carps 4-8 in a cluster. Bois Brule Bot- 

 toms, Perry Co, Mo (Demetrio). NY 

 (Pursh). Synonym: Marsilia natans L. 

 AZOX.X.A Lam. Al:380d. 



Lvs minute, num, closely imbricate, 

 deeply lobed. Small moss-like plants, 

 with pinnately branched sts. Five 

 species. 



A: CABOLINIAXA Willd, sp pi 5:541. 

 B 2:352 Da 20. 7* 1:100. A l:380d. 



Plant 4-12" broad, much branched; Ivs 

 with ovate lobes, the lower reddish, the 

 upper g with a r'ish border; macrospores 

 with a minutely granulate surface; 

 masses of microspores barbed at tip. 

 Synonyms: A. microphylla Kaulf. A 

 Alexicana Schlecht. 



A: rXUCUXiOXDES Lam. A l:38d. 7* 

 1:101. 



"La Honda, San Mateo Co. Cal, 1890 

 (Brandegee), the plants so crowded as 

 to stand upright. A larger and coarser 

 plant than A Caroliniana, easily dis- 

 tinguished in fr by the non-septate ap- 

 pendages to the massulae. Baker (Hand- 

 book of Fern Allies 137), gives its habi- 

 tat as 'South America, mainly on the 

 west side.' This adds another Chilian 

 plant to the Cal flora." Underwood, Zoe 

 1:101. 

 A: lOXOMEYSIS Greene. 



Description not seen by the writer. 



Order EQUI8ETACXAE DC. 

 XQUIilTUM L. 



Horse-tail or scouring-rush, the only 

 genus known in this order. 

 Section KUEQUIIXTUK. Sts ann, stom- 

 ata scattered. 



*Sts of 2 kinds, the pale or brownish 

 fertile sts appearing earlier than the 

 herbaceons sterile ones; fr'ng in spring. 



I. Fertile sts simple, soon withering. 

 E:ABYEXSE L. 



Horsetail sterile sts g, rather slender, 

 1-2 hi, 6-19-furrowed; branches num, 

 long, mostly simple, 4-angled, minutely 

 roughened, lowest joint com longer than 

 sheath of st; fertile sts 4-10' hi, light 

 brown, the loose scarious sheath mostly 

 distant, w'ish, ending in about 12 brown 

 acuminate teeth; spike rarely over 1' 

 long. Va to Cal; Greenland. Synonym: 

 E. boreale Bong. 

 E: TEZ.MATEZA Ehrh. B 2.330. 



Sterile sts ivory w or g'ish, stout, 2-6 

 hi, 20-40-furrowed; branches very num, 

 erect-spreading, simple, 4-5-angled, the 

 ridges rough and sulcate, lowest joint 

 shorter than sheath of st; fertile sts 

 10-15' hi, w, many-furrowed, the loose 

 brownish sheaths elongate, deeply 20-30- 

 toothed. Cal; Ore; north. Synonyms: 

 E. fluviatile Sm. E. eburneum Schreb. 

 E. maximum Und. not Lam. 



II. Fertile sts when older producing 

 herbaceous branches, only the naked 

 apex withering. 

 E: FBATENSE Ehrh. 



Sterile and finally fertile sts produc- 

 ing straight, simple branches; sheaths of 

 st with about 11 short, ovate-lanceolate 

 teeth, those of branches 3-toothed. Mich; 

 Wis; north. Synonyms: E. umbrosum 

 Willd. E. triquetrum Bory. E. Drum- 

 mondii Hooker. 

 E: SILVATICUM L. 



Sterile and fertile sts com 12-furrowed, 



producing compound branches, branch- 

 lets curved downward; sheaths loose, 

 those of st with 8-14 bluntish teeth, 

 those of branches with 4-5, of branch- 

 lets with 3 divergent teeth. Va; Mich; 

 Labrador. 



**Sts of 1 kind, herbaceous; branches 

 simple or o; fr'ng- in summer. 



I. Sheaths somewhat loose. 

 E: PALUSTRE L. 



Sts slender, 10-18' hi. very deeply 5-9- 

 grooved. the grooves separated by nar- 

 row, wing-like ridges, roughish; sheaths 

 with about 8 loose-awl-shaped, whitish 

 margined teeth; branches few in a whorl, 

 with mostly 5-toothed sheaths. NY; 

 Wis; BC; north. Synonym: E. pratense 

 Reicheub. 

 E: X.XTOBAXJB Kuhl. 



Sts slightly roughened, 6-19-grooved, 

 the carinae convex; sheaths sensibly 

 dilated above, the uppermost bell-shaped; 

 Ivs convex, angled beneath, separate at 

 the commisural groove; teeth herbaceous, 

 membranous at margin, narrow, lanceo- 

 late; branches of 2 kinds, the 4-angled 

 hollow, the 3-angled solid, first joint a 

 little longer or shorter than sheath of 

 st; spores abortive, elaters com o. Bay 

 of Quinte, Canada (Macoun); Vt 

 (Pringle); Oswego river, NY (Wibbe). 



II. Sheaths appressed. 

 X: rLUVIATILE L. 



Sts 2-3 hi, slightly to many-furrowed, 

 smooth, com producing upright branches 

 after fructification; sheaths appressed, 

 with about 18 dark brown, short, acute, 

 rigid teeth; air-cavities o under the 

 grooves, small under the ridges. Va to 

 Wash; north. Synonyms: E. limosum L. 

 E. uliginosum Muhl. E. heleocharis 

 Ehrh. 



Section KZPFOCHAETE. Sts per, ever-g; 

 spikes tipped with a rigid point; stomata 

 in regular rows; fr'ng in summer. 

 -Sts tall and stout, com many-grooved. 



I. Branches num, regularly whorled. 

 Z: BAMOSISSXMT7M Desf. 



Sts grooved, more or less roughened, 

 6-26-furrowed; sheaths dilated, toothed; 

 teeth not grooved, persistent or decid, 

 leaving only a triangular, very rarely a 

 truncated margin; Ivs more or less dis- 

 tinct, 3-4-carinate; branches, when pres- 

 ent, 4-9-angled; series of stomata in 1-4 

 lines; inner bark of ridges higher than 

 grooves; ridges convex, marked with 

 bands, never with 2-rowed tubercles. 

 Cuba; Mexico; B C. 



II. Branches few and irregular or 

 wholly 0. 

 E: BOBUSTAM A. Braun. B 2:330. 



Sts 3-11 hi, sometimes nearly 1' 

 thick, 20-48-furrowed; ridges roughened 

 with a single series of transversely ob- 

 long, siliceous tubercles; sheath short, 

 cylindric, marked with black girdles at 

 base, and at base of caducous teeth; 

 ridges of sheaths tricarinate. O; La; 

 Cal; north. 

 E: HIEMALE L. 



Scouring-rush. Sts 1-4 hi, rough, 

 8-34-furrowed; ridges with 2 indistinct 

 lines of tubercles; sheaths rather long, 

 cylindric, marked with 1 or 2 black 

 girdles; ridges of sheath obscurely quad- 

 ricarinate; teeth membranous soon decid. 



