Baden-Württemberg - Lichens of Wales

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The color intensity of the excipulum, epihymenium and hypothecium depends on the section selected. The color given in the keys, so far as possible, relates to that which would be perceived from a thin hand section. The structure of the excipulum is often only perceptible on really thin sections, at best on microtome sections of 15-20 µm thick. The height of the hymenium is measured from the base of the ascus to the outer boundary of the epihymenium, therefore including the epihymenium. The hymenium height corresponds to the height of the paraphyses. Here the outermost colored region of the hymenium is designated as the epihymenium, no matter where the color is located. The hymenium is commonly colorless. Sometimes rays of color penetrate deep into the hymenium. Paraphyses and Paraphyses-like Structures It is the practice, in the determination keys of this book, to call all sterile filamentous structures within the hymenium paraphyses. According to the developmental layering viewpoint one may therefore distinguish more forms of paraphyses-like structures. True paraphyses grow from the underlying region of the hymenium toward the upper and are from the first free at the ends. Paraphysoids, in contrast to the true paraphyses, originate largely from ascus production; they are often especially thin, the cell septa wide apart. Pseudopara-physes grow from the upper part perithecia-like fruiting bodies developing between the asci and binding to the base of the hymenium; they are commonly regularly septate, relatively thick, branched and bound to one another. Diagnosis of genera depend upon the various types of “paraphyses.” The paraphyses may be thickened at the tip or not thickened, may be branching or reticulate bound (anastomosing). Simple, entirely, or predominantly unbranched paraphyses are known. The relationships are often difficult to judge. Adding KOH often results in greater clarity. Weakly cemented paraphyses are loosened from one another by a slight pressure on the cover glass, at least after addition of KOH (characteristic “paraphyses easily free”). In rare instances paraphyses are missing or deliquescing and are then only to be recognized in the young. Periphyses occur in perithecia; they are filamentous hyphae, which project from the mouth region (ostiole). Asci The structure of the ascus has attained great importance for systematics in recent years. This is reflected also in the diagnostics of lichens. Fissitunicate (or bitunicate) asci have walls whose layers are loose from one another at the opening of the ascus, they are also functionally distinct in action; the more frequent non-fissitunicate (or unitunicate) asci have walls which are not made up of functionally distinct layers. At the tip of the asci are frequently found the so called apical structures, which serve as the opening of the asci. An analysis of these structures which are especially recognizable after coloring with iodine, aids in genus determination. Their study requires however a great deal of experience and accurate observation. The tholus, the thickened inner part of the ascus apex, has especial importance. A protrusion of the ascus interior into the tholus in certain respects a trench-like recess of the tholus into the ascus lumen is called “chambre oculaire” or ocular chamber. Within the tholus one can often distinguish a region not or weakly colored with iodine (“axial mass”). A table (page 30) gives illustrations of important ascus forms and apical structures. Spore Spore size and form are very important characteristics. The size is carefully measured with the ocular micrometer (length and breadth). Significant forms: spherical, broadly ellipsoidal (less than twice as wide as long), narrowly ellipsoidal (more than twice as long as wide), elongate, fusiform, peg-like, or needle-form (see illustration on the right p.31). Pycnidia Pycnidia are as a rule spherical to pear shaped receptacles, which commonly are sunken in the thallus and resemble perithecia. In their interior, pycnospores (=pycnidiospores) are segmented off of specialized hyphae and expelled to the outside through a narrow opening (ostiole). The pycnospores are mostly single celled and colorless. They function as asexual reproductive bodies (conidia), in other cases it is very probable that they have a sexual function, as male sex cells (spermatia). In a few species two or three different types of pycnidia are found with various sizes and shapes of pycnospores, 12
which are then described as macro-, meso-, and microconidia; microconidia are always single celled. Pycnidia are usually recognized as very small blackish points on the thallus; in many cases the pycnidia are stalked or are sessile on the thallus as warts. 3.2.5 The Chemistry of Lichens: Determination with the Aid of Color Reactions Many lichens contain well-defined secondary metabolic products, so called lichen substances. These are organic compounds of most variable structure, which for the most part are known only from lichens. Well versed lichenologists can discover them by means of various processes, e.g. thin layer chromatography. A few of these substances are colored (pigments). These pigments are commonly localized in the cortex of the lichen thalli and are responsible for the yellow, yellow-greenish, brown, or red coloring of many species. Most of the lichen substances are colorless; with few exceptions they are localized in the medulla of the lichen thalli. The awareness of lichen substances is of considerable importance, in some for the systematics of lichens, in others even for the determination of species. One part of the lichen substance reacts with the reagents such as calcium hydroxide or sodium hypochlorite to produce a color. Since similar appearing species often have truly varying lichen substances, these color reactions provide worthwhile additional information and a simple determination aid. (Table page 34-36). In practice the smallest possible drops of the reagent is placed upon the site of the lichen thallus to be tested and the reaction ascertained, whether immediate or gradual, commonly occurring within 15 seconds. The reaction of the lichen cortex (i.e. the upper side of the lichen) and of the lichen medulla is often distinct because of differing lichen substances in these thallus parts. Since sometimes interesting diagnostic lichen substances lie in the medulla, it is in these cases important to test the reaction of the medulla. Therefore the medulla must be uncovered in a sufficiently large surface through a section almost parallel to the upper surface. Each must develop his own technique. One can, for example, “clamp” the razor blade at the narrow side between the thumb and index finger, bringing it by the slightest pressure of the finger into a weak concave form and in very small angle section through the upper surface of the lichen. This manipulation and the observation of the reaction is most easily carried out under the binocular scope. The large reagent drop spreads over a large surface. The differentiation of the reaction between lichen cortex and lichen medulla may then be made difficult. In foliose lichens the best section for testing the medulla reaction is from the underside of the lichen, since here an eventual reaction of the lichen upper cortex can be avoided or less bother. For doing the color reactions one transports the reagent e.g. with a pipette or on the tip of a glass rod. Often the bore of commercial pipettes is too large and the droplet adhering to the pipette is too large, so that the reagent spreads out on the lichen over an unnecessarily large surface. It is better to bring a droplet from the pipette to the edge of a razor blade or onto a toothpick, scraping off excess liquid and only then applying it. For testing the reaction one takes a piece of the lichen which will be disposed of later. One avoids the testing of original portions that must be placed in the herbarium. It may be spoiled by dispersion of the drops. In other cases the customary reagent is toxic and easily stains the paper envelop. The clarity of the reaction depends upon the concentration of the lichen substance. In many cases it cannot be clearly determined whether the reaction is positive or negative. This reaction arises, when the reaction of the thallus is questionable or not otherwise specific, as carried out on the upper side of the thallus. In testing for color reaction on dark lichens (e.g. Bryorias) one lays the lichen tested upon a piece of white filterpaper on a slide. Then a few drops of reagent, e.g. P, are dropped upon it: the reagent diffuses into the white paper, so that the color reaction is better recognized than upon the dark lichen. Also when the lichen has the same color as the anticipated color of the reaction or in the case of very weak coloring (e.g. K+ yellowish), it ought to dealt with in the way described (color is often more definite after drying the paper). Contact of the reagents with the skin and with materials of sundry type ought to be avoided. Above all para-Phenylendiamine is very injurious to health and not infrequently causes in the process damage to garments, paper and furniture. Calcium hydroxide and 13
Page 1 and 2: 555 Color photographs 55 Black and
Page 3 and 4: One by one I thank numerous colleag
Page 5 and 6: of metabolism and in metabolic inac
Page 7 and 8: 1.3.2 Extension of Areas Occasional
Page 9 and 10: The lichen species are for the most
Page 11: through a pore, as a rule it is a p
Page 15 and 16: Argopsin - - - orange Arthothelin -
Page 17 and 18: abrasion or a cut is to be recommen
Page 19 and 20: the case of bark habitats, since ba
Page 21 and 22: providing a process for this in the
Page 23 and 24: Alliance: Parmelion perlatae James
Page 25 and 26: near desert region occurring or lac
Page 27 and 28: Greenwich as well as 47°31’ and
Page 29 and 30: axial mass: to be found in the thol
Page 31 and 32: paraphysoid: arising before or duri
Page 33 and 34: Symbols in the Keys: ! refer to ill
Page 35 and 36: lichen thallus are often deformed a
Page 37 and 38: 5* Thallus not with yellow or pale
Page 39 and 40: cyphellae. Lichesteric acid, Protol
Page 41 and 42: 30 Thallus underside consistently f
Page 43 and 44: Rhizines black to brown-black, scat
Page 45 and 46: 27 On dry calcareous soils (dry gra
Page 47 and 48: Hymenium contains small globose to
Page 49 and 50: 2* On wood, rarer on bark . 3 3 Ap.
Page 51 and 52: 26* Sp. colorless 27 27 Sp. 2- to m
Page 53 and 54: 66 Thallus with Trentepohlia algae,
Page 55 and 56: 102* Ap. with margin, nonpruinose,
Page 57 and 58: 2 Thallus with conspicuous pycnidia
Page 59 and 60: places, very thin, KC+/C+ (transien
Page 61 and 62: 14 Soralia dusty gray-green to dark
Page 63 and 64:
±(Squamatic acid). Above all on Co
Page 65 and 66:
Macentina stigonemoides 70* Thallus
Page 67 and 68:
Thallus crustose, thin, usually gra
Page 69 and 70:
larger, thallus not radiate- rosett
Page 71 and 72:
Similar to A. umbilicata (↑), Lec
Page 73 and 74:
Thallus crustose, little differenti
Page 75 and 76:
loose hyphae (arachnoid). Photobion
Page 77 and 78:
own, sometimes (as in A. ciliaris)
Page 79 and 80:
such progressive eutrification of t
Page 81 and 82:
violet. Hym. and Hyp. colorless to
Page 83 and 84:
only rarely fruiting and overlooked
Page 85 and 86:
in the region, yet lacking in regio
Page 87 and 88:
13* Sp. 2 celled, only a few old sp
Page 89 and 90:
forests. (Pruno-Fraxinetum), m.acid
Page 91 and 92:
the remaining indigenous epilithic
Page 93 and 94:
Bellemerea cinereorufescens 20 Thal
Page 95 and 96:
Porpidion tub. - bor-med-mo - r.rar
Page 97 and 98:
25(28) x 2.5-3 µm. Thallus whitish
Page 99 and 100:
8* Epihym. blue-green, olive, olive
Page 101 and 102:
celled. Thallus finely granular to
Page 103 and 104:
Up into the montane zone on dying m
Page 105 and 106:
subneutroph.-r.acidoph., m.photoph.
Page 107 and 108:
Rhizocarpetum alp. - arct-alp - Alp
Page 109 and 110:
Biatora epixanthoidiza (Nyl.) Räs
Page 111 and 112:
(Determination ↑ Hypogymnia) Intr
Page 113 and 114:
anisotomic- dichotomous ( ). Branch
Page 115 and 116:
amplitude of Pseudevernia f. (↑)
Page 117 and 118:
11 On rock dwelling yellow-whitish
Page 119 and 120:
B. leptocline 42* Sp. narrower, 9-1
Page 121 and 122:
surfaces, subneutroph.-neutroph., m
Page 123 and 124:
ornamented (spirally ordered ribs).
Page 125 and 126:
quinone containing yellow to red co
Page 127 and 128:
K-, also partially yellowish-gray t
Page 129 and 130:
cinnabar- to dark red or brownish-r
Page 131 and 132:
31 Thallus yellow to yellow-orange.
Page 133 and 134:
Caloplaca alociza (Massal.) Migula
Page 135 and 136:
smed-mo/alp - v.rare (R); süSch (U
Page 137 and 138:
anombroph., a-/m.nitroph., e.g. in
Page 139 and 140:
thickened above. Asci clavate, Cand
Page 141 and 142:
Caloplacetum sax. -s’mieur-med(mo
Page 143 and 144:
C. rufescens sits on high relief li
Page 145 and 146:
Psoretum - s’mieur-med - v.rare (
Page 147 and 148:
5 µm, often shrunken at the septum
Page 149 and 150:
Usually on lime-rich rocks up into
Page 151 and 152:
(Key includes Cetrelia, Corniculari
Page 153 and 154:
11* Thallus otherwise colored. Ap.
Page 155 and 156:
habitats, like Parmelia stygia (↑
Page 157 and 158:
Stichococcus. Exc. indefinitely dev
Page 159 and 160:
Chaenotheca gracilenta (Ach.) Matts
Page 161 and 162:
10 Usually growing on whitish crust
Page 163 and 164:
anitroph., Char. Chrysotrichetalia
Page 165:
1 Podetia (at least at the base) wi
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Baden-Württemberg - Lichens of Wales

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