| Lichen determination keys
- podetiate lichens of highland Ecuador -
Key to lichens with PODETIA (incl. pseudopodetia)
(genera Baeomyces, Cladia, Cladina, Cladonia, Dibaeis, Phyllobaeis )
for the highlands of Ecuador (above 2500 m)
with chemical guide to the Cladina and Cladonia species
by H. Sipman, Berlin, 6 August 1997
This unpublished key was prepared for a training course and is placed on the net to prevent it from getting forgotten in a drawer. It may be of some use to my fellow lichenologists. Comments are welcome at email@example.com.
1a Primary thallus (when present) fruticose, very similar to the (pseudo)podetia, not conspicuously foliose; cephalodia usually present; usually growing on rock, often firmly attached STEREOCAULON (key) b Primary thallus (when present) crustose or foliose, clearly distinct from the (pseudo)podetia, greenish above and white below; cephalodia absent; never firmly attached to rock 2 2a Primary thallus crustose, always present; podetia usually under 10 mm long; apothecium discs pink or occasionally brown 3 b Primary thallus squamulose, or absent; podetia often long, up to c. 10 cm; apothecium discs bright red or brown, rarely pink 9 3a Apothecium discs brown; schizidia or soredia often present Baeomyces rufus (Huds.) Rebent. b Apothecium discs pink; no schizidia or soredia 4 4a (genus DIBAEIS) Apothecia flat, shortly stalked (podetium about as long as apothecium disc width) Dibaeis absoluta (Tuck.) Kalb & Gierl b Apothecia convex from the beginning; podetium mostly much longer than the apothecium disc width 5 5a Thallus granular to warty 6 b Thallus smooth or slightly granular 7 6a Thallus with scattered, white, c. 0.5 mm wide warts; podetia 1-4 mm long, mostly smooth Dibaeis holstii (Müll. Arg.) Kalb & Gierl b Thallus densely granular, granules c. 0.2 mm wide and pale gray; podetia 2-11 mm long, with granular surface Dibaeis columbiana (Vain.) Kalb & Gierl 7a Thallus dark gray, thick, areolated; apothecia 4-7 mm wide Dibaeis umbrelliformis Kalb & Gierl b Thallus pale gray, thin and not areolated; apothecia 2-4 mm wide 8 8a Apothecia elongate, gradually narrowed towards the podetium; podetia 1-8 mm long Dibaeis fungoides (Sw.) Kalb & Gierl b Apothecia globose, suddenly narrowed towards the podetium; podetia 1-3 mm long Dibaeis globulifera Kalb & Gierl 9a Apothecia pink, usually present; podetia to c. 2 mm long 10 b Apothecia bright red or (dark)brown, often absent; podetia usually over 10 mm long 11 10a (genus PHYLLOBAEIS) Primary thallus squamules much longer than wide and deeply lobed; mostly above 3000 m Phyllobaeis imbricata (Hook. in Kunth) Kalb & Gierl b Primary thallus squamules about as long as wide, crenulated; mostly below 3000 m Phyllobaeis erythrella (Mont.) Kalb 11a Podetial wall without compact inner layer, with many rounded perforations; cortex cartilaginous and occupying about half of the wall thickness; primary thallus usually absent 12 b Podetial wall with distinct, compact inner layer occupying half of the wall thickness or more, without or with occasional slit- like perforations or open axils; cortex thin or absent; primary thallus often present, sometimes without podetia 13 12a (genus CLADIA) Inner space of podetial cylinder empty; common species of roadbanks and many other habitats Cladia aggregata (Sw.) Nyl. b Inner space of podetial cylinder with thin arachnoid, dark gray tissue of scattered hyphae; rare bog species Cladia fuliginosa Filson 13a Primary thallus squamules always lacking; compact podetial cortex always lacking, surface woolly; podetia richly branched 14 b Primary thallus squamules often present; compact podetial cortex often present, at least at the base of the podetia, and there surface smooth 17 14a (genus CLADINA) Podetia predominantly trichotomously branching, usually with a pale yellow tinge, forming rounded heads, P- Cladina confusa (R. Sant.) Follm. & Ahti b Podetia predominantly di- or tetrachotomously branching, whitish gray or pale yellowish gray, growing in flat-topped mats; P+ red 15 15a Podetia pale yellowish gray, with usnic acid (K-, KC+ yellow) Cladina boliviana Ahti b Podetia whitish gray, with atranorin (K+ pale yellow, KC-) 16 16a Podetia with weakly violet tinge, often strongly browned; tips bluntish; hyaline pycnidial slime; preferably in open peat bogs Cladina rangiferina (L.) Nyl. ssp. abbayesii (Ahti) W. Culb. b Podetia without violet tinge, not browned; tips subulate; red pycnidial slime; in light forest Cladina arcuata (Ahti) Ahti & Follm. 17a (genus CLADONIA) Primary thallus squamules large and dominant (in well developed plants!) 18 b Podetia dominant, primary thallus squamules often small and evanescent 21 18a Thallus P+ red, C- 19 b Thallus P-, C+ green Cladonia strepsilis (Ach.) Grognot 19a Thallus squamules sorediate; podetia, when present, hardly standing out above the erect thallus squamules Cladonia nana Vain. b Thallus squamules not sorediate; podetia, when present, raised above the spreading thallus squamules 20 20a Thallus often with white, marginal cilia; podetia often present, subulate, with fragile, elongate, downward pointing squamules; atranorin absent (K- or K+ brownish) Cladonia ceratophylla (Sw.) Spreng. b Thallus without cilia; podetia usually absent, scyphose, without fragile squamules; atranorin present (K+ pale yellow) Cladonia macrophyllodes Nyl. 21a Most or all podetia scyphi-forming; scyphi usually more than twice as wide as their stalks 22 b Podetia subulate, more or less branched; podetium tips may occasionally show minute scyphi hardly wider than the podetium 35 22a Scyphi sprouting from the center, often forming chains of several scyphi on top of each other 23 b Scyphi sprouting from the margin, usually single 27 23a Podetium surface with fragile scales or granules, or sorediate 24 b Podetium surface smooth 25 24a Podetium surface with fragile scales, at least on underside of scyphi margins; podetia composed of several, wide, short-stalked scyphi Cladonia andesita Vain. b Podetium surface granular to sorediate; podetia composed of few scyphi, often with subulate tips Cladonia aleuropoda Vain. 25a Margins of the scyphi with elongated, blackening, often 1-3 times branching teeth Cladonia calycantha Nyl. b Margins of the scyphi crenulate or shortly teethed 26 26a Scyphi long and slender, c. 5-10 mm long and 0.5-3 mm wide; podetia composed of few scyphi, often subulate; usually P- Cladonia isabellina Vain. b Scyphi wider, 2-6 mm wide; podetia usually composed of many scyphi, not subulate Cladonia rappii A. Evans 27a Podetia with pale yellowish tinge, containing usnic acid (KC+ yellow); apothecia red, when present Cladonia coccifera (L.) Willd. b Podetia gray brown, without usnic acid (KC-); apothecia brown or red 28 28a Podetia P+ red, K- or K+ brownish (fumarprotocetraric acid), rarely P-, K-, or K+ pale yellow; hypothallus whitish, inconspicuous 29 b Podetia P+ yellow, K+ yellow (thamnolic acid); hypothallus yellow, conspicuous (if K-, psoromic acid, see C. dactylota) 33 29a Podetia P+ red, K+ brownish or rarely K+ pale yellow 30 b Podetia P-, K- Cladonia imbricarica Kristinsson 30a Podetia sorediate, with more or less ecorticate granules 31 b Podetia not sorediate, with corticate, large granules only Cladonia pocillum (Ach.) Grognot 31a Podetia finely sorediate on the scyphi margins, corticate at the stalk, K+ yellow (atranorin) Cladonia humilis (With.) J.R. Laund. b Podetia sorediate to granular, also on the stalks, K- or K+ brownish (no atranorin) 32 32a Podetia finely sorediate on scyphi and stalk; soredial masses often abraded and showing white podetium stereome Cladonia subsquamosa Kremp. b Podetia coarsely sorediate on scyphi only, without white, abraded spots Cladonia chlorophaea (Flk. ex Sommerf.) Spreng. (including some very similar but ecologically distinct species, which require more complicated chemical tests for recognition, like Cladonia cryptochlorophaea Asah. with cryptochlorophaeic acid, and Cladonia grayi Merr. with grayanic acid). 33a Podetia sorediate; scyphi narrow Cladonia leprocephala Ahti & Stenroos b Podetia not sorediate, surface warty or with corticate granules 34 34a Podetia in part with narrow scyphi, in part subulate Cladonia microscypha Ahti & S. Stenroos b Podetia all with wide scyphi Cladonia meridensis Ahti & S. Stenroos 35a Podetia sorediate, soredia sometimes mixed with granules or squamules, often abraded and showing white stereome, simple or scarcely branched 36 b Podetia without soredia, either with corticate granules or fragile scales or squamules, often abraded, or with smooth surface, scarcely or more richly branched 43 36a Usnic acid present, colour yellowish 37 b Usnic acid absent, colour grey to brown 38 37a Axils of branched podetia often perforated and somewhat widened; apothecia brown, rarely present Cladonia scholanderi Des Abbayes b Axils of branched podetia closed; apothecia red, often present Cladonia leprocephala Ahti & Stenroos 38a Axils of branched podetia often perforated and somewhat widened Cladonia granulosa (Vain.) Ahti b Axils of branched podetia closed 39 39a Soredia mostly in woolly clumps near the podetium tips; P+ yellow (psoromic acid) Cladonia dactylota Tuck. b Soredia dispersed over most of the podetium length, not woolly; P+ red, yellow or P- (no psoromic acid) 40 40a Podetia P+ yellow, K+ yellow; apothecia and pycnidia, when present, red Cladonia macilenta Hoffm. b Podetia P+ red, K+ brownish or K-; apothecia and pycnidia, when present, brown 41 41a Podetium stereome surface distinctly grooved; podetia often largely abraded and showing a whitish to brownish stereome; apothecia usually produced directly on subulate podetium tips Cladonia corniculata Ahti & Kashiwadani b Podetium stereome smoothly rounded; podetia mostly covered by greenish masses of soredia and/or cortex; apothecia stalked on terminal scyphi 42 42a Podetia corticate in lower half and on lower side of scyphi; sometimes with rounded soralia on transition between corticate and sorediate part; soredia not coalescent Cladonia ochrochlora Flk. b Podetia corticate only near extreme base, without rounded soralia; soredia often coalescent into tiny squamules Cladonia subradiata (Vain.) Sandst. 43a Podetia to c. 1 cm long, always bearing apothecia 44 b Podetia usually several cm long, rarely a few bearing apothecia 45 44a Apothecia red; podetia very irregularly shaped; cortex of squamules thick c. one third of total thickness Cladonia lopezii S. Stenroos b Apothecia brown; podetia cylindrical, often once or a few times verticillate-branched, all branches bearing apothecia; cortex of squamules thin as usual Cladonia corymbosula Nyl. 45a Podetia with corticate granules or fragile scales or squamules, usually decorticated over much of their length 46 b Podetia without fragile squamules, mostly corticate 50 46a Axils of podetium branchings often perforate and dilated; with squamules, without corticate granules or fragile scales (when corticate granules present, see C. granulosa, lid 38) Cladonia squamosa (Scop.) Hoffm. b Axils of podetium branchings closed; mostly with fragile scales or squamules, sometimes also corticate granules 47 47a Podetia mostly with naked, glassy, pale brown stereome; fragile squamules usually elongate and pointing downward: apothecia and pycnidia, when present, red; P+ yellow or P- Cladonia didyma (Fée) Vain. b Podetia with mostly tomentose, white, abraded podetia; fragile squamules often short and scale-like; apothecia and pycnidia, when present, brown; P+ red 48 48a Podetia with scattered, corticate patches, at tips forming small scyphi, often very whitish, K+ pale yellow Cladonia mexicana Vain. b Podetia without cortex, except sometimes at the base, at tips always subulate, usually pale brownish; K+ brownish 49 49a Podetia mostly subulate and unbranched, or with divaricate branchlets, rarely with apothecium; stereome very hard, over most of its length naked Cladonia cartilaginea Müll. Arg. b Podetia usually cylindrical and branched, or with terminal apothecium, stereome less hard, tomentose where free, sometimes slightly glassy Cladonia corymbites Nyl. 50a Podetia yellowish to greenish grey, with usnic acid; KC+ yellow Cladonia aff. uncialis b Podetia grey to brownish, without usnic acid, KC- 51 51a Podetia P+ red, K+ brownish; podetia without perforated and widened axils, fertile branches with lateral splits Cladonia furcata (Huds.) Schrad. b Podetia P-, K- or P+ yellow, K+ yellow: podetia often with widened and dilated axils. Cladonia crispata (Ach.) Flot.
List of Cladina and Cladonia species, with their principal lichen substances and colour reactions
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