105 



A SYNOPSIS OF THE SPECIES OF ISOETES. 



By J. Ok Baker, F.R.S. 



(Concluded from p. 4(5.) 



Group 3. Amphibia .—Species inhabiting waters where they are 

 liable to be left dry. Leaves furnished with accessory bast- 



* bundles and abundant stomata. A few small membranous 

 leal- bases occasionally persistent. 



p W \ S?? E ?' En g elm - iu Amer. Bot. Gaz., hi. (1878), 1.— 



Rootstock 2-lobed. Habit of I. melanopoda; said to tie dioicous. 

 Reaves 8-12, 3-7 m. long, moderately firm in texture, tapering to 

 tne point, furnished with stomata and accessory bast-bundles, 

 sporangia globose or oblong; veil very narrow. Macrospores 

 larger than m melanopoda, marked with distinct or rarely confluent 

 tubercles. Microspores spinulose. 



Hab. Limestone gap, near the watershed between the Red 

 itiver and Arkansas River, Western United States, Q. D. Butler. 



a. 102.<&$ 



-___, v . y^t»j , ^uiicu in jluui. juui. ouc, rraiice, 



ootstock deeply 2-lobed. Leaves 15-50, i-1 ft. lorn* 



43 un. diam. at the middle, moderately firm in texture, opaque, 



)TlT S J, the point ' fnniisli ed with stomata and a few accessory 

 oast- bundles, narrowed suddenly into the dilated base. Sporangia 



SSbnVL; ° b i° ng ',*-3 in « lo »S> often bright chestnut-brown, 

 opiousiy dotted ; veil very narrow. Macrospores small, nearly or 

 quite smooth beyond the ribs. Microspores spinulose. 



Kfn+T # bha S ow P° nc l3 and damp prairies, Western United 

 Mates, from Illinois to Iowa and Texasf 



2 InK 1 ! L J ngelma nni, A. Br. in Flora, 1846, 178.— Rootstock deeply 

 oS * 1_li iu diam ' Habit of stout L ^oiistris. Leaves 

 evppJ , ; ° • a foot lon 2> * lin - diam - at middle, diaphanous, pale 

 been, tapering to the point, furnished with accessory bast-bundles 



narrnw Pl ° U a stomata > the edge decurrent from the base, short and 

 narrZ' ,°P oran & e lai "ge, pale, oblong, unspotted; veil very 

 M,V™!' Macros P°res middle-sized, white, honeycombed all over. 

 Microspores smooth or nearly so. 



Enri^i . Po £- ds m the Northern United States from New 

 with inn 1 Missouri. Var. valid*, Engelm., is a large variety, 



snorpi « ii eaves ' X *~ 2 ft - lon S> a broader veil, both kinds of 

 f *es smaller, and microspores spinulose. 



I otJ' S^?^ 11 ' A - Br - ; Er >S el m. m Amer. Nat., 1874, 215; 

 20-60 qlpf U Herb - '— Rootstock faintly 2-lobed. Leaves 

 texture l g ' * lin * diam * at ihe middle, moderately firm in 



point wit? +1 greeu > Paque, 8-angled on the back, tapering to the 

 ^e ecW 1 6 accessor y bast-bundles and numerous stomata, 



small b tiil iT eDt from tiie base snorfc aud narrow - Sporange 

 densely™- ,, lon g; Tei l complete. Macrospores middle-sized, 



Hab A y ^anulated. Microspores papillose. 

 of I me'la ^ mea ^ows and edge of ponds in Oregon. Habit 



p 



