15 



16 



carps 4-8 in a cluster. Bois Brule Bot- producing compound oranches, branch- 

 toms, Perry Co, Mo (Demetrio). NY lets curved downward; sheaths loose,. 

 (Pursh). Synonym: Marsilia natans L. those of st with 8-14 bluntish teeth,. 

 AZOLLA Lam. Al:3S0d. those of branches with 4-5, of branch- 



Lvs minute, num, closely imbricate, lets with 3 divergent teeth. Va; Mich; 

 deeply lobed. Small moss-like plants, Labrador. 



with pinnately branched sts. Five **Sts of 1 kind, herbaceous; branches 

 species. simple or o; fr'ng in summer. 



A: CAROLINIANA Willd, sp pi 5:541. I. — Sheaths somewhat loose. 

 B 2:352 Da 20. Z 1:100. A l:380d. E: PALUSTRE L. 



Plant 4-12" broad, much branched; lvs Sts slender, 10-18' hi. very deeply 5-9- 

 with ovate lobes, the lower reddish, the grooved, the grooves separated by nar~ 

 upper g with a r'ish border; macrospores row, wing-like ridges, roughish; sheaths 

 with a minutely granulate surface; with about 8 loose-awl-shaped, whitish 

 masses of microspores barbed at tip. margined teeth; branches few in a whorl, 

 Synonyms: A. microphylla Kaulf. — A with mostly 5-toothed sheaths. NY; 

 Mexicana Schlecht. Wis; BC; north. Synonym: E. pratense 



A: FII.ICUI.GIDES Lam. A l:38d. Z Reicheub. 

 1:101. E: XiITORALE Kuhl. 



"La Honda, San Mateo Co. Cal, 1890 Sts slightly roughened, 6-19-grooyed, 

 (Brandegee), the plants so crowded as the carinae convex; sheaths sensibly 

 to stand upright. A larger and coarser dilated above, the uppermost bell-shaped; 

 plant than A Caroliniana, easily dis- lvs convex, angled beneath, separate at 

 tinguished in fr by the non-septate ap- the commisural groove; teeth herbaceous, 

 pendages to the massulae. Baker (Hand- membranous at margin, narrow, lanceo- 

 book of Fern Allies 137), gives its habi- late; branches of 2 kinds, the 4-anglei 

 tat as 'South America, mainly on the hollow, the 3-angled solid, first joint si 

 west side.' This adds another Chilian little longer or shorter than sheath cf 

 plant to the Cal flora." — Underwood, Zoe st; spores abortive, elaters com o. Rv 

 1:101. of Quinte, Canada (Macoun s - Vt 



A: SOITOMENSIS Greene. (Pringle) ; Oswego river, NY (Wibbe . 



Description not seen by the writer. H. — Sheaths appressed. 



Order EQUISETACEAE DC. E: rLUVIATlLB L. 



EQUISETUM L. Sts 2-3° hi, slightly to many-furrowed. 



Horse-tail or scouring-rush, the only smooth, com producing upright branches 

 genus known in this order. after fructification; sheaths appressed, 



Section EUEQUISETUM. Sts ann, stom- with about 18 dark brown, short, acute, 

 ata scattered. rigid teeth; air-cavities o under the 



*Sts of 2 kinds, the pale or brownish grooves, small under the ridges. Va to 

 fertile sts appearing earlier than the Wash; north. Synonyms: E. limosum L. 

 herbaceons sterile ones; fr'ng in spring. — E. uliginosum Muhl. — E. heleocharis 



I. — Fertile sts simple, soon withering. Ehrh. 



E:ARVENSE L. Section HIPFOCHAETE. Sts per, ever-g; 



Horsetail sterile sts g, rather slender, spikes tipped with a rigid point; stomata 

 1-2° hi, 6-19-furrowed; branches num, in regular rows; fr'ng in summer, 

 long, mostly simple, 4-angled, minutely -Sts tall and stout, com many-grooved, 

 roughened, lowest joint com longer than I. — Branches num, regularly whorled. 



heath of st; fertile sts 4-10' hi, light E: RAMOSISSKVEXTM Desf. 

 brown, the loose scarious sheath mostly sts grooved, more or less roughened, 

 distant, w'ish, ending in about 12 brown 6-26-furrowed ; sheaths dilated, toothed; 

 acuminate teeth; spike rarely over 1* teeth not grooved, persistent or decid, 

 ' >ng. Va to Cal; Greenland. Synonym: leaving only a triangular, very rarely a 

 E. boreale Bong. truncated margin; lvs more or less dis- 



LJ: TELMATEIA Ehrh. B 2.330. tinct, 3-4-carinate ; branches, when pres- 



Sterile sts ivory w or g'ish, stout, 2-6° ent, 4-9-angled; series of stomata in 1-4 

 hi, 20-40-furrowed ; branches very num, lines; inner bark of ridges higher than 

 erect-spreading, simple, 4-5-angled, the grooves; ridges convex, marked with 

 ridges rough and sulcate, lowest joint bands, never with 2-rowed tubercles, 

 shorter than sheath of st; fertile sts Cuba; Mexico; B C. 



10-15' hi, w, many-furrowed, the loose II. — Branches few and irregular or 

 i^rownish sheaths elongate, deeply 20-30- wholly 0. 



toothed. Cal; Ore; north. Synonyms: E: ROBUST AM A. Braun. B 2:330. 



E. fmviatile Sm. — E. eburneum Schreb. — Sts 3-11° hi, sometimes nearly l r 



S. maximum Und. not Lam. thick, 20-48-furrowed ; ridges roughened 



II. — Fertile sts when older producing with a single series of transversely — ob- 

 herbaceous branches, only the naked long, siliceous tubercles; sheath short, 

 apex withering. cylindric, marked with black girdles at 

 3: PRATENSE Ehrh.. base, and at base of caducous teeth; 



Sterile and finally fertile sts produc- ridges of sheaths tricarinate. O; La; 

 ing straight, simple branches; sheaths of Cal; north, 

 st with about- 11 short, ovate-lanceolate E: HIEMALE L. 



teeth, those of branches 3-toothed. Mich; Scouring-rush. Sts 1-4° hi, rough, 

 Wis; north. Synonyms: E. umbrosum 8-34-furrowed; ridges with 2 indistinct 

 Willd. — E. triquetrum Bory. — E. Drum- lines of tubercles; sheaths rather long, 

 mondii Hooker. cylindric, marked with 1 or 2 black 



E: SILVATICITM L. girdles; ridges of sheath obscurely quad- 



Sterile and fertile sts com 12-furrowed, ricarinate; teeth membranous soon decid. 



