Iresine rhizomatosa Standl.

Iresine rhizomatosa has occasionally been called I. celsioides Linnaeus, a misapplication of that name.

Herbs, perennial, 3-10 dm, stoloniferous. Stems erect, largely simple proximal to inflorescences, villous or glabrous. Leaves op-posite; blade ovate to elliptic, 6-15 × 2-7 cm, apex acute to long acuminate, sparsely pubescent. Inflorescences: panicles 7-30 cm; bracts and bracteoles of staminate and pistillate flowers shorter than tepals. Flowers: tepals white, ovate, 1-1.3 mm, hyaline, apex acute to acuminate, densely lanate. Utricles exerted from tepals, greenish white, ovoid, 1.1-1.5 mm, apex rounded. Seeds 0.5-0.8 mm.

Ala., Ark., Fla., Ga., Ill., Ind., Kans., Ky., La., Md., Miss., Mo., N.C., Okla., S.C., Tenn., Tex., Va.

Flowering fall.

Sandy alluvial soils of low woods, depressions, sand dunes, along rivers, sandy bluffs; 0-200m.

Iresine rhizomatosa Standley, Proc. Biol. Soc. Wash. 28: 172
1915.
Iresine celosioides Michx. Fl. Bor. Am. 2: 244. 1803. Not J. celosioides L. 1763.
Iresine paniculata Uline & Bray, Bot. Gaz. 21 : 353, in part. 1896. Not Celosia paniculata L. 1753.
Perennial from slender elongate horizontal rootstocks; stems commonly solitary, herbaceous, stout, erect, 3-15 dm. high, usually simple up to the inflorescence, sparsely villous with short hairs, more densely villous at the nodes, sometimes glabrous throughout, the nodes slightly swollen, the internodes 5-14 cm. long; petioles slender, 0.8-3 cm. long; leaf-blades
+
broadly deltoid-ovate to ovate or elliptic-oval, 6-15 cm. long, 2-7 cm. wide, acute or rather abruptly acute to long-acuminate, or the lowermost very rarely obtuse at the apex, truncate to acute at the base, usually slightly decurrent, thin, bright-green, bearing a few scattered short stout hairs on the upper surface along the veins, sparsely pubescent beneath with short stout soft hairs, or sometimes nearly glabrous; pistillate panicles 7-30 cm. long and 2.5-20 cm. broad, much branched, the stoutish branches erect or ascending, usually dense, sparsely villous, the spikelets alternate or opposite, stout, densely flowered, 0.5-2 cm. long, the staminate panicles often laxly branched and with longer spikelets; bracts white, equaling or somewhat shorter than the sepals, ovate to ovate-orbicular, acute or acutish; sepals ovate-oblong or oblong, acute or acuminate, 1-1.3 mm. long, faintly 1-nerved, white, the pistillate flowers bearing copious long white wool at the base ; lobes of the staminal cup nearly obsolete ; utricle equaling or commonly longer than the sepals; seed suborbicular, dark-red, shining, 0.5 mm. in diameter.
Type locality: Plummers Island, Montgomery County, Maryland. Distribution: Maryland to Kansas, central Texas, Tennessee, and Alabama.

Iresine rhizomatosa is a species of plant in the family Amaranthaceae. It is native to the Americas. In the United States, it has a spotty distribution, being concentrated in the Ozark and Ouachita Mountains and along the coast. It is often found in thin woods over sandy alluvial soil, often along rivers or dunes. It is a rhizomatous perennial that produces white flowers in the fall. It is dioecious, with male and female flowers on separate individuals.

Iresine rhizomatosa là loài thực vật có hoa thuộc họ Dền. Loài này được Standl. mô tả khoa học đầu tiên năm 1915.