1054 ISOETACEAE 



3. I. Bolanderi Engelm. Leaves erect, soft, bright green, tapering to a fine 



point, 5-10 cm. long, thin-walled; stomata few; ligtile triangular; velum narrow; 



sporangia unspotted; macrospores 0.3-0.45 mm. thick; microspores deep brown 



spmulose. In water and mud: Wash.— Wyo.--Colo.— Calif. Plain— Mont 

 Au-S. 



1. ^A I- Howellii Engelm. Leaves 5-20 cm. long; stomata numerous; bast- 

 bundles 4; velum narrow, densely spotted; ligule short triangular to 4 mm. long: 

 macrospores 0.48 mm., with low blunt crests; microspores light brown, with low 

 tubercles or spines. /. nuda Engehn. /. Underwoodii Renders Borders of 

 ponds : B.C.— Mont.— Ida,— Calif . Plain— Submont. Je-Au. 



6. I. Nuttallii A. Br. Trunk almost globose, 3-lobed; leaves slender, bright 

 green, 7-20 cm. long; stomata many; bast-bundles 3; velum broad, covering the 

 sporangia; macrospores 0.25-0.5 mm.; microspores brown, papillose. / ovaca 

 Nutt. /. Suksdorfii Baker. Mud: B.C.— Ida.— Calif. Son,— Plain. Mr-Jl 



Family 7. LYCOPODIACEAE. Club-moss Family. 



Low, erect or trailing plants, somewhat resembling mosses, wuth leafy, 

 usually branched, often elongate stems. Leaves small, lanceolate or subu- 

 late or sometimes oblong or roundish, some bearing on their axils or on their 

 upper surfaces solitary 1-3-celled sporanges. Spores minute, of one kind. 



1. LYCOPODIUM L. Cltjb-moss, Ground Pine. 



Perennial plants, with evergreen, usually stiff, commonly imbricate, one- 

 nerved, 4r-16-ranked leaves. Main stems usually creeping, with aerial branches. 

 Sporangia flattened, coriaceous, usually reniform, 1-celled, opening by a transverse 

 slit aroimd the margin, borne in the axils of ordinary or modified and bract-hke 

 leaves. Spores sulphur-colored. 



Leaves hoUow at base, aU or mostly aU ascending, of nearly one length. "- ^ • - 



Leaves flattened, not hollow at base, spreading or deflexed, longer and 'shorter In 

 alternating zones. 2 L voronhilum 



Sporanges borne in the axils of bracts arranged in spikes on the aerial branches 



Spikes sassile, or with st^,lks not more than 1 cm. long 



Aerial branches all simple. 3 r inu-n^ntum 



Aerial branches, at least in part, branched tnunaamm. 



Leaves of the ultimate divisions of the aerial branches in 4 rows. 



Leaves of the ultimate divisions of the aerial branches ui more than^4^rows 

 Aerial branches tree-like. 5 £ obscurum 



Aerial |>^[anches not tree-like, mostly loosely forking or* forming compact 



Leaves of the ultimate divisions of the aerial branches in 5 rows. 



Leaves of the ultimate divisions of the aerial branches in 8 rows. ' 



Spikes borne on bracteate peduncles more than 2 cm. long '^' ^' ^^^^^^^^^* 



Leaves of the divisions of the aerial branches in 4 rows. 8 L romnlnnnt^im 



Leaves of the di\asions of the aerial branches m many rows. 9." l\ clavatum 



1. L. Selago L. Main stems very short, dichotomously branching into 

 upcurved or erect forking branches forming a tuft 2.5-24 cm. high; leaves crowded 

 appressed or ascending or rarely a few reflexed, triangular to Hnear-acuminate 

 or aciculate, acute, entire; sporophylls shorter than the leaves, triangular" pla^^ 

 often bearing gemmae. Rocks: Greenl. — Ne^\i. — Me. — N.Y. — Ont — Alaska 

 Mont.— Wash.— Va.—N.C—Tenn.; Mex.; Eu. 



2. L. porophilum Lloyd & Underw. Main stems short, upcurved, dichoto- 

 mously branching into upcurved or erect forking branches forming a tuft 3-35 

 cm. high; leaves crowded, spreading or reflexed, hnear or nearly so, entire or 

 rarely very minutely denticulate, those in the zones of the longer sUghtly broad- 

 ened above the middle and similarly contracted toward the base, those in the 

 zones of the shorter broadest at the base, but very gradually tapering; sporo- 

 phylls entire or mmutely denticulate above the middle, acuminate; plant often 



