2. Lens palustris sive aquatica quadrifolia. 
Crosse-leafed Water Lentils or Duckes meate. 
This other Lens hath a small long slender roote shoot- 
ing forth square slender weake and trailing stalkes, with 
sundry small leaves upon severail long foot stalkes, stand- 
ing together at the joynts distinét one from an other, 
which are parted into four leaves a peece and sometimes 
it has beene observed with six leaves, each end being 
round and lying in a square forme like a crosse upon the 
water: at the joynts likewise with the leaves, come forth 
diverse small heads of seede like unto the fielde Lentils, 
but not so flat, being thicke and hard. Lugdunensis 
setteth forth this kind of water plant, by the name of 
Lemma Theopkhrastz, in a much different manner.” 
25. ISOETES L. 1751. 
The name ts derived from éros, annus, isos, semtlis 
according to Linneus (Phil. Bot. ] who also states 
[Iter. scan.] that the name ts old and was formerly 
applied to Sedum. [Plini Hist. } 
Mostly small, aquatic, amphibious or terrestrial plants. 
Stem a fleshy, depressed corm. Leaves awl-shaped or 
linear, dilated atthe base. Sporangia orbicular or ovoid 
sessile in the axils of the leaves. Spores of two kinds. 
{ Leaves 5-13 cm. long. 
1. I. saccharata Engelm. esd: 
Isoetes saccharata E-ngelm, 1867. in Gray, Man. 
676, ed. 6. 699. Underw. in Ill. Fl. 1: 47; Nat. 
Ferns 145 ; in Britt. Man. 28. Clute, Fern Allies 
240. 
53 
