Parieturia. PLATAN ACE.E. 



65 



■■1= * AiDiuals: iiifovescenre of mbujled mule and female Jioicers, im(nlli/ shorter 

 than the 2Jetioles : stijmlcs veri/ small. 



4. U. urens, Linn. Slender, erect or ascending, a foot or two liigli, with short 

 lateral brancldet.s, 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 : llowerclusters mainly pistillate, rather close and nearly sessile 

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

 a single lateral bristle : nkene a line long. 

 An intnuhioi'il weed from Kuroi)p. 



2. IIESPEROCNIDE, Tonoy. 

 Distinguished from the last group under Urtica only by the pistillate perianth, 

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

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

 Islands. 



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

 branched, somewhat hispid with branching hairs and bristly : leaves tiiin, ovate, 

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

 shorter than the jjctioles : perianth thin, hispid with hooked hairs, \ to | line long 

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

 Pacif. R. Kep. iv. 139 ; Weddell, DC. Prodr. xvi'. 68. 



Ill the shade of rocks, Napa County and southward; Guadalupe Island, Palmer. 



3. PARIETARIA, Tourn. Peuutorv. 

 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 sjjatulate, recurved, 

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

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

 3-nervcd, without .stipules. 

 A widely distiiliuted 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, 

 rouutled 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 (^ 

 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 Cliili, and nearly everywhere within a like broad zone around the 

 globe. 



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

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

 I at base, and often 2 inches long or more ; bracts longer and e.xceeding the flowers ; akene some- 

 j what larger. 



Order LXXXV. PLATANACE^. 



Monoecious trees, Avith flaky bark, alternate palmately nerved and lobed leaves, 

 with sheathing deciduous stipules, and the hollowed petiole covering the bud ; 



