242 
DATISCACEiE. 
Megarrhiza. 
Angels Camp, Calaveras County (Rich, Bigelow) ; near Placerville, Kellogg , Bolcmder. Speci¬ 
mens collected by Fremont, Hulse, and others, in the same region (from the Mokelumne River to 
the Upper Sacramento), may belong here though with the ovary 3- or 4-celled, and in some other 
minor respects different. 
5, M. Guadalupensis, Watson, 1. c.. Nearly glabrous, the inflorescence some¬ 
what pubescent: leaves thin, 3 to 8 inches broad, 3-5-lobed to the middle, the 
lower lobes quadrangular, the upper acuminate, with few short teeth : . racemes 
nearly simple, 4 to 6 inches long: calyx-teeth filiform : Corolla 6 to 8 lines broad: 
fertile flowers without abortive stamens: ovary on a slender pedicel an inch long, 
ovoid, densely covered with short soft spines, 2-celled; ovules 1 or 2 in each cell, 
ascending: fruit ovoid, IJ to 2 inches long, acute above, somewhat pubescent and 
with short scattered stiff spines, usually 2-seeded : seeds subglobose, an inch in 
diameter, attached to the inner side of the cell, the margin smooth. 
Guadalupe Island, on high rocks near the centre of the island, Palmar, 1875. 
Order XLII. DATISCACEJE. 
A very small and peculiar order, chiefly represented, by the following genus of 
only two species. 
DATISCA, Linn. 
Flowers dioecious, sometimes perfect. Calyx of sterile flowers very short, with 4 
to 9 unequal lobes : stamens 10 to 25; filaments short: rudimentary ovary none. 
Pistillate flowers with calyx-tube ovoid, somewhat 3-angled, 3-toothed : stamens 
three, when present, alternate with the teeth : styles 3, bifid, opposite the teeth, the 
linear lobes stigmatic on the inner side. Capsule oblong, coriaceous, 1-celled, open¬ 
ing at the apex between the styles. Seeds very numerous and small, in two to 
several rows upon the 3 parietal placentae : embryo cylindrical, in the axis of small 
albumen. — Smooth stout perennial herbs; leaves unequally pinnatifid, with coarsely 
toothed lanceolate segments, the upper scarcely lobed; flowers axillary, fascicled, 
nearly sessile. 
Only two species known, one native of W. Asia, the other of Galifornia. 
1. D. glomerata, Benth. & Hook. Erect, 2 or 3 feet high or more, branching : 
leaves ovate to lanceolate in outline, acuminate, 6 inches long, the numerous floral 
ones shorter and more narrowly lanceolate : flowers 4 to 7 in each axil of the elon- 
. gated leafy raceme, the fertile mostly perfect: anthers nearly sessile, 2 lines long : 
styles longer than the ovary: capsule oblong-ovate, 3 or 4 lines long, slightly nar¬ 
rowed toward the truncate triangular 3-toothed summit. -— Gen. PL i. 845. Tri- 
cerastes glomerata, Presl, Eel. Hsenk. ii. 88, t. 64; Lindl. Veg. Kingd. 316, fig. 
On stream-banks from Napa County to San Bernardino, and in the foot-hills of the Sierra Nevada 
from Amador to Tuolumne County. 
Order XLIII. CACTACEiE. By Dr. George Engelmann. 
Green fleshy and thickened persistent mostly leafless plants, of peculiar aspect: 
globular or columnar, tuberculated or ribbed, or jointed and often flattened, usually 
armed with bundles of spines from the “ areolae” which constitute the axils of the 
(mostly absent) leaves. Flowers with numerous sepals, petals, and stamens,, usually 
