180 ~~ BOTANY. 
the teeth tipped with longer spines than are found on the inter-dental 
margins; heads many, 1-14’ in diameter, the subtending bracts spiny- 
margined and tipped; outer involucral scales strongly ciliate-fringed ; inner 
ones less so, except at the tip, which has a small, oblong, ciliate, spine-tipped 
appendage 1-2” long and half as wide; flowers light. yellow—Twin Lakes, 
Colorado (460). 
CrenTAUREA* AmerrIcANA, Nutt.—Erect, 4°, smooth; leaves sessile, 
entire, glabrous or nearly so, but with margins slightly ciliate; heads, 
including the long purple rays, 4’ in diameter; outer scales of the involucre 
very short and tipped with a lanceolate, brown, pectinate-ciliate appendage 
as long, or longer than the scales, the inner series becoming regularly longer 
and more scarious, the appendage remaining same size as in the outer 
series; pappus of rigid, similar, roughish bristles—Chiricalhua, Southern 
Arizona (527). 
Pereziat Wricatu, Gray (Pl. Wright. 1, p. 127).—“‘Smoothish; the 
leafy herbaceous stem 2° high, from a perennial root; leaves thin, mem- 
branaceous, oblong-ovate, spinulose-denticulate, the larger doubly dentate, 
sessile and at base often auriculate; compound corymb polycephalous ; 
heads 8-10-flowered, sub-fasciculate, involucre viscid sub-puberulent, scales 
hardly in 3 series, oblong and rather obtuse; achenia glandular, the soft 
white pappus of delicate bristles. Well distinguished by its membranaceous 
leaves and small heads” Not having the plant, I have quoted the original 
description.—Arizona. 
Perezia nana, Gray (Pl. Fendl. p. 111).—2- 19! high, the single- 
headed leafy branches erect from a woolly, creeping root; leaves thickish, 
strongly reticulate, ovate or a little cuneate at base, sessile, very irregularly 
toothed, teeth spiny or mucronate-tipped from the produced nerves; heads 
* CENTAUREA, L.—Heads many-flowered ; ray-fl tly] J sterile, sometimes wanting; 
involuecre various, imbricated. Receptacle setose. Achenia compressed. Pappus occasionally wanting 
or nearly so, but usually composed of scabrous filiform bristles, in one or more series, the inner often 
smaller and somewhat conunivent.— G. 
t PEREZIA, Lagasca.—“ Head snrerhl-pane Rowe’: ; the flowers all perfect. Involucre turbinate 
or campanulate; its scales imbricated, lanceolate or oblong, mostly chartaceous. Teceptacle flat and 
naked. Corolla with a slender tube and bilabiate limb; the outer lip much longer and 3-toothed; the 
inner 2-toothed or 2-cleft. Anthers with long nuked tails at base, and a lanceolate terminal appendage. 
Akenes gi Gia terete or slightly angled, often obscurely narrowed at apex, commonly glandu- 
lar. of copious scabrous capillary bristles.—Herbs; with alternate and mostly rigid leaves, and 
solitary or consis paniculate heads of purple or white Kowc: ”—GRAY, Fl. Cal. 1, p. 422. ’ 
