. An illustrated flora of the northern United States, Canada and the British possessions : from Newfoundland to the parallel of the southern boundary of Virginia and from the Atlantic Ocean westward to the 102nd meridian. Botany. RIVKR-WEED lAMILV. Family 43. PODOSTEMACEAE Lindl. Xat. Syst. Ed. 2, 190. RivER-WEEO Family. 1836. Small aquatic fresh-water mostly annual fleshy herbs, the leaves usually poorly differentiated from the stem, the whole structure commonly resembling the thallus of an alga or hepatic, the small usually perfect flowers devoid of any perianth and subtended by a spathe-lik
. An illustrated flora of the northern United States, Canada and the British possessions : from Newfoundland to the parallel of the southern boundary of Virginia and from the Atlantic Ocean westward to the 102nd meridian. Botany. RIVKR-WEED lAMILV. Family 43. PODOSTEMACEAE Lindl. Xat. Syst. Ed. 2, 190. RivER-WEEO Family. 1836. Small aquatic fresh-water mostly annual fleshy herbs, the leaves usually poorly differentiated from the stem, the whole structure commonly resembling the thallus of an alga or hepatic, the small usually perfect flowers devoid of any perianth and subtended by a spathe-like involucre, or in some genera with a 3-5-clcft mem- branous calyx. Stamens hypogynous, only 2 in the following genus, numerous in some others; filaments united or distinct; anthers 2-cclled, the sacs longitudinally dehiscent. Ovary stalked or sessile, 2-3-celled; ovules usually numerous in each cell, anatropous; styles 2 or 3, short. Capsules 2-3-celled, ribbed. Seeds numer- ous, minute, without endosperm; embryo straight. About z\ gen species, mostly in the tropics, only the following North American. I. PODOSTEMUM Michx. Fl Bor, Am. 2: 164. pi. 44. 1803. Habit of the several species various. Flowers sessile or very nearly so in the spathe-like involucre. Perianth none. Stamens 2, their filaments united to near the summit; anthers 2, oblong or oval. Staminodia 2, filiform. Ovary ovoid, 2-celled; stigmas 2, nearly erect, short, subulate. Capsule ovoid, 6-io-ribbed, 2-valved. [Greek, stalked-stamens.] About 12 species of rather wide geographic distribution, the following typical. Besides the following, another occurs in the southern United States. Podostemum ceratophyllum Michx. River- weed. Thread-foot. Fig. 2130. Podoslen 1803. ophyllum Michx. Fl. Bor. An Plant dark green, rather stiff, firmly attached to stones in running water, densely tufted, I'-io' long, the leaves narrowly linear, sheathing at the base, commonly split above into almost filiform segments or lobes. Flowers
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1913
