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Yellow fairy cups or Lemon Disco Fruit body

bisporella citrina


Bisporella citrina (Batsch ex Fr.) Korf & Carpenter syn. Calycella citrina ([Hedwig.] Fr.) Boud. Lemon Disco Fruit body 0.5–3mm across, saucer-shaped tapered below to a small base, bright yellow becoming orange-yellow when old or dried, exterior smooth. Asci 135×10µ. Spores elliptical, containing two oil drops at each end, 9–14×3–5µ, often becoming one-septate. Habitat gregarious in dense swarms on dead wood of deciduous trees. Season autumn. Common. Not edible. Found In Europe and north America.


----My optometrist tells me that "at about 40" is when men can expect to start peering over the tops of their glasses to see tiny things (he says that women, in one of the few cases where they get a raw deal in comparison to men, reach this stage in their early thirties). Well, Bisporella citrina is decidedly one of those tiny things requiring an OMHT (Old Man Head Tilt) to bring into focus, if one has crossed my optometrist's line in the sand; it has a maximum cap size of about three millimeters. ----For those young enough to examine the mushroom casually, the defining features are the diminutive size, the bright yellow color, and the habitat in clusters on decaying wood. Microscopic features should be verified, however, if your identification effort is more than casual. The mushroom is widely distributed and common but often (obviously) overlooked. ----Description: --Ecology: Saprobic on decaying logs and stumps of hardwoods and conifers; growing in dense clusters; summer and fall (over winter in warmer areas); widely distributed in North America. --Fruiting Body: Cup shaped to disc shaped; up to 3 mm across; smooth above and below; with a tiny tapering stem or nearly without a stem; smooth; uniformly bright yellow. --Microscopic Features: Spores 9-14 x 3-5 µ; elliptical; with an oil droplet at each end; smooth; often septate by maturity. Asci 100-135 x 7-10 µ. Paraphyses narrowly cylindric, with rounded or slightly clavate apices. ( )


---Scientific name: Bisporella citrina (Batsch : Fries) Korf & Carpenter ---Derivation of name: Citrin- means "lemon-yellow." ---Synonyms: Helotium citrinum; Calycella citrina ---Common name(s): Yellow fairy cups ---Phylum: Ascomycota ---Order: Helotiales ---Family: Helotiaceae ---Occurrence on wood substrate: Saprobic; in clusters on decaying wood; summer through fall. ---Dimensions: Cups are 1-3 mm wide; stalkless or with thick, stalk-like base. ---Sterile outer surface: Bright lemon-yellow to golden- yellow; smooth. ---Fertile inner surface: Same coloration as sterile surface; smooth. ---Edibility: Unknown ---Comments: Although individually tiny, these fungi often occur in such large numbers that they become quite conspicuous ----( )

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1 Comment

Jacob Gorneau
Jacob Gorneau 10 years ago

They look like golden raisins!

Spotted by

Horst aan de Maas, Limburg, Netherlands

Spotted on Jan 14, 2012
Submitted on Jan 18, 2012

Spotted for Mission

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