174
E. IMRE FRIEDMANN AND MARGALITH GALUN
Fig. 3. Cross section of epedaphic algal crust in Knervslakte (S. Africa). Upper
layer is dust, followed by a darker zone of Schizothrix sp. and below, a zone
of fungus hyphae. Redrawn after Vogel (1955).
Microcoleus vaginatus (Vauch.) Gom. which, due to its adaptability, inhabits a wide range of substrates of different salt and moisture contents.
Bolyshev lists from two localities (Kazakhskaya S.S.R. and Turkmenskaya
S.S.R.) 31 species of blue-green algae (10 Phormidum, 9 Lyngba, 4
Nostoc, 2 Oscillatoria, 2 Microcoleus, and 1 each of Aphanothece, Nodularia, Schizothrix, and Calothrix), 3 diatoms (Hantzschia, Navicula), 12
green algae (Chlamydomonas, Chlorococcum, Chlorella, Cystococcus,
Palmella, Protococcus, Scenedesmus), and a moss protonema. Takyr crusts
may become lichenized, and the lichens [most frequently Collema minor
(Pach.) Tomin] appear first in the cracks which border the polygonal crust
fragment. From here, they progressively advance, partly by the fungus
E. IMRE FRIEDMANN AND MARGALITH GALUN
Fig. 3. Cross section of epedaphic algal crust in Knervslakte (S. Africa). Upper
layer is dust, followed by a darker zone of Schizothrix sp. and below, a zone
of fungus hyphae. Redrawn after Vogel (1955).
Microcoleus vaginatus (Vauch.) Gom. which, due to its adaptability, inhabits a wide range of substrates of different salt and moisture contents.
Bolyshev lists from two localities (Kazakhskaya S.S.R. and Turkmenskaya
S.S.R.) 31 species of blue-green algae (10 Phormidum, 9 Lyngba, 4
Nostoc, 2 Oscillatoria, 2 Microcoleus, and 1 each of Aphanothece, Nodularia, Schizothrix, and Calothrix), 3 diatoms (Hantzschia, Navicula), 12
green algae (Chlamydomonas, Chlorococcum, Chlorella, Cystococcus,
Palmella, Protococcus, Scenedesmus), and a moss protonema. Takyr crusts
may become lichenized, and the lichens [most frequently Collema minor
(Pach.) Tomin] appear first in the cracks which border the polygonal crust
fragment. From here, they progressively advance, partly by the fungus