(redirected from prothallic)
Also found in: Medical.


 (prō-thăl′əs) or pro·thal·li·um (-thăl′ē-əm)
n. pl. pro·thal·li (-thăl′ī) or pro·thal·li·a (-thăl′ē-ə)
A small, flat, delicate structure produced by a germinating spore and bearing sex organs. It is the gametophyte of ferns and some other plants.

[New Latin : pro- + Greek thallos, shoot (from thallein, to sprout).]

pro·thal′li·al (-lē-əl) adj.


(prəʊˈθæləs) or


n, pl -li (-laɪ) or -lia (-lɪə)
(Botany) botany the small flat free-living gametophyte that bears the reproductive organs of ferns, horsetails, and club mosses. It is either a green disc on the soil surface or it is colourless and subterranean
[C19: from New Latin, from pro- before + Greek thallos a young shoot]
proˈthallic, proˈthallial adj


(proʊˈθæl i əm)

n., pl. -thal•li•a (-ˈθæl i ə)
the gametophyte of ferns and related plants.
[1855–60; < Greek pro- pro-2 + thallíon, diminutive of thallós young shoot; see -ium2]
pro•thal′li•al, pro•thal′lic, pro•thal′line (-ˈθæl in, -aɪn) adj.
pro•thal′loid, adj.
Mentioned in ?
References in periodicals archive ?
m in diameter, are found inside the rhizoids; these hyphae occur near the rhizoid apex up to the prothallic cells of the gametophyte, where they branch out.
Arbuscular mycorrhizal fungi (AMF) produced inter- and intracellular hyphae on the gametophyte midrib and wings prothallic cells; hyphae branch dispersing over a bigger surface (Figs.
Spreng by Schmid and Oberwinkler (1995): the endophytic fungal hyphae were aseptate and spread inter- and intra-cellularly, they penetrated the host tissue through the rhizoids, developed vesicles in both the rhizoidal and the prothallic cells.