MARE S-TAIL FAMILV- 



iSl 



herbs, with 



2. MYRiorHVLLUM. — Leaves mostly wHoiied, pinnate ; sepals 

 4, superior : petals 4, ox absent ; staiiieits 2, 4, or 8, often in separ- 

 ate flowers from the carpels, but on the same plant (mon:tcious) ; 

 ea/pe/s 4, 



3. Callitk/chk. — Ztwv.f opposite, entire; sepa/s ■d.nd pe/a/s 

 absent ; sfaiiieii i ; earpe/s 4 (montecious). 



1. Hifpi'-Ris (Mare's-tail). — Glabrous, aquatic 

 erect, unbranched, leafy s/e//is : whorled, 

 narrow, entire /caz'w .• minute, axillary, solitary 

 Jloicers : ealy.x forming a minute, indistinctly 

 2-lobed rim to the ovary ; pefaLs al)sent ; 

 stainei! i ; caipel i, i-seeded ; fruit nut-like, 

 indehiscent. (Name from the Greek hippas, 

 a horse, oiira, a tail.) 



1. // ''u/x'dris (("ommon IMare's-tail): — 

 The only British species, a singular plant, with 

 erect, unbranched, jointed stetiis, tapering to 

 a point, bearing whorls of 6 — 10 narrow kafes 

 with hard tips, and incoiispicuous floivers 

 sessile in the axils of the upper leaves, and 

 often without stamens. — Not uncommon in 

 stagnant water. Not to be confounded with 

 the genus EqiiiselKin (Horse-tail), a plant 

 allied to the Ferns, Avhich also has a jointed 

 stem and whorled, rigid leaves, but bears its 

 fructification in terminal cones. — Fl. June, 

 July. Perennial. 



2. MvRioPHvi.LUM (Water Milfoil).- - 

 Glabrous, submerged plants ; leaves mostly 

 whorled and pinnately divided into numerous 

 hair-like segments ; flowers small, solitary or 

 in spikes, the lower often apetalous and pistil- 

 hte, intermediate ones perfect, and the upper 

 staminate, so that the inflorescence is poly- 

 gamous ; sepals 4, rarely 2, united, superiof ; 

 petals 4, 2, or absent : stamens generally 8, 

 rarely 2 or 4 ; carpels 4, witli feathery styles ; fruit dividing into 

 4, nut-like, indehiscent, one-seeded cocci. (Name from the Greek 

 murlos, countless, phulloii, a leaf, from its nitich-divided leaves. ) 



I. J/, veriullldtum (AMiorled 'Water Milfoil). — Rhizome creep- 

 mg ; stems floating, leafy; ^^ith short internodes ; leaves with 

 distant hair-like segments, collapsing when removed from the 

 water ; floicers \\\\\\.t, ui whorls of about : 5 each, forming an 



HIPPL'RIS ^"L"I.GAEIS 

 {Coitijuon J/arc'sUait). 



