LICHENS AND LICHEN. PARASITES

B.A.N.Z. ANTARCTIC RESEARCH EXPEDITION
ARWPSIS Fries.
Argopsk Th. Fr., Nova Acta R. Soc. Sci. Upsal. 111,2,325; 1858.
Type : A. mega.'ospora Th. Fr.
Primary thallus unlmown. Podetia fruticose, branched, erect, more or less terete, the cortex
peeling and carrying the scattered algal co!onies with it ; algae protococcoid, medulla loose, remain-
ing as an arachnoid tomentum, finally disappearing ; chondroid axis dense, of thick-walled, parallel
hyphae ; phyllocladia terete, branched ; cephalodia cerebriform. Apothecia terminal, disc concave
then nearly plane, black, margin prominent ; pseudoamphithecium of cortex and medulla without
algae ; parathecium thin, reaching the margin, hyaline or brownish ; asci cylindric, 1-8-spored ;
ascospores hyaline or slightly brownish, muriform, thin-walled.
This rare genus, apparently confilled to the sub-Antarctic islands of the Australian quadrant,
has been controversial over a long period although comparatively few specimens exist in herbaria.
First included by Taylor in Stereocaulon Argus without microscopic examination of all the plants,
it was segregated as ArgopsG megalospora, a new genus of Usneaceae by Th. Fries when he pre-
pared his monograph of Stereocaulon in 1858 and pointed out that its microscopic characters are
those figured by Hooker f. for Stereocaulon Argus. In 1883, Miiller-Argau, in studying material
brought back by Naumann from Betsy's Cove, Kerguelen, misidentified his material as the same
species previously described from Campbell Island, and thinking Th. Fries' description in error,
renamed what he supposed to be a single species Argqsis Friesiam. The next year he called
attention to the similarity of his sterile material to the sterile Stereocuqdon cyntosum Crombie. I11
1887 he studied the type of Stereocaulon Argus in Taylor's herbarium and recognized that the
Kerguelen material was distinct from A. megalospwa Th. Fr. (Flora, 71, 19; 1888).
Meanwhile, Nylander, C. R. Acad. Sci., 83, 88 ; 18.76, had described Stereocaulon argodes from
Campbell Island, collected by Filhol. In 1888 (Lieh. Nov. Zeland 16) he reduced the portion of
S. Argus Hook. f. & Tayl, which was not A. megalospvra, to gnonymy with S. argodes.
Reinke (Jahrb. f. wiss. Bot. 28, 119-121; 1895) described the anatomy of A. Friesiam
Miill.-Arg., probably based on material collected by the "Gazelle" Expedition in Kerguelen (as
he does not mention its occurrence elsewhere, and figures botryose cephalodia in the habit sketch,
while his figure of the cross section of the cephalodium suggests the cerebriform type.
Zahlbruckner tried to reconcile the literature without a critical study of the material of either
species resulting in misstatements as citing A. mqalospora as occurring only in Kerguelen
(Engler & Prantl, Die nat. Pflanzenfam. I., I*, 147 ; 1907) and reduces S. Argus, S. cymosum and
A. Frieshu to synonymy with A. megalospora (Cat. Lich. Univ., 4, 674-675 ; 1927).
Fortunately the type of Stereocatdon Argus Tayl. and a duplicate of the type collection of
S. cymosum Crombie (originally identified by Taylor as S. pawhale) are present in the Taylor
herbarium, formerly at the Boston Society of Natural History and recently transferred to the
Farlow Herbarium of Harvard University. Some of the plants of the former specimen agree with
Th. Fries' description of Arg@ megalospora the latter specimen with the description of
9. Friesim Miill.-Arg. Both are similar in podetial characters and cephalodia to Stereocaulon
ramulosq~m (Sw.) Ach. (sensu latwre) and it is possible that spezimens may exist in other herbaria,
placed under this name without microscopic examination.
A. megdospora has a hyaline parathecium and hypothecium, asci apparently not more than
2-spored, of which one degenerates early, leaving a single large muriform spore very similar to th0s.e
of Lopadium and Oropogon, remaining hyaline until late, then becoming slightly yellowish brown,
not the deep brown muriform spore of Rl~itocarpm. S. cymosunt has a brownish, allnost
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