14 



veins indistinct; fertile spike linear- 

 acuminate, 6" long-, peduncle very slen- 

 der. Ga; Fla; Cal. Synonyms: O. ellepti- 

 cum H & G. — O. Californicum Prantl. — 

 O. vulgatum nudicaule D. C. Eaton (all 

 fide Underwood). 

 O: CALIFORNICUM Prantl. 



Considered by Underwood as O. nudi- 

 caule. 



"Plants small, only 2-6 cm hi; rtstalk 

 cylindric, tuberous, elongated with num 

 large rts; lvs V 2 sheathed at base by the 

 old ones of the previous year; petioles 

 entirely subterranean, 1-2 cm long; 

 sterile lamina 1-2 cm long; 0.4-0.7 mm 

 wide, lanceolate or ovate-acute, rarely 

 obtuse, or apiculate; fleshy, rugose when 

 dxy; basal veins 3, median the stronger, 

 lateral ones branched; transverse vein- 

 lets oblique, forming long narrow areolae 

 with few or no free veinlets near the 

 margin; epidermis wrinkled, cells flex- 

 uous, stomata straight; peduncle arising 

 from the base of the sterile lamina, only 

 5-15 mm long; spike 5-10 mm long; 

 sporangia 10-15 pairs, apex short; spores 

 .05 mm Ig, reticulate, areolae 20-25, 

 rounded, striae unequal, not elevated." — 

 E. G. Britton. Torr cl b 24:555 (30D 

 1897). near SD. 



Other species credited to North Amer- 

 ica north of Mexico are the following: 

 O: ALASKANUM E. G. Britton. 

 O: ABENABIUM E. G. Britton. 

 O: ENGELMANNI Prantl. 



"Plants S-22 cm hi; rtstalk clindric 

 with long, brown rts, oft bearing 2-3 

 fr'ng and 1 sterile ]f on tbe ^ame plant 

 with the sheathing base of the old lvs 

 frequently persistent; petiole subter- 

 ranean or partly exserted, 4-10 cm, long; 

 sterile If elliptic or lanceolate-elliptic, 

 obtuse but sharply apiculate, 3-9 cm Ig, 

 1.5-5 cm broad; fleshy, becoming pellu- 

 cid when old and dry. slightly paler be- 

 neath; basal veins 13 or more, median 

 one slightly stronger and unbranched 

 below the middle of the frond, forking 

 and anastomosing with the lateral ones 

 above; lateral inner veins parallel and 

 approximate, outer ones arcuate-erect; 

 transverse veinlets oblique and large, 

 forming broad oblong-hexagonal areas 

 with num anastomosing or free veinlets 

 included; cells of the epidermis flexuous, 

 much elongated in the middle beneath, 

 stomata num; peduncle starting from 

 the petiole or the base of the sterile la- 

 mina. 3-9 cm long; spike 1.5-2.5 cm long, 

 apiculate, sporangia 12-27 pairs; spores 

 .045-. 05 mm in diam, areolae 15-20. an- 

 gular, striae not elevated." — E. G. Brit- 

 ton. Torr Cl b 24:554 (30D 1897). 



Considered by Underwood as O: vul- 

 gatum. 



Order MARSILIACEAE R. Br. 

 Genus MARSILIA Linnaeus. 



Sporocarps ovoid ; lvs quadifoliate. A 

 genus of 40 or more species. 

 *Sporocarps 2-6 on each peduncle. 

 M. QUADRIFOEIA L. 



Plant com slender, 5-12 cm hi; lfts 

 variable, 4-14 mm wide, 5-15 mm long, 

 margins entire, smooth, or rarely with 



2 (rarely 3) on a branching peduncle, 

 scattered hairs when young; sporocarps 

 wnicn is com attached to the stipe near 

 its base, but sometimes as much as 2 

 cm above; young sporocarp with short 

 y'ish-brown hairs, later becoming naked 

 and dark p; lower tooth obtuse, upper 

 small, acute or obtuse; sori 8-9 in each 

 valve. Bantam Lake, Litchfield Co. Conn 

 (Dr. T. P. Allen). La (Dr. Hale), fide 

 Wood. Cl-bk hot 810. 



M: MACROFODA Engelmann, Am J Sci, 

 sr 2, 3: 56 (1847). 



Plant robust, 10-25 cm hi; lfts large, 

 2-5 cm Ig, 2 cm wide or less, com undu- 

 late, clothed with w hairs on both sides 

 when young, becoming smoother with 

 age; sporocarps 2-6, on erect branching 

 peduncles, ascending, densely villous, 

 6-8 mm lg, 5-6 mm wide; raphe short, 

 lower tooth obtuse, upper inconspicuous 

 or 0; sori 10 in each valve. Tex; NM. 

 Synonym: M. macropus A. Br. (fide Un- 

 derwood). 



** Sporocarps 1 (rarely 2) on each pe- 

 duncle. 



M: UNCINATA A. Br. 



Plant 6-20 cm hi; lfts nearly smooth, 

 entire, 10-16 mm lg; sporocarps 6 mm 

 wide, 8 mm lg; peduncles 15-30 mm lg, 

 2-4 times as long as sporocarps; raphe 

 long, terminating in 2 approximate teeth, 

 upper longer and mostly uncinately cur- 

 ved; sori 13-14 in each valve. La (Hale) 

 Tex (Reverchon). 

 MARSILIA VESTITA H. & G. 



Plant 3-6 cm hi; lfts entire or slightly 

 toothed; sporocarps 4-7 mm long, 3-5 mm 

 wide; raphe short, lower tooth short and 

 blunt, upper acute, a little longer, some- 

 times curved; paleae varying from soft, 

 den e and spreading to short and ap- 

 pressed, in mucronata forms, where it is 

 sometimes 0; sori 6-11 in each valve; a 

 very variable specie-. Ark; Ar; Tex; 

 Kans; Nev; Ore; Wash; Mont; Dak; SD. 

 Svnonvm: M. mucronata A. Br. 

 M: TENUIFOIIA Engelmann. 



Plant somewhat slender, 5-15 cm hi; 

 lfts 2-4 mm wide, more or less falcate, 

 apex often somewhat truncate and un- 

 equally toothed, villous with appressed 

 hairs; sporocarps single, 5-8 mm long, 

 4-5 mm wide, teeth divergent, subequal; 

 sori 9-11 in each valve. Texas. Syn- 

 onvm: M. vestita tenuifolia. Underwood 

 & Cook. 



Genus PILULARIA Linnaeus. 



Sporocarps globose, lvs filiform. Six 

 species. 



PTLULARTA AMERICANA Al. Br. 



Lvs setiform, 1' long; sporocarps 1" 

 in diam. attached by the side to a short, 

 descending peduncle, com 3-celled; ma- 

 crospores 13-17 in each cell, not con- 

 stricted in middle. S Bar (Mrs. Cooper) 

 Ark (Nuttall); SD! 



S AIi VINT ACE AE . 

 SAX.VINIA Schreb. 



Lvs 6-9" long, with a distinct midrib. 

 Named for Salvini, a Florentine profes- 

 sor. Contains 13 species. 

 S: NATANS Hoffm. 



Lvs oblong, horizontal, rounded or 

 slightly cordate at base, %-l' long, 

 bright g above, the under surface mat- 

 ted with brown, pellucid hairs; sporo- 



