What does chlorosis mean?
Chlorosis is a condition in which plant leaves fail to produce enough chlorophyll, causing them to lose their normal green colour and appear pale yellow. It is not a disease itself but a visible symptom of an underlying problem — most often a nutrient deficiency such as lack of iron, nitrogen, or magnesium, though poor drainage, root damage, soil alkalinity, or infection can also be responsible. Gardeners and agronomists describe patterns such as interveinal chlorosis, where tissue between the veins yellows first, to help pinpoint the cause. The word derives from the Greek 'chloros', meaning pale green, and entered English in the seventeenth century. Historically it also named a form of iron-deficiency anaemia in young women, once romantically but inaccurately dubbed 'greensickness'. Today chlorosis survives mainly as a precise, technical term of horticulture and plant science, valued for describing exactly how a leaf loses its green.
A condition in plants marked by inadequate chlorophyll production, resulting in abnormally pale or yellow leaves, typically caused by nutrient deficiency or environmental stress.
"The gardener corrected the chlorosis with a dose of chelated iron."
The standard plural is 'chloroses'.
(Historical, medicine) A former name for iron-deficiency anaemia occurring especially in adolescent girls, characterised by pallor and weakness; also called greensickness.
"Nineteenth-century medical texts devoted whole chapters to the diagnosis and treatment of chlorosis."
This sense is now obsolete; modern medicine simply diagnoses iron-deficiency anaemia.
Rarely used, since chlorosis is normally treated as an uncountable condition; when a plural is needed (e.g. comparing cases across species), 'chloroses' is standard.
"Different mineral deficiencies produce distinguishable chloroses in the same crop."
Once nicknamed 'the virgin's disease', chlorosis was blamed for generations on lovesick young women — before doctors realised it was simply iron deficiency all along.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of chlorosis
Chlorosis comes from New Latin, borrowed from Greek 'chlorōsis' (a becoming green), from 'chloros' meaning pale green or yellowish-green — the same root that gives us chlorine, chlorophyll, and chloroplast. The word was adopted into English medical writing in the early 17th century for the anaemia then called greensickness, and was later extended by analogy to the yellowing of plant foliage. Its adjective form, chlorotic, follows the same derivation.
Related word forms
How chlorosis is actually used
In modern usage the word belongs almost entirely to botany, horticulture, and plant pathology; its medical sense is historical. The adjective form is 'chlorotic'. Register is technical/formal.
Easily confused with chlorosis
Sclerosis is the abnormal hardening of body tissue (as in multiple sclerosis), whereas chlorosis is the yellowing of plant leaves or an obsolete name for a type of anaemia.
Chlorination is treatment with chlorine (as in disinfecting water), while chlorosis refers to loss of green colour in foliage.