhat above the level of the epidermis. They are 

 more exserted on the stem than on the wing. 



The Stem 

 In the plants examined, the stem varies in thickness from i to 4 

 mm. In the younger portions, to about 12 cm. from the tip, the 

 supporting tissue consists largely of sclerenchyma, the wood proper 

 being confined to a very narrow ring about 25// in diameter. 

 The masses of bast-fibers are found at intervals around the stem, 

 but the six largest masses are opposite the three wings and half way 

 between them respectively (/. 8). These bast-fibers are strongly 

 lignified, so that they give a much more pronounced reaction with 

 phloroglucin than the young wood-ring itself. The lignification 

 of the bast-fibers begins very near the growing tip ; signs of it 

 can be found at the distance of 1.5 cm. therefrom. This early 

 acquisition of lignin would seem to indicate a very slow rate of 

 growth — a point which will be recurred to presently. 



* Lloyd, F. E. Anatomy of Chrysoma pauciflosculosa. Bull. Torrey Club, 28: 

 445. Au 1901. 



fBot. Zeit. 50: 570. 1892. 



