Public Description of Clavaria fragilis Holmsk.

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Name: Clavaria fragilis Holmsk.
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General Description:

Clavaria fragilis Holmsk. : Fr.; Beata ruris 1:7, 1790; Syst. Mycol. 1:484, 1821.
Lectotypus: Holmsk., Beata ruris 1:pl. 2, 1790; designated here.
Epitypus: Slovakia. Nízke Tatry Mountains, Malužiná village, Michalovo valley, 48°59′55.6″N, 19°45′6.67″E, 760 m. Pasture, 1 Sep 2007, I. Kautmanová (BRA CR-9726); designated here.

Basidiomata in dense clusters, 30-100 mm high, unbranched, fusiform, round or ellipsoid in cross section, mature tips often longitudinally constricted, not flattened, tips in maturity acute or subacute, upper fertile part 1-7 mm thick, sterile base 1-2 mm thick and usually distinct, more reflective than hymenium and approx. one-third the total height, pale yellowish white to pale yellowish gray (3A2-4A2-4B2), at base slightly darker (4B3), often turns pastel yellow (2A4) upward or completely (possibly because of infection by bacteria) or tips becoming oak brown (5D6) with age or drying, surface smooth but becoming rough when old. Flesh fragile without odor. Macrochemical reaction: hymenium negative in ferric salt (FeCl3).

Spores (4.6-)4.8-6.2(-6.4) x (3-)3.1-3.9(-4) µm (av. 5.5 × 3.4 µm), Q = (1.39-)1.41-1.77(-1.8) (av. Q = 1.6), pyriform, with 0.5-0.7 µm long hilar appendage, surface smooth under light and SEM microscope (Fig. 3). Basidia (32-)33-43(-45) x 6-9 µm, without clamps, mostly tetrasporic. Hymenium distinctly thickening. Subhymenium approx. 30-50 µm thick, composed of approx. 2-3 µm thick, interwoven, short cells that are sharply delimited from trama. Trama composed of parallel hyphae with 20-100 × 5-20 µm large cells that are frequently secondarily septate. Surface of sterile base covered by repent hyphae with terminal cells scattered, 15.5-28 × 3-5 µm, cylindrical or clavate. Clamp connections absent in all tissues.

Literature :
Kautmanová, I.; Adamčík, S.; Lizoň, P.; Jančovičová, S. 2012. Revision of taxonomic concept and systematic position of some Clavariaceae species. Mycologia. 104(2):521-539

Page number : 525
Remarks (internal) : Typification.
In the protolog of C. fragilis Holmskjold referred to previously published illustrations, but he provided the description also with his own plate (Holmskjold 1790, pl. 2). The Holmskjold’s plate is selected as the lectotype here. To select the epitype we compared spore values of material collected from the neighboring countries of Denmark, the type locality of C. fragilis (Holmskjold 1790). Collections from Norway have narrow and long spores with highest Q value. Collections from Germany in contrast are the shortest. Corner (1950) estimated an average value for European collections of 1.6 and he treated shorter spores (with average 1.43) as var. gracilis. Also other studies (e.g. Jülich 1984) agreed instead with spores longer than 5 µm; therefore we selected an epitype with values closer to Norwegian collections rather than to German ones. The high amount of variation in spore size and LSU sequences suggests that this appears to be a species complex rather than one hypervariable species. There is a little congruence visible in our phylogenetic tree (Fig. 1, SUPPLEMENTARY TABLE I), the epitype and other collection (SAV F1262) with intermediate Q value of spores has relatively similar LSU sequences and the collection with longer and narrower spores ( BRA CR9727) is different but more similar to them than those with short spores (BRA CR9725). Variation in spore size and form of basidiomata often has been treated as infraspecific taxa (see discussion on the species in Appendix I). Our description above is based on type specimen and other collections with similar Q value and other morphological characters.

Description author: Erlon Bailey (Request Authorship Credit)