409 
coarsely and deeply serrate with long spreading teeth, the terminal teeth not longer 
than the lateral: flower clusters 2 in each axil, small and loose,—Corpus Christi, 
and wet ravines above E] Paso. 
5. U. chamedryoides Pursh. Slender, 1.5 to 7 dm. high, with sparse stings: 
leaves ovate and mostly cordate, the upper ovate-lanceolate, coarsely serrate- 
toothed: tlower-clusters globular, 1 or 2 in each axil and spiked at summit, 
(U. purpurascens Nutt.)—Alluvial shaded soils, central, southern and western Texas. 
8. BOHMBERIA Jacq. (FALSE NETTLE.) 
Stingless herbs, with moncecious or diccious clustered flowers, the 
sterile much as in Urtica, the fertile with a tubular or urn-shaped 
entire or 2 to 4-toothed calyx, elongated and awlshaped style stig- 
matic and papillose down one side, and the elliptical achene invested 
by the dry and persistent compressed calyx. 
1. B. cylindrica Willd. Perennial, smoothish or pubescent and more or less sca- 
brous, with simple stem 3 to9dm. high: leaves rarely alternate, ovate to ovate-oblong 
or oblong-lanceolate, pointed, serrate, 3-nerved; stipules distinct; petioles short or 
elongated: flowers dicious, or the two kinds intermixed, the small clusters densely 
aggregated in simple and elongated axillary spikes; the sterile interrupted; the 
fertile continuous, frequently leaf-bearing at apex.—Moist, shady grounds, western 
Texas. 
9. PARIETARIA L. (PELLITORY.) 
Homely diffuse or tufted herbs (not stinging), with 3-ribbed leaves, 
no stipules, monceciously-polygamous flowers in the same involuerate- 
bracted cymose axillary clusters, the sterile much as in the last, the 
fertile having a 4-parted and nerved calyx, a slender style (or none), a 
pencil-tufted stigma, and an ovoid ovary. 
1. P. Pennsylvanica Muh! Low annual, simple or sparingly branched, minutely 
downy: leaves oblong-lanceolate, thin, veiny, roughish with opaque dots: flowers 
shorter than the involucre: stigma sessile.-—Extending from New England to cen- 
tral Mexico. 
2, P. debilis Forst. Taller, pubescent with straight and hooked hairs inter- 
mixed: stems much branched, pellucid: leaves ovate, mostly acuminate, roughened 
with elevated dots: clusters loose, spreading: tlowers as long as the involuere. 
(P. Floridana Nutt.)—Rocky places, from the upper Rio Grande to central Texas, 
PLATANACER, (PLANE-TREE FAMILY.) 
Trees, with watery juice, alternate palmately-lobed leaves, sheathing 
stipules, moncecious flowers destitute of calyx and corolla and im sepa- 
rate and naked spherical heads, the fruit merely clavate 1-seeded 
nutlets furnished with a ring of bristly hairs about the base. 
1. PLATANUS L. (SycaMorE. BUTTONWOOD.) 
Large trees, with the bark deciduous in broad thin brittle plates, 
the dilated base of the petioles inclosing the bud of the next season, 
sterile flowers of numerous stamens with clavate little scales intermixed 
and very short filaments, fertile consisting of inversely pyramidal 
ovaries mixed with little scales, the simple rather lateral style awl- 
shaped or filiform, and coriaceous nutlets. 
