315 
mous corymb-like cyme: flowers 1 to 2mm, long, from nearly white to deep rose color 
or rarely yellow.—Mountains and high plains of northwestern ‘Texas. Var. EFFU- 
suM T. & G. has very diffuse and repeatedly divided inftlorescence.—Northwestern 
Texas, but more comm on eastward. , 
17. B. Wrightii Torr. White-tomentose and leafy perennial, much-branched and 
slender: leaves oblong to lincar-lanceolate, acute, 2.5 em. (or less) long: bracts small, 
triangular: involucres solitary and sessile, loosely spicate along the ascending 
branches, 2 to 3mm. long, with rigid acute teeth: flowers white or rose color, 2 to 
3mm. long: achene scabrous above, acute at base.—From the mountains and cations 
of southwestern Texas to Arizona 
18, BE. polycladon Benth. Slender annual, 6 to 9 dm. high, white-tomentose 
throughout, the stem leafy throughout: panicle rather strict and elongated: leaves 
oblong-lanceolate: bractlets villous, with very long delicate hairs: calyx glabrous, 
with segments attenuate at base, the outer fan-shaped, the inner obovate-spatulate,— 
From southwestern Te xas to Arizona and Chiluahun. 
+e t+ lowers not glabrous, 
19. E. coriaceum Coult. & Fisher. Stout subtomentose perennial, about 6 dm. 
high: stem simple, woody below, naked above: leaves oblong-lanceolate, 7 to 10 em, 
long, tapering below to a short clasping petiole, strongly coriaceous, densely tomen- 
tose beneath, silky-villous above: inflorescence 2 or 3 times di- or trichotomous, with 
spreading branches: involucre solitary, sessile, coriaceous, 5 to 7mm. long, with 5 
short and round teeth: flowers yellowish, long-pediceled, densely silky-villous, 7 
to 8 mm, long: ealyx-segments similar, oblong-lanceolate, thickish, with rugose 
margins (EF. Texanum Coult. & Fish., not Scheele.)—Western Texas (Nealley). 
This species seems unlike all others in the very coriaceous texture of the leaves and 
inflorescence, in the very thick involucre strongly nerved within and the lobes 
terminated by a short mucro, and the central involucres pedicellate, 
2. POLYGONUM L. (KNorweEeEb.) 
Ours all herbaceous, flowering through the late summer and early 
autumn, with small and perfect flowers in axillary or spieate or race- 
mose fascicles, mostly 5-parted calyx, with nearly distinet and often 
petal-like divisions, 5 to 8 stamens, 2 or 3 styles, and lenticular or 
d-angled achenes, 
* Flowers in axillary fascicles or spicate with foliaceous bracts: leaves and bracts jointed 
upon a very short petiole adnate to the short sheath of the 2-lobed or lacerate scarious 
stipules: stems striate: calyx 5 or 6-parted, more or less herbaceous: stamens 3 to 8, the 
3 inner filaments broad at base: styles 3: glabrous annuals, 
+ Leafy throughout. 
1. P.aviculare L. Slender, mostly prostrate or ascending, bluish-green: leaves 
oblong to lanceolate, 6 to 20 mm. long, usually acute: sepals scarcely 1mm. long, 
green with pinkish margins: stamens 8 (rarely 5): achene dull and minutely granu- 
lar, mostly included.—Throughout Texas. 
2. P. lacerum HPK. Procumbent and diffuse: sheaths lacerate; leaves linear, 
somewhat fleshy: axils 2-flowered.—Maronillas Creek, western Texas (Harvard), A 
poorly known species of the Andes found in western Texas (fide John K. Small). 
3. P.erectum L. Stouter, erect or ascending, 3 to 6dm. high, yellowish: leaves 
oblong or oval, 1.5 to 6mm. long, usually obtuse: flowers mostly 3mm. long, often 
yellowish, on more or less exserted pedicels: stamens 5 or 6: achene dull, included, 
(P. aviculare, var. erectum Roth.)—Extending into northwestern Texas. Usually asso- 
ciated with No. 1. 
