200. (Fig. 192.) TURNERA. Damiana.

Fl. ex. 30.

The leaves of Turnera diffusa var aphrodisiaca Ward, and several other species of Turnera, Turneraceæ.

Green; soon turning brown.

Slightly aromatic.

Somewhat pungent.

Stomata on lower surface only. Vertical walls of epidermal cells somewhat wavy, thin; cuticle thick with linear markings. Simple, single-celled, somewhat bent and coiling, thick-walled trichomes with cuticular markings. Abundant tissue with deep reddish brown resin. Numerous aggregate crystals of calcium oxalate.

Compare with T. diffusa, T. microphylla, and Aplopappus discoidea (false damiana).

201. (Fig. 193.) ULMUS. Slippery Elm. U. S.
Moderately fine to quite fine.

Elm bark, E. Ulmenrinde, Rüsterrinde, G. Orme fauve, Orme
Champêtre, Fr.

The inner bark of Ulmus fulva Michx., Ulmaceæ.

Very light brown.

Odor of fenugreek.

Very mucilaginous; tasteless.

Bits of the outer bark are usually present, therefore brown cells may be found, no sclerenchyma. Inner bark parenchyma cells comparatively small, thin-walled, rather closely united; porous, elongated sieve tube like elements, and medullary ray tissue plentiful. Numerous very characteristic prismatic crystals of calcium oxalate; they occur in twos, each crystal having a hilum-like dot in the middle. Enormous mucilage cells. Starch deficient. Numerous bast fibers with thick walls.

Very frequently adulterated with flour. Compare with U. campestris and U. Americana.

Fig. 193. ULMUS.

a. Inner bark parenchyma.

b. Medium sized mucilage cell.

c. Characteristic crystals (twin crystals) of calcium oxalate.

d. Bast fibers.

e. Porous, tracheid-like elements.

202. (Fig. 194.) UVA URSI. Uva Ursi. U. S.

Fl. ex. 30.

Bearberry leaves, E. Bärentraubenblatter, G. Busserole, Raisin d'ours, Fr.

The leaves of Arctostaphylos Uvaursi Sprengel, Ericaceæ.
Greenish brown.

Somewhat fragrant.

Very astringent, bitter.

Epidermal cells, polygonal, upper larger than lower; large orbicular stomata on lower surface only. Cuticle thick, yellowish. Leaf parenchyma cells with oil globules. Prismatic crystals of calcium oxalate. Thick-walled parenchymatous tissue.

Ash 3.25 per cent.

Adulterated with leaves of cowberry, red whortleberry, sand myrtle, box, trailing arbutus, and Chimaphila.