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Related to prothallus: sorus, indusium, homosporous


 (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.
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References in periodicals archive ?
The prothalli were bisexual although the antheridia and archegonia occurred on each prothallus asynchronously.
Thallus evident, areolate to subsquamulose; prothallus lacking 3 2.
These palynomorphs are characterized by openings or scars (apertures) through which the pollen tube and prothallus emerged.
Spore germination followed the Vittaria-type development, whereas prothallus growth followed the Aspidium-type development.
The prothallus is thin, has a leaf-like structure and is photosynthetic and cordate.
After a period of dormancy, each microspore germinates and grows into a prothallus that in turn produces ciliated, male gametes (antherozoids).
After DG gametophytes reached the prothallus stage, they were wetted erratically upon drying with dd[H.
Rhizoids developed mainly on the ventral surface of the young prothallus but they also could be observed on the mature prothallial margins.
Frond, frond microcuttings, and prothallus explants were evaluated on Knop regeneration medium supplemented with 1g [L.
2D), which led to the development of a pre-cordate prothallus (Fig.
The germination of a great number of fern spores is promoted by light (Miller, 1968) and nutrients, water and mild temperatures are implicated in the growth and development of the prothallus and in sporophyte formation (Fernandez et al.