369 
+++ Fruiting bracts waited, orbicular, compressed, indurated, surrounded by a double 
herbaceous toothed margin, sides carinate. 
3. A. elegans Dietrich. Erect, slender, 1.5 to 3 dm. high, branching, leafy: leaves 
oblanceolate to linear, 1 to 2 em. iong, obtuse or acute, entire or with few teeth near 
the apex: male clusters subterminal or in slenier naked spikes: fruiting bracts 
3mm. broad, very shortly pedicelled, the margins radiately toothed. (Obione radiata 
Torr. Bot. Mex. Bound. 183. 0. elegans, var.? radiata Torr,, in part.)—Western Texas. 
—~+++ Fruiting bracts rhombic-orbicular, indurated, subcompressed, 4 to 8 mm. long, 
usually conspicuously appendaged and the foliaceous margin toothed and undulate: 
leaves triangular and subhastate, the lower opposite. 
4, A. argentea Nutt. Usually low (1.5 to 4.5 em. high), diffusely branched, gray- 
ish-scurfy or nearly glabrous: leaves petioled: male flowers in dense and short 
spikes: bracts short-pedicelled.—Vatiey of the Pecos. 
5. A. expansa Watson. Resembling the last, but stouter, erect, with more 
widely spreading virgate branches: leaves thinner, sessile: staminate spikes elon- 
gated, leafless above: fruiting bracts more compressed, and the sides more often 
unappendaged and strongly reticulated, (Obione argentea Torr.)—Comumon on the 
alkaline flats of the Pecos and in the valley of the Rio Grande below San Elizario. 
** Perennials, shrubby, densely appressed scurfy. 
+ Fruiting bracts with a toothed margin, aud the sides usually more or less appendaged, 
somewhat spongy. 
++ Fruiting bracts rather large, slightly compressed: leaves over 12 mm. long, alternate. 
6. A. Nuttallii Watson. Erect, 3 to 9 dm. high, branching from a shrubby base: 
leaves narrowly oblong-spatulate to oblanceolate, 12 to 50 mm. long, cuneate at base, 
sessile, entire: fruiting bracts ovate, united to above the middle, the orifice scarcely 
contracted, becoming suborbicular, 3 to 4 mm. long, the sides more or less crested. 
(Obione canescens Moq.)--Valley of the Rio Grande, from E] Paso to Eagle Pass. 
7. A.acanthocarpa (Torr.) Watson. Erect, 3 to 7dm. high, branched, leafy : leaves 
oblong-lanceolate or oblanceolate (often subhastate), 12 to 40 mm. long, acutish, 
cuneate, short petioled, usually undulate, sinuately toothed or entire: flowers dicw- 
cious; the staminate clusters dense in naked terminal spikes; fertile clusters axillary, 
few-flowered: fruiting bracts lanceolate, the linear apex only free, becoming & to 12 
mm. long, the sides strongly appendaged with rigid flattened processes. (Obione 
acanthocarpa Torr, Bot. Mex. Bound, 183, mostly.)--From the Guadalupe to the Rio 
Grande, 
s+++ Fruiting bracts more or less compressed, rather small: leaves numerous, about 6 mm, 
long or less, entire, more or less opposite. 
8, A. Greggii Watson. Slender, 1.5 to 3.5 dm. high: leaves alternate or the lower 
opposite, oblong or spatulate, 6 to 12 mm. long, cuneate at base, mostly sessile: flowers 
in small axillary clusters or slender interrupted nearly naked spikes: bracts united 
only at base, cuneate-orbicular, becoming 3 to 6mm. broad, dentate-margined from 
below the middle, and the convex sides usually tooth crested. (Obione canescens, var. 
and 0. acanthocarpa Torr. Bot. Mex. Bound, 183, in part.) —On the Rio Grande, below 
Presidio del Norte, and the Burrow Mountains. 
9, A. oppositifolia Watson. Woody at base, erect, 3 dm. high, branched: leaves 
thick, 2 to 4 mm. long, mostly opposite, oblong-lanceolate, sessile and broadest at base : 
flowers axillary, sessile, dicecious (?): fruiting bracts united, orbicular, 2mm. broad, 
short-pedicelled, the margin radiately toothed, sides 3-nerved, not appendaged.— 
From Corpus Christi to the Rio Grande. 
