Podostemum

Michaux

Fl. Bor.-Amer.2: 164, plate 44 [as Podostemon]. 1803

Common names: Threadfood riverweed orchid-of-the-waterfall
Etymology: Greek podos, foot, and stemon, stamen, alluding to stamens elevated on foot-stalk (andropodium)
Found in FNA Volume 6. Treatment on page 70.
Roots green, photosynthetic; haptera (fleshy disclike or fingerlike outgrowths) arising along flanks of roots serving as anchorage. Leaves with 1–2 basal sheaths; stipules extensions of boat-shaped leaf base; petiole round to elliptic; blade symmetric, ultimate divisions linear, awl-shaped, or spatulate, apex rounded, blunt, acute, or apiculate. Inflorescences apical or lateral, 1–12-flowered, pedicellate; spathella clavate, smooth or papillate, apex rounded or with nipple, rupturing apically into 1–6 irregular segments. Pedicels expanded at apex, elongating during anthesis. Flowers zygomorphic; tepals scalelike, 2 at base of ovary on either side of andropodium (lateral tepals), shorter than ovary, 1 (andropodial tepal) arising at top of andropodium from fork between 2 stamen filaments; anthers basifixed, quadrangular; thecae equal or inner longer than outer, apices rounded, distinct, dehiscence introrse; ovary oriented obliquely on pedicel, 2-locular, ellipsoidal; ovules 25–200; placentation axile; stigmas distinct, simple, bent toward anthers prior to spathella rupture, divergent and elongating during anthesis. Capsules 2-locular, persistent valve oriented obliquely on pedicel, each valve 3-ribbed, suture margins thickened, riblike. Seeds 0–42[–203].

Distribution

c, e North America, Mexico, West Indies (Dominican Republic), Central America, South America.

Discussion

Species 11 (1 in the flora).

Facts about "Podostemum"
AuthorC. Thomas Philbrick + and Garrett E. Crow +
Common nameThreadfood +, riverweed + and orchid-of-the-waterfall +
EtymologyGreek podos, foot, and stemon, stamen, alluding to stamens elevated on foot-stalk (andropodium) +
IllustratorJohn Myers +
Referencephilbrick1983a +, philbrick1984a +, philbrick1992a +, philbrick2004a + and rutishauser2003a +
Taxon namePodostemum +
Taxon parentPodostemaceae +
Taxon rankgenus +
VolumeVolume 6 +