Sideritis macrostachyos has branchedwoody stems. The thick, wrinkled leaves are petiolate and Glossary of [leaf morphology#crenulate|crenulate] in outline. The upper leaves are oval, the lower ones very large and more rounded. The upper surface of the leaves is green, and ranges from pubescent in the upper leaves to almost glabrous in the lower leaves. The lower surface of the leaves is white with cottony down. The flowers are arranged in terminal spikes which are large, stiff and tufted in appearance. The individual flowers are sessile and arranged in tight whorls separated by small bracts. The seeds are small, brown and rounded.
Taxonomy
Sideritis macrostachyos was first described by Jean [Louis Marie Poiret|Jean Poiret] in 1811. The epithetmacrostachyos is correct as published by Poiret; stachyos is an adjective derived from Greek, whose masculine and feminine forms both end in -os. In some sources, it has been wrongly changed to macrostachya, or to macrostachys.