ANATOMY OF SPARTIXA. 289 



fill-rows, which aw L'-clcrt at l)<)ll(nii hy Ili<' low i-idges of lli«* siiiallc 

 nerves. 



EpiderDiis: Ventral willi cells much smallrr and riiinn<'r-wallc<i 

 than on the dorsal surface; stoniala on <'ach side of the bottom of 

 tlie furrows, somewhat ijrominent; many of the epidermal cells 

 extended into short, rather thin-walled, erect, unicellular i)ai)illae 

 with broad, rounded or truncate summits, and, especially at tlio 

 summit of the ridges, into longer, sharp-pointed, thick-wuUed, erect, 

 piickle-like hairs; typical bnlliform cells nom,', 1 nit at the bottom of 

 each furrow a gronp of nsually 3 large epidermis cells, which are 

 probably functionally homologous. Dorsal with tliic'k, porous walls, 

 which, in the rows containing stoniata, are unevenl}^ thickened so as 

 to appear wavy, 1 or more often 2 short cells alternating with the 

 longer ones; cuticle thick; stomata in very shallow furrows; hairs 

 and pai^illae none. 



Suhepidernial stereome not as strongly developed as in most of the 

 strand grasses, in small grou^Ds on the dorsal side of each nerve; in 

 flattened sufjporting strands at the summit of each ventral rib and 

 extending some distance down its sides; and in comparatively small 

 strands in the leaf margins. 



Chlorophyll chiefly in the j)arenchyma sheath of the mestonn^ Inin- 

 dles, Avith a "bridge" of small-celled chlorenchyina connecting each 

 two neighboring sheaths; palisade none. 



Colorless parencliyma filling the ventral ribs abov<^ the mestome 

 bundles where it interrupts the ijarenchyma sheath, a few cells also 

 interrui^ting the parenchyma sheath on the dorsal side. 



Mestome bundles surrounded l)y a mestome sheath whose walls 

 (esi)ecially the inner) are much thickened only on the leptonui side 

 of the larger nerves; parenchyma sheath (enveloping tlie mestome 

 sheath) containing chlorophjdl, continuous about the smaller nerves, 

 interrupted by colorless i^arenchyma above and l)elow the larger ones; 

 mestome i)arenchyina (thick- walled) in a single layer between the lep- 

 tome and the hadrome of the larger bundles. 



Spartina stricta (Ait.) Koth.' 



Leaf conduplicate when dry, not furrowed on the dorsal surface, 

 deei)ly furrowed on the ventral side, the funows aciii*-, I lie inter- 

 vening ridges broad and truncate at summit. 



Epidermis: Ventral with cells nari'owci- and not s<> liigli as on 

 the dorsal surface, the walls as in .S'. jxdcns^ except that the outer 

 wall of each cell is covered with silicilied papillae; stomata on eacli 

 side of tlu^ bottom of the furrows; hairs none; typical bulliform <'ells 

 none, but 1 to 3 epidermal cells at bottom of each Ncntral furrow 

 somewhat larger than the others and probably functioning as bulli- 



' Although this species belon-^'s to the salt marsh, it is described liere for the 

 sake of convenient comparison with theoth rGram neae. Compare Duval-.Touve, 

 Histotaxie, pi. .18, jig. r>. The Ocr icoke plant is nearly o£ the typical form. 

 2965 3 



