About 300; see text
Stachys is one of the largest genera in the flowering plant family Lamiaceae. Estimates of the number of species in the genus vary from about 300, to about 450. The type species for the genus is Stachys sylvatica. Stachys is in the subfamily Lamioideae. Generic limits and relationships in this subfamily are poorly known.
The distribution of the genus covers Europe, Asia, Africa, Australasia and North America. Common names include heal-all, self-heal, woundwort, betony, lamb's ears, and hedgenettle. Wood betony, Stachys officinalis, was the most important medicinal herb to the Anglo-Saxons of early medieval Great Britain.
Stachys was named by Linnaeus in Species Plantarum in 1753. The name is derived from the Greek word σταχυς (stachys), meaning "an ear of grain", and refers to the fact that the inflorescence is often a spike. The name woundwort derives from the past use of certain species in herbal medicine for the treatment of wounds.
Stachys species are used as food plants by the larvae of some Lepidoptera species including the Coleophora case-bearers C. auricella (recorded on S. officinalis), C. lineolea and C. wockeella (feeds exclusively on S. officinalis).
Stachys is a genus of shrubs and annual or perennial herbs. The stems vary from 50–300 cm (20–120 in) tall, with simple, opposite, triangular leaves, 1–14 cm (0.39–5.5 in) long with serrate margins. In most species, the leaves are softly hairy. The flowers are 1 to 2 cm (0.39 to 0.79 in) long, clustered in the axils of the leaves on the upper part of the stem. The corolla is 5-lobed with the top lobe forming a 'hood', varying from white to pink, purple, red or pale yellow.
In Europe, Stachys can be found growing in wastelands, grasslands and woodland edges. All-heal thrives in any damp soil in full sun or in light shade. Plants are apt to become troublesome weeds in turf that is at all damp. Sow seed in very early spring in a flat outdoors, or give a short cold and moist conditioning treatment before sowing in a warm place. Growing from 1 to 2 feet high, with creeping, self-rooting, tough, square, reddish stems branching at leaf axis. The leaves are lance shaped, serrated and reddish at tip, about an inch long and 1/2 inch broad, grow on short stalks in opposite pairs down the square stem. The flowers grow from a clublike, somewhat square, whirled cluster, immediately below this club are a pair of stalkless leaves standing out on either side like a collar. Flowers are two lipped and tubular, the top lip is a purple hood, and the bottom lip is often white, it has three lobes with the middle lobe being larger and fringed upwardly. Flowers bloom at different times depending on climate and other conditions. Mostly from June to August. Gather whole plant when flowers bloom, dry for later herb use. Leaves and small flowers are edible.
Used as a medicine for centuries throughout the world, and for a wide variety of ailments, Woundwort has been viewed by herbalists as something of a panacea. It does however have some medicinal uses that are constant. The plant's most useful constituents are betulinic acid, D-camphor, delphinidin, hyperoside, manganese, oleanolic acid, rosmarinic acid, rutin, ursolic acid, as well as various saponins and tannins. The whole plant is medicinal as an alterative, antibacterial, antipyretic, antiseptic, antispasmodic, astringent, carminative, diuretic, febrifuge, hypotensive, stomachic, styptic, tonic, vermifuge and vulnerary. A cold water infusion of the freshly chopped or dried and powdered leaves makes a refreshing beverage, while a weak infusion of the plant can be used as a medicinal eye wash for sties and pinkeye. It is taken internally as a medicinal tea in the treatment of fevers, diarrhea, sore mouth and throat, internal bleeding, and weaknesses of the liver and heart.
The distinction between Stachys and other genera is unclear and has varied from one author to another. In 2002, a molecular phylogenetic study showed that Stachys officinalis is not closely related to the rest of the genus. This study also found six other genera to be embedded within Stachys as it is currently circumscribed. The embedded genera are Prasium, Phlomidoschema, Sideritis, Haplostachys, Phyllostegia, and Stenogyne.
Selected species 
Formerly placed here 
- Agastache foeniculum (Pursh) Kuntze (as S. foeniculum Pursh)
- Leonurus japonicus Houtt. (as S. artemisia Lour.)
Stachys sylvatica (Hedge Woundwort)
|Wikimedia Commons has media related to: Stachys|
|Wikispecies has information related to: Stachys|
- "Genus: Stachys L.". Germplasm Resources Information Network. United States Department of Agriculture. 2006-11-03. Retrieved 2010-11-11.
- Raymond M. Harley, Sandy Atkins, Andrey L. Budantsev, Philip D. Cantino, Barry J. Conn, Renée J. Grayer, Madeline M. Harley, Rogier P.J. de Kok, Tatyana V. Krestovskaja, Ramón Morales, Alan J. Paton, and P. Olof Ryding. 2004. "Labiatae" pages 167–275. In: Klaus Kubitzki (editor) and Joachim W. Kadereit (volume editor). The Families and Genera of Vascular Plants volume VII. Springer-Verlag: Berlin; Heidelberg, Germany. ISBN 978-3-540-40593-1
- David J. Mabberley. 2008. Mabberley's Plant-Book third edition (2008). Cambridge University Press: UK.
- Stachys In: Index Nominum Genericorum. In: Regnum Vegetabile (see External links below).
- Carolus Linnaeus. 1753. Species Plantarum 2:580. Laurentii Salvii. (see External Links below).
- Umberto Quattrocchi. 2000. CRC World Dictionary of Plant Names volume I, page 91. CRC Press: Boca Raton; New York; Washington, DC;, USA. London, UK. ISBN 978-0-8493-2673-8 (set). (see External links below).
- Charlotte Lindqvist and Victor A. Albert. 2002. "Origin of the Hawaiian endemic mints within North American Stachys (Lamiaceae)". American Journal of Botany 89(10):1709–1724.
- "GRIN Species Records of Stachys". Germplasm Resources Information Network. United States Department of Agriculture. Retrieved 2010-11-11.