18.
Lysimachia thyrsiflora
Linnaeus, Sp. Pl. 1: 147. 1753.
Swamp or tufted loosestrife, lysimaque thyrsiflore
Lysimachia capitata
Pursh;
L. capitellata
Rafinesque;
L. subcapitata
Rafinesque;
Lysimachusa thyrsiflora
(Linnaeus) Pohl;
Naumburgia thyrsiflora
(Linnaeus) Reichenbach;
Nummularia thyrsiflora
(Linnaeus) Kuntze;
Thyrsanthus palustris
Schrank
Stems
erect, simple, 3-8 dm, pubescent distally; rhizomes stout; bulblets absent.
Leaves
opposite to subopposite or whorled; petiole absent or 0.1-0.2(-0.4) cm, eciliate; blade lanceolate or linear-lanceolate to elliptic, 5-16 × 0.5-6 cm, base truncate to rounded or cuneate, not decurrent, margins entire, plane, eciliolate, apex acute to obtuse, surfaces punctate, glabrous or sometimes sparsely pubescent abaxially; venation pinnate.
Inflorescences
axillary, racemes, 1-3 cm.
Pedicels
0.1-0.4 cm, stipitate-glandular or pubescent.
Flowers:
sepals 5-7(-9), calyx streaked with dark resin canals, 1-2.8 mm, glabrous, lobes narrowly lanceolate, margins thin; petals 5-7(-9), corolla light yellow, streaked with black or reddish-brown resin canals, somewhat funnelform, 3-7 mm, lobes with margins entire, apex rounded to acuminate, eglandular; filaments distinct or connate ca. 0.2 mm, nearly 2 times as long as corolla; staminodes absent (rarely staminodelike minute teeth present between fertile filaments).
Capsules
2-3 mm, dark-punctate, glabrous.
2
n
= 40, 42, 54.
Flowering spring-summer. Bogs, swamps, marshes, wet woods; 0-2000 m; Alta., B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.W.T., N.S., Ont., P.E.I., Que., Sask., Yukon; Alaska, Calif., Colo., Conn., Idaho, Ill., Ind., Iowa, Kans., Maine, Md., Mass., Mich., Minn., Mo., Mont., Nebr., N.H., N.J., N.Y., N.Dak., Ohio, Oreg., Pa., R.I., S.Dak., Utah, Vt., Wash., W.Va., Wis., Wyo.; Eurasia.
Lysimachia thyrsiflora
is known to hybridize readily with 17.
L. terrestris
(see discussion under the latter).
