Siimihin. GRAMINI'L'E. 289 



involuti'. Tlu' tiiiilc awn scpamtcs tlio f,'.>nii.s fioiii S/ipcr, wliirli it in otlicr iosiii>ct.s much re- 

 scinl.K's. Ill the Kastciii States Aris/itla is ivpioscntod by about a <b>ziMi si.cics, wliile S/ipa has 

 but tliivc ; ui.oii tlie Tarilir. Coast tliesc ininibcis are very nearly level scd. In tlie division of 

 tlie f,'eiiuH, those having tlie jieisisteiit stiaij^ht awn continuous with and divided down to the 

 palet are plaeed in the scetion Cluihai,,. Those with the aw^n divided above and twisted below 

 to lonu a stipe, which is articulated with the palet and caducous, loriii the section Arlhral/icrum, 

 which is regarded by some as a genus. 



1. A. bromoides, IIUK. Culms fix.iu 3 to 12 inches lii^^li, foimiiig close tufts, 

 sleiulor an. I often gcnicniljite below : radical loaves few and short ; those of the culm 

 two, 1 or 2 inches loii<,', involute-setaceous and rather rigid, smooth below, minutely 

 scabrous above; ligule minute, fringed; slieaths shorter than the internodes : pani- 

 cle 1 to 3 indies long, spike-like, somewhat secund, the rays solitary or clustered, 

 branched nearly to the base : spikelets purplish, 4 to 5 lines long, on shorter i)edi- 

 cels : glumes narrow, mucronate, scabrous on the back, the lower about 2 lines long, 

 the upper twice its length : lloret mostly e.pialling the upper glume, its short callus 

 with brief, very Avhite hairs; lower jiahit greenish with numerous dark purple 

 blotches, smooth except on the scabrous midnerve ; middle awn rather longer than 

 the palet, the lateral ones somewhat shorter, idl minutely scabrous ; upper palet very 

 short, scarcely exceeding the ovary. — .\ov. (len. & .Spec. i. 122. A. Jisperm, var. 

 bromoides, Trin. & liupr. 8tipace;c, 130. 



Colorado Desei t {SclioN) ; Sail Diego (llo/aiulrr) ; Sonoia, New Mexico and Texas ; Quito. A 

 variable species, lorms of which have l)een described under several names ; these have been brouglit 

 togethi'r by Trillins and Kupieclit as varieties of one species, to which they gave a new name 

 A. di.'^/ifrxii. In this case it seems projier to continue one of the older names. The plant i.s 

 probably an annual, though none of the sjx-cimcns have roots. The same tuft has culms from 3 

 inches to a foot high ; in tiie shorter ones the base of the panicle is includ(-d, but in the taller it 

 is long e.xserted. In the young plant the panicdes are dark purple ; in older specimens, they be- 

 come light brown. 



2. A. Californica, Thurlier. (,'ulms 5 to 10 inches high, very densely tufted, 

 geniculate below and branched above, i)ubescent, especially at the nodes : leaves 

 involute, jiubesceut above, scabrous below, the radical from 1 to l.V inches long, 

 those of the culm shorter, the u|)permost minute or reduced to a mere sheath ; ligule 

 a fringe of hairs ; sheaths shorter than the internodes, loose, striate, pubescent or 

 hirsute : panicle 1 or 2 inches long, racemose, few-llowered, the lower spikelets in 

 pairs (one sessile, the other short-pedicelled), the upper solitary : glumes scabrous on 

 the. keel, la(;erate-fringeil at apex, usually purple with wiiito margins, the lower 4, 

 the upper C) lines lung: (huvt sliorter than the lower glume, with a conspiciuuis 

 white-hairy callus one-third its length ; lower palet miinitely scabrous, especially 

 above, pale greenish and marked with purplish-blaek blotches, the upper palet about 

 one-fourth as long ; awns about e.pial, very slender, minulely siiabrous, 1 .1 to 2 inches 

 long, twisted below into a slender stipe (5 to 8 lines long), which is articulated with 

 the upper palet and deciduous at maturity. — IJolander in Trans. Calif. Agric. Soc. 

 1804 -G5, 134, without descri|)tion. 



Colorado Desert (Scfiott) ; Fort Mohave, Ompcr. Apparently nn annual, which by its numerous 

 branches and long awns forms a complex tuft. It is the only species of tlie se.-tion with articu- 

 lated, caducou.s awns (^Arthra/hermn) thus far found in North America. According to Mr. Sobott 

 it is known to the Mexicans ns Zacafc dc lirhir, " Ilare'.s-grass." 



27. SPARTINA, S.direb. Conn-GnAs.^. 

 Panicle of mostly erect racemed spikes. Spikelets crowded in two rows upon one 

 side of a triangular rhachis, subsessile, l-flowered with no rudiment, much flattened 

 laterally. (Humes rigid, more or less rough bristly on the strongly compressed keel, 

 acute or short-awtied. Floret sessile, shorter than the uiiper glume. Lower palet 

 membranaceous or chartaceous, awnless, the upp(^r slightly longer. Scales none. 

 Stamens 3. Ovary smooth : styles very long, more or less united below ; stigmas 



