7a. Equisetum ramosissimum subsp. ramosissimum
节节草(原亚种) jie jie cao (yuan ya zhong)
Equisetum elongatum Willdenow; E. ramosissimum var. glaucum Nakai; E. ramosissimum var. japonicum Milde; E. ramosissimum var. taikankoense Yamamoto; E. ramosum Lamarck & Candolle; E. sieboldii Milde; Hippochaete ramosissima (Desfontaines) Milde ex Bruhin; H. ramosissima var. japonica (Milde) Satou.
Plants small to medium-sized. Rhizome erect, creeping, or ascending, blackish brown, nodes and roots with few long yellowish brown trichomes or glabrous. Aerial stem perennial, monomorphic, green, 20-60 cm tall, 1-3 mm in diam. at middle, lower portion of main stem often branched, tufted; internodes 2-6 cm. Main stem 5-14-ridged; ridges arc-shaped abaxially, with a row of tubercles or small light brown cross grains; sheaths narrow and up to 1 cm, lower portion grayish green, upper portion grayish brown; sheath teeth 5-12, deltoid, teeth of middle portion grayish white or few teeth blackish brown, arc-shaped abaxially, margin (sometimes upper part) membranous, persistent, with conspicuous stomatal bands on sheath teeth. Lateral branches hard, cylindrical, 5-8-ridged; ridge glabrous or with 1 row of tubercles or small pale cross grains; sheath teeth 5-8, teeth of upper portion brown, lanceolate, leathery but membranous at margin, persistent. Strobilus shortly clavate or ellipsoid, 0.5-2.5 cm, 0.4-0.7 cm in diam. at middle, apex with small acute tip, sessile.
Forests, forest margins, under bushes, meadows, banks of rivers and streams; 100-3600 m. Anhui, Chongqing, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hainan, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, Nei Mongol, Ningxia, Qinghai, Shaanxi, Shandong, Shanxi, Sichuan, Taiwan, Xinjiang, Xizang, Yunnan, Zhejiang [Afghanistan, Bhutan, N India, Japan, Korea, Mongolia, Pakistan, Russia; Africa, C and SW Asia, Europe; introduced in North America (SE United States)].