38 GBAMINEAE (GRASS FAMILY) 



3. Sagittaria longiloba Engelm. in Torr. Bot. Mex. Bound/^212. 1859. 

 Glabrous: petioles and scapes rather long and slender': loaves with short 

 lanceolate blade and usually very long linear-lanceolate acute lobes, 2-3 times 

 as long as the blade: bracts lanceolate, acuminate: stamens numerous; the 

 filaments longer than the anthers: achene quadrate-obovate, winged all 

 around, beak wanting or nearly so. — Nebraska and Colorado to Mexico. ' 



4., Sagittaria latifoUaWilld. Sp. PL 4: 409. 1806. Monoecious, as are all of 

 ours, glabrous or nearly so, ^10 dm. high: leaves broad and abruptly con- 

 tracted to the acute apex; basal lobes usually broad, divergent and often 

 shghtly out-curved, about half as long as the blade: bracts acute or obtuse: 

 flowers rather large, 2-3 cm. broad: achene with broad. wing on eitherside 

 narrowed into the nearly horizontal slender beak, one third as long as the 

 body. — Very variable; throughout Ilorth America; infrequent in our range. 



15. HYDROCHARITACEAE Aschers. Tape GRAsa Fainjhly 



Represented in our range by a single genus, which see for character^. ' , , 



PHILOTRIA naf. Watebweed ^ ,;,,,.,., 



Perennial slender submerged herbs, with elongated branching stems 

 thickly beset with pellucid and veinless, l-herved,'sessilte, whorled or opposite 

 leaves. The staminate flowers (rarely seen) commonly break off, as in Vallis- 

 neria, and float on the surface, where they expand and shed their pollen 

 around the stigmas of the fertile flowers, raised to the surface by the pro- 

 longed calyx-tube. — {Elodea Michx.) 



1. Philotria canadensis (Michx.) Brit: Science II. 2r5. 1895. Leaves in 

 threes or fours, or the lower opposite, varying, from ihnea,r to oval-obloiig,,, mi- 

 nutely serrulate : stamens 9 in the sterile flowers, 3-6 almost sessile anthers in 

 the fertile, [f. angustifolia (Muhl.) Brit, and P. mino'f] (Engelm.) Small.] 

 — Slow streams and ponds, common; widely distributed ia North America; 

 rather rare in our range. , 



16.' GRAMINEAE Juss. jGrass Family ;;' „ 



Annual or perennial herbs of various habit, rarely shrubs or trees. Stems 

 (3ulms) generally hollow or sometimes solid, the nodes closed. Leaves shbath- ' 

 ing, the sheaths usually split to the base on the side opposite the blade, a 

 scarious or cartilaginous ring (ligule), borne at the base of the leaf -blade. 

 Inflorescence spicate, racemose, or paniculate, consisting of spikelets com- 

 posed of two-many 2-ranked imbricated bracts, the 2 lo\sfest in ,1;lfp complete 

 spitolet always empty (glumes), 1 or both sometimes wanting. One or more 

 of the upper bracts (lemmas) usually contains in the axil a flower, which ia 

 ■usually inclosed by a bract-like awnless organ called the palet, placed opposite 

 the lemma with its back to the axis (rachilla) of the spikelet, generally,. 

 2-keeled. Flowers perfect or staminate, sometimes monoecious or dioecious^ 1 

 subtended by 1-3, usually 2 minute hyaline scales (lodicules) placed at the 

 base of the ovary opposite the, palet. Stamens 1-6, usually 3; anthers 2-celled, 

 versatile, Ipngitudiiially dehiscent. Ovary 1-celled, 1-pyuIed; styles 1-3, 

 usually 2 and lateral;, stigmas hairy or plumose.- Fruit a seed-Hke grains 

 (caryopsis). Endosperm starchy. 



Various terms have been used to desi^ate the bracts (glumes) of the \ 

 spikelets. In the treatment here Mr. C V. Piper's suggestion has been adopted, '■ 



