Xanthomendoza hasseana

Field Notes 2

No soredia. Lobes narrow, less than 1mm. Rhizines easily seen from above (looking down at upper surface), indicating X. hasseana. Note: Xanthoria sp. has much shorter rhizines not visible from above.

Description 3

 Thallus: foliose, forming small to medium-sized rosettes up to 3 cm wide or extensive colonies, loosely adnate, lobate; lobes: dorsiventral, flattened to convex, 0.3-0.9 mm wide; tips: rotund to pointed, 0.1-0.4 mm wide; upper surface: yellow to light orange, smooth to shiny, not sorediate; medulla: white, reticulate, with short hyphae; lower surface: white, smooth to somewhat wrinkled, with abundant long, white to yellow rhizines; Apothecia: common, laminal, stipitate, up to 3.5 mm in diam.; margin: smooth with more or less abundant cilia; disc: orange; epihymenium: brown, c. 10 µm thick; hymenium: hyaline below, 70-90 µm tall;paraphyses: simple or branched, cylindrical, septate; asci: clavate, 8-spored; hypothecium: hyaline to pale brown, 25-75 µm thick; ascospores: ellipsoid, polarilocular, hyaline, 14-20 x 6-10 µm; septum: 4-10 µm wide; Pycnidia: common, immersed to protruding, darker than upper surface; conidia: bacilliform, 3-4.2 x 1-1.5 µm; Spot tests: upper surface K+ purple, C-, KC-, P-; Secondary metabolites: parietin (major), fallacinal (major), emodin, teloschistin (major) and parietinic acid.; Habitat and ecology: on bark, occasionally on rock or detritus, in rather humid microclimates; World distribution: boreal and temperate regions of the Americas, and Asia(?); Sonoran distribution: coastal regions of southern California.; Notes: Xanthomendoza hasseana is similar to X. montana, but X. hasseana has slightly longer and narrower lobes that are usually lighter orange pigmented, smaller and more distinctly ellipsoid spores with a wider septum. In X. hasseana the rhizines as well as the cilia on the thalline margin of the apothecia are usually longer. The distribution areas of the two species seem not to overlap, because X. montana is only reported from higher elevations inland. Xanthoria polycarpa has more convex and narrow lobes and usually the apothecia cover a greater part of the thallus. Important characters are the conidia, which are ellipsoid and produced in rather inconspicuous pycnidia in Xanthoria polycarpa; whereas they are bacilliform and produced in more conspicuous pycnidia in X. hasseana. 

Sources and Credits

  1. (c) CALS, some rights reserved (CC BY-NC-ND), uploaded by CALS
  2. (c) CALS, some rights reserved (CC BY-SA)
  3. (c) Lichen Unlimited: Arizona State University, Tempe., some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/10548809

More Info

Range Map

iNat Map

Color orange
Form foliose
Morphological feature apothecia, rhizines
Substrate bark