92 ALISMACEAE. 
13. Sagittaria platyphylla (Engelm.) J. G. Smith. Ovate-leaved Sagittaria. 
(Fig. 205.) 
Sagitlaria graminea var, platyphylla Engelm. in A. 
Gray, Man. Ed. 5, 494. 1867. 
Sagitlaria platyphylla J. G. Smith, Ann. Rep. Mo. 
Bot. Gard. 6:55. pl. 26. 1894. 
Monoecious, glabrous, scape erect, simple, rather 
weak, mostly shorter than the leaves. Leaves 
rigid, the blades ovate, ovate-lanceolate or ovate- 
elliptic, short-acuminate or acute at the apex, 
rounded, gradually narrowed or rarely cordate or 
hastate at the base, seemingly pinnately veined, 
2’-6’ long; bracts broadly oyate, acute, connate at 
the base, 2’’-4’’ long; flowers 8’’-14’” broad ; fer- 
tile pedicels stout, divergent in flower, reflexed in 
fruit, 14’-2'4’ long; filaments dilated, pubescent, 
rather longer than the anthers; achene obliquely 
obovate, winged on both margins, the dorsal mar- 
gin somewhat crested, the sides with a sharp wing- 
like ridge. : 
In swamps and shallow water, southern Missouri to 
Mississippi and Texas. Phyllodia, when present, 
oblong or oblanceolate. July-Sept. 
14. Sagittaria subulata (L.) Buchenau. Subulate Sagittaria. (Fig. 206. ) 
Alisma subulata I,. Sp. Pl. 343. 1753. 
Sagitlaria pusilla Nutt. Gen. 2: 213. 1818. 
Sagitlaria subulata Buchenau, Abh. Nat. Ver. Bremen, 
2:490. 1871. 
Monoecious or rarely dioecious, scape very slen- 
der, 2’-6’ high, few-flowered, about equalling the 
leaves. Leaves all reduced to rigid phyllodia or 
sometimes bearing linear or linear-lanceolate 
blades, 1/-114’ long; bracts united to the apex or 
becoming partly separated ; flowers 5/’—-8’’ broad ; 
fertile pedicels reflexed and much longer than the 
bracts in fruit; stamens about 8; filaments about 
equalling the anthers, dilated, glabrous; achenes 
rather less than 1’’ long, obovate, narrowly winged, 
with 2 or 3 crests on each side, the wings and crests 
sometimes crenate; beak short. 
In tide-water mud, southern New York and Penn- 
sylvania to Florida and Alabama. July-Sept. 
Sagittaria subulata gracillima (S. Wats.) J. G. Smith, Mem. Torr. Club, 5: 26. 1894. 
Sagittaria natans var. (?) gracillima S. Wats. in A. Gray, Man. Ed. 6, 556. 1890. 
Submerged ; leaves 2°-4° long, bladeless or bearing small 3-nerved lanceolate blades, 1'-2° 
long, 3'’-4'’ wide ; scape simple, terete or compressed, about as long as the leaves ; flowers few, 8'’— 
10’ broad. Eastern Massachusetts and Rhode Island. Perhaps a distinct species. Fruit not seen. 
x 
Family 6. VALLISNERIACEAE Dumort. Anal. Fam. 54. 1829. 
TAPE-GRASS FAMILY. 
Submerged or floating aquatic herbs, the leaves various. Flowers regular, 
mostly dioecious, appearing from an involucre or spathe of 1-3 bracts or leaves. 
Perianth 3—6-parted, the segments either all petaloid or the 3 outer ones small 
and herbaceous, the tube adherent to the ovary at its base in the pistillate 
flowers. Stamens 3-12, distinct or monadelphous. Anthers 2-celled. Ovary 
1-celled with 3 parietal placentae or 6-9-celled. Styles 3-9, with entire or 
2-cleft stigmas. Ovules anatropous or orthotropous. Fruit ripening under 
water, indehiscent. Seeds numerous, without endosperm. 
About 14 genera and 40 species of wide distribution in warm and temperate regions. Besides 
the following, another genus, Halophila, occurs on the coast of Florida. 
Stem branched ; leaves whorled or-Opposite. 1. Philotria. 
Acaulescent ; stoloniferous ; leaves grass-like, elongated. 2. Vallisneria. 
Stem stoloniferous ; leaves broad, rounded, cordate, petioled. 3. Limnobium. 
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