BUR REED FAMILY
(Sparganiaceæ)
The Bur Reeds are marsh-inhabitating plants, some growing along the muddy shores of ponds or streams, while other species are strictly aquatic, growing in the water with floating leaves. Like the [Cat-tails] they are not in the least dependent upon insects for fertilization. The two kinds of flowers, staminate and pistillate, are always in separate spherical clusters usually alternately arranged along the stem.
(A) Great Bur Reed (Sparganium eurycarpum) is stout and erect, two to three feet in height. The mature heads, or fruit, about one inch across; composed of wedge-shaped nutlets arranged in the form of a sphere. The basal leaves are similar to those of the [Cat-tail] and clasp the stems. These plants are found in the whole of the U.S. and southern Canada, flowering from June to August.
(B) Branching Bur Reed (S. androcladum) throws off several weak flower-bearing branches from the angles of the upper leaves.
WATER PLANTAIN FAMILY
(Alismaceæ)
Genus Arrow-head (Sagittaria). Arrow-heads or Sagittarias are among our most beautiful water plants. The leaves vary greatly in shape but are always graceful in appearance. All species have three pure white petals with a golden centre formed by the large anthers. They usually grow in the water but sometimes on the muddy shores, and flower in June.
(A) Broad-leaved Arrow-head (Sagittaria latifolia) has broad, arrow-shaped leaves on long petioles from the root. The 3-petalled white flowers grow in whorls of three, the upper ones being staminate and the lower pistillate. Seed, winged on both edges and with a twisted horizontal beak. This species is smooth, but a variety (pubescens) has the stem quite wooly. Common in the whole of our range.
(B) Narrow-leaved Arrow-head (S. Engelmanniana) has very narrow leaves with linear sagittate bases. The seeds are winged but the beak points upward instead of being bent at an angle as in the last.