stroma

American  

[stroh-muh] / ˈstroʊ mə /

noun

plural

stromata

1. Cell Biology. the supporting framework or matrix of a cell.

2. Anatomy. the supporting framework, usually of connective tissue, of an organ, as distinguished from the parenchyma.

3. Mycology. (in certainfungi ) a compact mass of tissue, in or on which the fructifications may be developed.

4. Botany. the matrix of a chloroplast containing various molecules and ions.

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stroma British  

/ ˈstrəʊmə, strəʊˈmætɪk /

noun

1. the gel-like matrix of chloroplasts and certain cells

2. the fibrous connective tissue forming the matrix of the mammalian ovary and testis

3. a dense mass of hyphae that is produced by certain fungi and gives rise to spore-producing bodies

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Other Word Forms

• stromal adjective
• stromatic adjective
• stromatous adjective

Etymology

Origin of stroma

First recorded in 1825–35; from Late Latin strōma “mattress,” from Greek strôma “bed-covering”; akin to Latin sternere “to spread, strew, ” strātum ( stratum )

Example Sentences

The researchers examined 24 pancreatic cancer samples and found that the stroma, the connective tissue that supports the tumor, plays an active role in cancer progression rather than serving as a passive structure.

From Science Daily • Jan. 30, 2026

The light harvesting reactions take place in the thylakoid membranes, and the synthesis of sugar takes place in the fluid inside the inner membrane, which is called the stroma.

From Textbooks • Jun. 9, 2022

Once in the mesophyll cells, CO2 diffuses into the stroma of the chloroplast—the site of light-independent reactions of photosynthesis.

From Textbooks • Jun. 9, 2022

The fluid enclosed by the inner membrane that surrounds the grana is called the stroma.

From Textbooks • Jun. 9, 2022

Epichloë, which clothes the sheaths and halms of grasses with its stroma, at first snowy white and later ochre-yellow as the perithecia form, is another example.

From Disease in Plants by Ward, H. Marshall