Parietaria. PLATANACE.E. 65 



* * Annuals: Inflorescence of muKjled nude and feniaJe flowers, iisuaUi/ shorter 

 tJtan tlie 2>etioles : stipules verij snudl. 



4. IJ. urens, Linn. Slender, erect or ascending, a foot or two lii.^li, with short 

 lateral brancldels, leafy throughout, with scattered hairs or nearly glabrous : leaves 

 thin, ovate or ovate-oblong, an inch or two long, coarsely and incisely toothed ; 

 stipules small, free : flower-clusters mainly pistillate, rather close and nearly sessile 

 or more loosely panicled : fruiting sepals ovate, hispid on the margin, usually with 

 a single lateral bristle : akene a liiie long. 

 An introduced weed from Europe. 



2. HESPEROCNIDE, Torrey. 

 Distinguished from the last grouj) under Urtica only by the pistillate perianth, 

 which is a membranous compressed oblong-ovate sac, with a minutely 2 - 4-toothed 

 orilice. — Annual herbs ; only two species, the second belonging to the Sandwich 

 Islaiids. 



1. H. tenella, Torrey. Slender and weak, often a foot or two high, simple or 

 branched, sduiewhat hispid with branching hairs and bristly : leaves tliin, ovate, 

 ^2 to \h inches long, on short slender petioles, obtusely serrate : flower-clusters loose, 

 shorter than the petioles : perianth thin, hispid with hooked hairs, J to f line long 

 in fruit : akene membranous, striately tuberculate with minute rough points. — 

 Pacif. R. Eep. iv. 139 ; Weddell, DC. Prodr. xvi\ 68. 



In the shade of rocks, Napa County and southward; Guadalujie Island, Palmer. 



3. PARIETARIA, Toum. Pellitoky. 



Flowers perfect and pistillate, in axillary cymose clusters, involucrate-bracted : 

 perianth in the perfect flowers 4-parted, in the pistillate tubular-ventricose and 

 4-cleft with connivent lobes : style slender or none : stigma spatulate, recurved, 

 densely tufted : akene ovoid, shining, enclosed in the dry brownish nerved calyx : 

 albumen scanty. — Low annuals (our species), unarmed ; leaves alternate, entire, 

 3-nerved, without stipules. 



A widely tlistrilnited genus of 8 or 10 species, two of them American. 



1. P. debilis, Forster. Very slender, 3 to 12 inches high, usually diffusely 

 branching from the base, somewhat hispid : leaves small, broadly ovate, obtuse, 

 rounded at base or abruptly cuneate, 2 to G lines long or more, about equalling the 

 slender petioles : clusters few-flowered ; bracts linear or narrowly oblong, short (i 

 to 1 line long), about equalling the flowers : akene \ line long. — Weddell, DC. 

 Prodr. xvi\ 235*^ 



Southern California, from Santa Barbara to San Diego, and eastward in various forms across 

 the continent, southward to Chili, and nearly everywhere within a like broad zone arounil the 

 globe. 



P. Pennsylvanica, Muhl., is a more northern species, common in the Atlantic States and col- 

 lected as far west as the mountains of N. E. Nevada. The leaves are lanceolate, more attenuate 

 at base, and often 2 inches long or more ; bracts longer and exceeding the flowers ; akene some- 

 what larger. 



Order LXXXV. PLATANACE^. 



Monoecious trees, with flaky bark, alternate pahnately nerved and lobed leaves, 

 with sheathing deciduous stipules, and the holhnvcd petiole covering the l)ud ; 



