OF ARTS AND SCIENCES : FEBRUARY 13, 1872. 401 



447. Polygonum aviculare L. A native form of the species? 



448. Polygonum ramosissimum Michx. ; a tall, yellowish form. 



449. Polygonum tenue Michx., with a larger-flowered variety 

 peculiar to the western side of the continent, P. racemosum Nutt. herb. 

 450. A low form, with more crowded and showy blossoms. 451. A 

 somewhat similar form. 452. An undetermined, probably undescribed 

 species of this section. 



453. Polygonum coarctatum Douc;!. in Hook. Fl. Bor.-Am. 

 2, p. 133. 



454. Polygonum Convolvulus L. Apparently native. 



455. Comandra ujibellata Nutt. Quite like the Eastern plant. 



456. Phoradendron flavescens Nutt., var. villosum Engelm. 

 P. villosum Nutt. and P. tomentosum Engelm. 



457. Arceuthobium abietinum Engelm. n. sp. ; male specimens. 

 458. Female specimens. On Abies grandis, Willamette Valley. 



459. Callitriche marginata Torr. Bot. Whippl. p. 79. 



460. Callitriche verna L. 



461. Callitriche Bolanderi Hegelm., apparently. Stigmas 

 elongated. 



46 l a . Callitriche autumnalis L. With young fruit. 



462. Eremocarpus setigerus Benth. Bot. Sulph. p. 53, t. 26. 

 Croton setigerus Hook. Fl. Bor.-Am. 



463. Euphorbia glyptosperma Engelm. in Bot. Mex. Bound, 

 p. 187. 



464. Euphorbia serpyllifolia Pers. : a narrow-leaved form, 

 with distinctly scrobiculate seeds. 465. A broader-leaved form, with 

 seeds obscurely scrobiculate. 



466. Celtis reticulata Torr. ; Nutt. Syl. 1, t. 39. In fruit. 



467. Castanopsis chrysophylla A. DC. Castanea chyrsophylla 

 Dougl. in Hook. Fl. Bor.-Am. 2, p. 159. 



467 a . Corylus rostrata Ait., var. Californica A. DC. Beak 

 of fruit much shorter than in the Eastern species. 



468. Myrica Californica Cham. & Schlecht. ; Hook. Fl. Bor.- 

 Am. 2, p. 160. 



flowering spikelet. Leaves 2-3 lines long, half a line wide, thickish, the point 

 bayonet-like, those of the flowering spikelets nearly concealed by the sheaths. The 

 spikelets are 6-10 lines long and very numerous, silvery or tawny, witli the con- 

 spicuous sheaths contrasting beautifully with the chestnut-colored bark of the 

 branches. — Very dry rocky hills east of Napa Valley, California, Brewer, Bolander." 

 VOL. VIII. 51 



