Cladoniaceae (Ahti, 2000)

Yánez-Ayabaca, A., Ahti, T. & Bungartz, F., 2013, The Family Cladoniaceae (Lecanorales) in the Galapagos Islands, Phytotaxa 129 (1), pp. 1-33 : 3

Key to species of the Cladoniaceae in the Galapagos Islands

1. Primary thallus granulose, evanescent, never squamulose; podetia generally 4–12 cm tall, always densely branched, typically forming cushions or mats (“reindeer lichens”), always ascyphose, lacking soredia, granules or microsquamules ............................................................................................................................................................................ 2

- Primary thallus squamulose, generally persistent, rarely evanescent; podetia present or not, if present, usually 1–3 (– 5) cm tall, simple or branched, scyphose or blunt; commonly sorediate, granulose or microsquamulose................... 5

2. Main thallus corticate, not originating from ascocarpous hyphae (pseudopodetia), with ellipsoid perforations, deep brown or pale yellowish brown, 4–5 cm tall....................................................................................... Cladia aggregata

- Main thallus ecorticate or with discontinuous cortex, originating from ascocarpous hyphae (true podetia), lacking perforations, whitish gray or yellowish gray, not distinctly brown, typically> 5 cm tall ............................................ 3

3. P+ orange red (fumarprotocetraric acid); podetia apically branched, with brownish to blackening necrotic tips; pycnidia with red jelly ......................................................................................................................................... C. arcuata

- P– (fumarprotocetraric acid absent); podetia apically branched, but tips ±concolorous with the podetia; pycnidial hyaline jelly never red .................................................................................................................................................. 4

4. Principal axes clearly differentiated because of their anisotomic branching pattern; ramifications dichotomous, rarely trichotomous, generally sparsely branched .......................................................... C. arbuscula subsp. boliviana

- Principal axes indistinct because of their isotomic branching pattern; ramification principally trichotomous, very rarely also dichotomous, densely branched .................................................................................................. C. confusa a. Podetia yellowish to greenish gray, with usnic acid........................................................ C. confusa f. confusa b. Podetia ash gray with brownish gray tips, lacking usnic acid ......................................... C. confusa f. bicolor

5. Podetia absent; primary thallus dominant .................................................................................................................... 6

- Podetia present; primary thallus persistent, but not dominant ..................................................................................... 8

6. Medulla C+ green (strepsilin) ..................................................................................................................... C. strepsilis

- Medulla C− (strepsilin absent) ..................................................................................................................................... 7

7. Squamules thick, short, laciniate; surface rugulose, often cracked, typically epruinose, rarely pruinose; lower side not cottony, always lacking soredia ..................................................................................................... C. corymbosula