ENGELMANN — NORTH AM. SPECIES OP JUNCUS. 459 



R. Brown, J. Richardsonius, Rcem. & Schult., J. pelocarjms, 

 Gray Man. ed. 1, 507, in part, non Me}'., J. articulatus, var. 

 peloca?'pus, Gray Man. ed.2, 482, in part; J. elongatus, Vasey, 

 in herb. — This form ought, perhaps, not to be separated from 

 the last species, but with us it is easily distinguished, and oc- 

 cupies a distinct geographical range; I, therefore, keep them 

 apart for the present, and leave the final decision to the botan- 

 ists of Europe, where both forms are much more abundant. — 

 With us this species is confined to the northern and western 

 parts of the continent, where it is usually found on the sandy 

 or gravelly banks of lakes or streams; from Lake Champlain, 

 Robbins, Macrae, and Seneca and Ontario lakes, Sartioell, 

 where it meets the eastern, J. articulatus, northward to the 

 Hudson Bay regions, Drummond and others, and the Arctic 

 shores, and westward along the great Lakes to Detroit, JBige- 

 low, Herb. norm. 51, northern Illinois, Vasey, and the upper 

 Platte, Hayden, Colorado, Hall & Harb. 558, and beyond the 

 Rocky Mountains toward Fort Colville, Lyall. 



Stems erect from a creeping rootstock, 10-18 inches high ; 

 branches of the meagre panicle, at least in the larger speci- 

 mens, strictly erect and much elongated, greenish and light 

 brown ; sepals oblong, obtuse, outer ones mucronate or cuspi- 

 date, equal to, or exceeding, the rounded inner ones; stamens 

 same as in last; ovary ovate, with a very short style; capsule 

 as long as, or a little longer than, the sepals, obtuse, mucronate, 

 incompletely three-celled ; seeds very similar to last, but usu- 

 ally more slender, oblanceolate and acute at both ends, rarely 

 obtuse at the upper one, 0.30-0.35 line long. — The alpine form 

 of this plant, the original type of Villars, is found in our Arc- 

 tic regions, and is only a few inches high, bearing very lew 

 almost black heads, and has the slenderest and longest seeds. 

 The ordinary American plant is distinguished from the usual 

 European form by its lower stems, still stricter panicle, and 

 paler flowers and fruit. Fries has sent absolutely the same 

 from Sweden, formerly as J. sylvaticus, and as J. acutiflorus, 

 and later as J. alpinits, var. i/isignis, which name may be re- 

 tained for it. 



35. J. dubius, n. sp.: rhizomate crasso horizontali; caulibus 

 (l£-3-pedalibus) erectis cum foliis tereti-compressis; pa- 

 nicula supradecomposita patula; capitulis pauci-(6-10)fioris 

 stramineis; floribus subsessilibus; sepalis lauceolato-subulatis 

 acutissimis aaqualibus stamina six fere duplo superantibus; an- 

 theris linearibus filamento sublongioribus ; capsula lineari- 

 prismatica acutata uniloculari exserta ; seminibus obovatis 

 utrumque apiculatis areis lineolatis reticulatis. 



Forming large tufts in wet granitic sand in Clark's meadow, 

 near the Big Tree Grove, Mariposa, California, at an altitude 

 of 6,500 feet, H. Bolander, fl. & fr. in July; Cal. State Surv., 



[April, 1868.] 30 



