Eriocaulon decangulare
Eriocaulon aquaticum
ten-angle pipewort
eriocaulon aquatique, seven-angle pipewort
linear or linear-attenuate, abruptly, then gradually, narrowing, 10–40(–50) cm, apex acute or obtuse.
linear-attenuate, 1–10 cm (–40 cm when submersed), apex often subulate.
scape sheaths shorter than principal leaves;
scapes linear, distally 1–2(–3) mm wide, multiribbed;
heads dull white, hemispheric to nearly globose, 7–15 mm wide, hard, very slightly flattened when pressed;
receptacle copiously hairy;
involucral bracts reflexed, obscured by reflexed proximal bracteoles and flowers, straw-colored, narrowly ovate to lanceolate, 2–4 mm, margins erose to entire, apex acute, glabrous or apex with white, club-shaped hairs;
inner bracts and receptacular bracteoles pale, linear to oblong or lanceolate, 3–4 mm, margins entire, sometimes becoming erose, apex narrowly acuminate, glabrous or apex with white, club-shaped hairs.
scape sheaths longer (shores) or shorter (submersed) than principal leaves, inflated;
scapes linear to filiform, 1 mm wide, (4–)5–7-ribbed;
mature heads white to pale gray, young heads dark, hemispheric to globose, 4–10 mm wide, soft, flattened when pressed;
receptacle glabrous or rarely with a few clear hairs;
involucral bracts becoming reflexed, obscured by proximal bracts and flowers, dark gray, broadly oblong to narrowly ovate or broadly obovate, 1–1.5 mm, margins entire, apex rounded, abaxially with white, club-shaped hairs, otherwise glabrous;
inner and receptacular bracts gray to near black, oblanceolate or cuneate, 1.5 mm, margins entire, apex acute, distal margins and abaxial apical surface with white, club-shaped hairs.
sepals 2, yellow-white, linear, curved, 3 mm, distal surface abaxially, adaxially with white, club-shaped hairs;
androphore club-shaped;
petals 2, yellow-white, translucent, triangular to linear, nearly equal, with small tuft of white, club-shaped hairs abaxially at apex;
stamens 4;
anthers black.
sepals 2, grayish, oblong-linear or linear-oblanceolate, curved, 1.5 mm, apex acute to rounded, margins and abaxial surface with white, club-shaped hairs;
androphore club-shaped;
petals 2, triangular, nearly equal, 0.5 mm, ciliate, hairs white, club-shaped;
stamens 4;
anthers black.
sepals 2, yellow-white, linear, 2–3 mm, apex acute, abaxially with white, club-shaped hairs at apex;
petals 2, pale, spatulate or narrowly elliptic, 1–2 mm, abaxially with translucent hairs proximally, white, club-shaped hairs distally, or adaxially glabrescent;
pistil 2-carpellate.
sepals 2, gray, oblong to narrowly obovate, curved, keeled, 1.5 mm, blade usually ciliate, distal abaxial surfaces with white hairs;
petals 2, pale, oblong-linear to linear oblanceolate, 1.5 mm, apex acute to obtuse, apically ciliate, adaxially with white, club-shaped hairs;
pistil 2-carpellate.
pale brown, ellipsoid, 0.75–1 mm, very finely cancellate or sometimes with cancellae concealed by rows of delicate nearly appressed hairs.
light brown or red-brown, ovoid to broadly ellipsoid, 0.5 mm, very faintly reticulate, not papillate.
Eriocaulon decangulare
Eriocaulon aquaticum
A possible variety, Eriocaulon decangulare var. latifolium Chapman ex Moldenke [in N. L. Britton et al., N. Amer. Fl. 19(1): 21. 1937], has yet to be thoroughly investigated. This plant typically is in the taller range and has thicker stems and scapes than in the type; it has very stiff blunt leaves to 50 cm × 13–20 mm with thicker scapes, heads 13–20 mm wide, and floral parts in the high range for the species. It occurs in wetter situations than usual for the species, and (fide R. R. Haynes, pers. comm.) flowers later. This morphology occurs in northwestern Florida and southern Alabama within boggy edges of cypress-titi-Nyssa on permanently wet substrates.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
The name Eriocaulon septangulare Withering, widely used for this species, is invalid (H. N. Moldenke 1937). Some (T. G. Tutin et al. 1964–1980, vol. 5) retain E. aquaticum (Hill) Druce as the valid name if one accepts both North American and European plants as the same species (the alternative taken here). If North American plants are considered to be distinct from Eurasian ones, then the appropriate binomial for ours becomes E. pellucidum Michaux.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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