8 TAXACEAE. 



irregular ridges; microspores papillose to spinulose. Submersed in 1-3 feet 

 of water, Lake Coeur d'Alene, Idaho, and doubtless most of the lakes of the 

 region. 



Isoetes minima A. A. Eaton. Leaves 6-12, 2-4 cm. long, terete, slender; 

 sporangia not spotted; velum broad, covering most of the sporangium; 

 megaspores with a circle of long spines on the equator; microspores papillose 

 and with few spinules. Wet places near Waverly, Suksdorf. 



Isoetes howellii Engelm. Leaves 18-50, rather slender, 10-35 cm. long, 

 erect or nearly so, semi-lunate or helmet-shaped in cross section, striate, with 

 abundant stomata above; megasporangia dark-brown, the megaspores bright 

 white, rough, with low, more or less confluent tubercles; microsporangia 

 olivaceous, elliptic or oblong, much pitted, 6-8 mm. long, partly covered by 

 the narrow wings of the velum, the microspores unsymmetrical, spinulose on 

 the ridges. 



Borders of ponds near Moscow, Idaho. The species has been redescribed 

 as Isoetes underwoodii Henderson. 



Isoetes melanopoda J. Gay. Leaves 15-60, dark-colored at base, 10-45 

 cm. long, with four principal and numerous peripheral bast-bundles; velum 

 very narrow; sporangia spotted; microspores spinulose. Shallow ponds in 

 the Craig Mountains, Idaho, Heller. 



PHYLUM II. SPERM ATOPHYTA. Seed Plants. 



Highly organized plants, mostly producing flowers and 

 always producing seeds, each of which contains a young 

 plant (the embryo) usually composed of a stem-like struc- 

 ture (the caulicle or hypocotyl) , one or more rudimentary 

 leaves (the cotyledons) and a terminal bud (the plumule or 

 epicotyl) ; megasporangia (ovules) usually borne on the side 

 or face of an open or closed modified leaf (the carpel) ; micro- 

 sporangia {anther-sacs) on the end or side of a modified leaf 

 (the filament) and bearing numerous microspores {pollen 

 grains) . 



Class IV. GYMNOSPERMAE. 



Ovules {megasporangia) naked, not enclosed in an ovary, 

 usually on the face of an open scale but sometimes on the 

 axis, in which case the scale is rudimentary or wanting; 

 stigmas none; cotyledons mostly several in a whorl, 

 occasionally only two ; perianth none. 



Family 7. TAXACEAE. Yew Family. 

 Trees or shrubs with evergreen linear leaves; flowers dioecious, 

 the staminate of a few scaly bracts and a few naked stamens, the 

 ovule-bearing of an erect ovule which in fruit becomes a bony 

 seed surrounded by a fleshy disk. 



