A CONSPECTUS OF THE LICHEN GENUS STEREOCAULON ...

I. MACKENZIE LAMB: A Conspectus of Stereocaulon 257
57. Stereocaulon virgatum ACH.
ex SPRENG. Caroli Linnaei . . . Systema Vegetabilium, Editio Decima Sexta, 4 (1): 275 (1827); MULL.
ARG. Flora, 70: 286 (1887); VAIN. Ann. Acad. Sci. Fenn. ser. A, 6 (7): 26 (1915).
Typus: Leeward Islands, Guadeloupe, leg. ?, date ? (H-ACH, holotypus).
Facultative synonyms: Stereocaulon virgatum f. achariana VAIN. J. Bot. 34: 34 (1896). - Stereocaulon
virgatum f. applanata VAIN. loc. cit. - Stereocaulon virgatum f. primaria VAIN. loc. cit. - Stereocaulon
giltayi DUVIGN. Biol. Jaarb. "Dodonaea", 9: 87 (1942). - Stereocaulon sphaerophoroides TUCK.
An Enumeration of North American Lichenes: 52, footnote (1845) (non auctt. plur.).
Exsicc.: Lich. Exs. Univ. Colorado Mus. Fasc. IX (1971) no. 337 (LD).
Icon.: DUVIGN. 1942, fig. 3A, B, as St. giltayi.
Mat. chim. : atranorin, stictic acid and norstictic acid, the latter two substances occurring
in varied concentration, either in approximately equal proportions or with one or other of
them strongly preponderant or perhaps in some cases present to the total exclusion of the
other. The macroscopic reactions are therefore variable: K+yellow then red, PD+yellow
(norstictic acid predominating) or K+yellow, PD+orange-red (stictic acid predominating).
VAINIO'S 2 forms achariana and primaria were distinguished on the basis of such different
reactions.
Distrib.: West Indies (Greater Antilles, Leeward Islands, Windward Islands) and Central America
(Nicaragua). A specimen said to be from Venezuela, but with this origin queried by TH. FRIES, leg.
FUNCK and SCHLIM (date ?) is present in UPS-TH FR. St. giltayi DUVIGN. was described as from Scotland,
certainly as the result of an error.
Remarks: St. virgatum is closely related to St. scutelligerum TH. FR., and like the latter
is usually destitute of cephalodia. Cephalodia have however been seen in a few specimens
from Dominica and Guadeloupe. They are of the anatomically undifferentiated, "spherical"
to "botryose" type normally associated with species of the section Denudata. TH. FRIES
(1857, 1858) and NYLANDER (1860) erroneously stated that St. virgatum is a synonym of
St. furcatum FR. The latter is referable to St. ramulosum (Sw.) RAusc~., as was pointed out
by MULLER ARG. (1887), and confirmed by RIDDLE (ex DODGE, 1929) and by the present
author. Stereocaulon sphaerophoroides TUCK., the commonly used name for a species endemic
to the Azores, Madeira and Canary Islands, is a synonym of St. virgatum; see discussion on
p. 206.
58. Stereocaulon vulcani (BORY) ACH.
Lichenographia Universalis: 583 (1810). - Lichen vulcani BORY, Voyage dans les Quatre Principales
Iles des Mers d'Afrique, 3: 147 (1804). - Stereocaulon denudatum var. vulcani (BORY) NYL. Synopsis
Methodica Lichenum, 1 (2): 248 (1860).
Typus: R6union Island (Borbonia), no exact locality given, leg. BORY DE SAINT-VINCENT (date ?).
There are several mounts in PC-HUE (ex herb. RICHARD) which qualify as type material44. As lectotype
we have selected the best of these (herb. HUE no. 257 pr. p.), labelled "Herb. Richard Stereocaulon
Vulcani Ile de Bourbon. Bory" (lectotypus, lectotypif. nov.).
Facultative synonyms: Stereocaulon flavireagens GYELN. Ann. Cryptog. Exot. 4: 173 (1931). -
Stereocaulonflavireagens f. cinerascens MAGN. ex MAGN. et ZAHLBR. Ark. Bot. 31A (6): 43 (1944). -
Stereocaulonflavireagens f. densum MAGN. op. cit. p. 42.
Exsicc.:" ABB. Lich. Madagasc. et. Borbon. Sel. Exs. Fasc. I1 (1966) no. 38 (Ch. str. I) (FH). -
HEPP, Flechten Europas Band I, Heft 1 (1853) no. 2 pr. min. p., as St. denudatum B. vesuvianum (Ch. str.
44 DODGE (1929, p. 119) erroneously states the type of Lichen vulcani to be from Mauritius.
46 V~ZDA, Lich. Sel. Exs. no. 415, as St.flavireagens, is not this species, but St. rubiginosum PERS.