台灣植物誌 第二版 Flora of Taiwan, 2nd edition Vol. 1
Vascular plants with roots; aerial stems erect, grooved, jointed, hollow. Leaves without chlorophyll, united into a sheath at the nodes. Sporangia unilocular, borne on the back of peltate sporangiophores, arranged in a compact strobilus. Spores green, round, with 4 elaters.
5. EQUISETACEAE 木賊科
DEVOL, CHARLES E.
Rush-like perennial plants with long creeping rhizomes; aerial stems erect, grooved, jointed, without branches or with one to many branches at the nodes. Fertile and sterile stems both green and alike, or the fertile ones lacking chlorophyll; c.s. of internodes usually with a large central cavity (the centrum) and a smaller cavity under each groove (the vallecular canal), and a very small cavity under each ridge (the carinal canal); vascular tissues borne adjacent to carinal canals, the endodermis a continuous ring or of separate rings around each vascular bundle; silica borne on ridges of aerial stems, and stomata in the grooves; nodes with a sheath, bearing either persistent or deciduous teeth. Strobilus terminal on main stem or also borne on ends of branches; sporangia borne on the back of stalked sporangiophores. Spores round, green with 4 elaters. Gametophyte green, lobed. Chromosome number n = 108 for all reported species.
Only one living genus.
1. EQUISETUM L. 木賊屬
Characters of the family.
Twenty-three species, only one species with two subspecies in Taiwan.
1. Equisetum ramosissimum Desf., F1. Atlant. 2: 398. 1800; DeVol in Fl. Taiwan 1: 55. 1975.
Equisetum ramosissimum Desf. Var. taikankoense Yamamoto in Trans. Nat. Hist. Soc. Form. 20: 97.1930.
KEY TO SUBSPECIES
1. Lower sheaths with a dark brown band; teeth usually persistent; stem with an inner and outer continuous endodermis… 1a. E. ramossimum ssp. Ramossissimum
1. Sheaths green; teeth usually breaking off; c.s.of stem shows each vascular bundle with a separate endodermis… 1b. E. ramosissimum ssp. Debile
1a. ssp. Ramosissimum. 木賊
Stems unbranched or with 2-3 branches per node, 20-160 cm tall, 1-7 mm in diameter; stomata in 1-3 lines in the grooves; sheaths longer than wide, the lower sheaths with a brown band, the upper ones green; teeth 3-9 mm long, having brown centers with white margins, when broken off, leaving a brown