Allspice stem hairs (Plate 7, Fig. 2) have smooth walls. The cell cavity is reddish-brown. The hair is curved.
The hair of senna (Plate 7, Fig. 10) is light greenish-yellow with rough papillose walls. The hair is usually curved and tapering, and it does not have any characteristic cell contents.
PLATE 7
Unicellular Solitary Hairs
1. Chestnut leaf (Castanea dentata, [Marsh] Borkh).
2. Allspice stems (Pimento, officinalis, Lindl.).
3. Cowage.
4. Yerba santa (Eriodictyon californicum, [H. and A.] Greene).
5. Lobelia (Lobelia inflata, L.).
6. Cannabis indica (Cannabis saliva, L.).
7. Anise fruit (Pimpinella anisum, L.).
8. Hesperis matronalis (Hesperis matronalis, L.).
9. Galphimia glauca (Galphimia glauca, Cav.).
10. Senna (Cassia angustifolia, Vahl.).
PLATE 8
Clustered Unicellular Hairs
1. and 2. European oak (Quercus infectoria, Olivier).
3. Kamala (Mallotus philippinensis, [Lam.] [Muell.] Arg.).
4. Witch-hazel leaf (Hamamelis virginiana, L.).
5. Althea leaf (Althæa officinalis, L.).
Cowage hairs (Plate 7, Fig. 3) are lance-shaped, and they terminate in a sharp point. The outer wall contains numerous recurved teeth-like projections. The cell cavity is filled with a reddish-brown contents which are somewhat fissured.
Clustered unicellular hairs occur on the leaves of chestnut, witch-hazel, althea, European oak, etc. In European oak (Plate 8, Figs. 1 and 2) clusters of two and three hairs occur. The walls are yellowish-white, smooth, and the tip of the hair is solid.