Hypoxylon truncatum (Schwein.: Fr.) J. H. Miller

TELEOMORPH | CULTURES AND ANAMORPH | SPECIMENS EXAMINED | NOTES

NOTES

Hypoxylon truncatum, as defined in this study, corresponds to H. annulatum of Ellis and Everhart (1888, 1892), Miller (1928), and Shear (1945), whereas H. annulatum corresponds to their H. marginatum. The differences between H. truncatum and H. annulatum are discussed in NOTES on H. annulatum.

The following collections are from the southern hemisphere, including the type materials of H. subeffusum Speg. (Anales Soc. Ci. Argent. 18: 274. 1884) and H. puiggarii Speg. (Bol. Acad. Nac. Ci. 2: 508. 1889): BRAZIL: Apiahy, 1888, Puiggari 2341, corticated wood (BPI, ISOTYPE of H. puiggarii). MADAGASCAR: La Mandraka, 1981, Gilles, sent by Candoussau as MAD151, bark of Eucalyptus (JDR). PARAGUAY: Santo Tomés, 12.1882, Balansa, B. 3766, corticated wood of Eugenia (BPI, ISOTYPE of H. subeffusum). The stromata of these collections highly resemble those of H. truncatum. However, they have slightly smaller ascospores, 7-8 x 3-4 mm, and are not associated with Quercus. Their status remains unclear for the present.

Two homonyms of Sphaeria truncata Schwein.: Fr. appear in the literature: S. truncata Bolton published in 1789 and S. truncata (Pers.: Fr.) Fr. in 1823 (see Fries, 1823). Sphaeria truncata Bolton is Poronia punctata (L.: Fr.) Fr. (Fries, 1823; Shear, 1945), and, unlike S. truncata Schwein.: Fr., was not accepted in Fries' sanctioning work. Sphaeria truncata (Pers.: Fr.) Fr. bearing the basionym Hysterium truncatum Pers. [º Lophiostoma truncatum (Pers.: Fr.) Sacc.], although sanctioned in Fries' work, is a later resulting homonym of Sphaeria truncata Schwein.: Fr. Therefore, Sphaeria truncata (Pers.: Fr.) Fr. should be rejected according to ICBN Art. 55.

Shear (1945) considered S. truncata Schwein.: Fr. to be Rosellinia corticium (Fr.: Fr.) De Not. based on his observation of a specimen at UPS sent to Fries by Schweinitz and on the fact that both Fries (1823) and Schweinitz (1832) systematically placed S. truncata [as S. truncatula Schwein. in Schweinitz (1832)] in Fries' section Byssisedae of Sphaeria where a number of current Rosellinia were disposed. Miller (1961) argued with Shear's reasoning due to the fact that Schweinitz (1922) clearly described S. truncata Schwein.: Fr. with stromata "apice truncata marginata", and stressed that "this would not apply to the Rosellinia". We have examined two packets of autographed specimens of Schweinitz from PH related to the problem of S. truncata Schwein.: Fr. One packet [U.S.A.: Pennsylvania, Bethlehem, Syn. 1598] contains material attached on a paper card and labeled as "Sphaeria truncata Fr.", and wrapped material labeled as "Sphaeria truncata L.v.S. & Fr.". The former is a Lophiostoma taxon, whereas the latter is a good H. truncatum. This packet apparently is not the original collection from North Carolina on which the description of S. truncata is based. Schweinitz (1832) intended to refer Syn. 1598 to Fries' Sphaeria no. 357 in Fries (1823) where one finds S. truncata (Pers.: Fr.) Fr. Apparently, Schweinitz deliberately changed his S. truncata Schwein.: Fr. to S. truncatula Schwein. due to the existence of S. truncata (Pers.: Fr.) Fr. Hence, Sphaeria truncatula Schwein. should be considered a nomenclatural synonym of Sphaeria truncata Schwein.: Fr. and rejected. The inclusion of the H. truncatum in the packet Syn. 1598 is simply a mistake. The other packet, Syn. 1501, labeled by Schweinitz as S. truncatula Schwein. also contains materials attached to a paper card and material enclosed in an envelope. The specimen enclosed in the envelope is a tiny piece of H. truncatum. Those specimens attached to the paper card are composed of two heterogeneous components: the lower piece is Rosellinia corticium, whereas the upper piece is H. truncatum. This packet Syn. 1501 probably represents the original material of S. truncata, and was relabeled as S. truncatula by Schweinitz. Schweinitz (1822) described S. truncata with stromata "primo bysso involuta; demum aterrima, nitens, dolioli forma, apice truncata, margine annulata". It is obvious that Schweinitz (1822) integrated characteristics of these two fungi into the protologue of S. truncata. He described the subiculum from the Rosellinia part which he believed to be the young stromata and the ostiolar truncation from the Hypoxylon part which he believed to be the mature stromata. When Schweinitz sent a duplicate of this collection to Fries, he only enclosed the Rosellinia part [North America, Schweinitz, L.D.V., corticated wood (UPS 57638)], and labeled it as "Sphaeria truncatula Schwein." Since the usage of S. truncata Schwein.: Fr. has widely been accepted as a Hypoxylon rather than a Rosellinia, it is unwise to accept Shear's suggestion in considering S. truncata Schwein.: Fr. as a synonym of R. corticium. We thus designate the upper piece on the paper card in packet Syn. 1501 at PH as the lectotype of S. truncata Schwein.: Fr. The Rosellinia part in packet Syn. 1501 at PH and its duplicate at UPS should be ignored.

Interestingly, while Schweinitz (1832) replaced S. truncata Schwein.: Fr. with S. truncatula Schwein., Fries (1832) coincidentally replaced S. truncata (Pers.: Fr.) Fr. with S. truncatula Fr.: Fr. in the Index of Systema.

As explained in NOTES on H. annulatum, Fries (1828) probably described Sphaeria annulata var. depressa Fr.: Fr. based on an element mixed with the type of S. annulata Schwein.: Fr. at UPS which was marked as "A" by Starback. Here we accept the piece corresponding to the part marked by "X" in Fig. 3 in Shear (1945) as the lectotype of S. annulata var. depressa.

Deighton (1985) considered the anamorph of H. truncatum to be Nodulisporium puniceum (Cooke & Ellis) Deighton [º Verticillium puniceum Cooke & Ellis]. His description could fit either H. truncatum or H. annulatum, considered synonymous by Deighton (1985), but considered as distinct species here.