Bull. Natl. Mus. Nat. Sci., Ser. B, 40(2), pp. 69–72, May 22, 2014

Usnea ﬂavocardia (Parmeliaceae, lichenized Ascomycota) New to Asia
Yoshihito Ohmura
Department of Botany, National Museum of Nature and Science,
Amakubo 4–1–1, Tsukuba, Ibaraki 305–0005, Japan
E-mail: ohmura-y@kahaku.go.jp(Received 14 February 2014; accepted 26 March 2014)

Abstract Usnea ﬂavocardia is reported as new to Asia. It was collected from Taiwan where it
grows on twig of Aquifoliaceae and bark of Tsuga sp. at elevation between 1900 and 3100 m. The
description is given based on the Taiwanese specimens.
Key words : ﬂora, lichenized fungi, secondary substances, Taiwan, taxonomy.

The genus Usnea (Parmeliaceae, Ascomycota)consists of more than 300 species, and is widelydistributed from polar zones to tropical area
(Kirk et al., 2008). Diagnostic features of thegenus include a fruticose thallus with a cortex,
medulla, and a cartilaginous central axis, and thepresence of usnic acid in the cortex.
During the course of ﬂoristic study of lichensin Taiwan, an interesting Usnea species, which
has not been reported from Asia so far, wasfound after the taxonomic examinations of collected specimens.
The purpose of this study is to provide adescription based on the Taiwanese materials andto discuss the morphology and chemistry.

the branch were measured following the methodof Clerc (1984a). The mean (italic), standard
deviation and extreme values (in parenthesis) ofthe ratios are shown in the description. Cross
sections of thallus were cut by hand with a razor
blade, and observed after mounting in GAW(glycerin : ethanol : water, 1 : 1 : 1).
Lichen substances were examined using thinlayer chromatography (TLC) (Culberson andKristinsson, 1970). Solvent B system (hexane :methyl tert.-butyl ether : formic acid, 140 : 72 : 18)(Culberson and Johnson, 1982) was used for theTLC analysis. Iodine test (I) was performed on
an axial section with 0.5% Lugolʼs iodine solution.

Materials and Methods

Results and Discussion

Field investigations in Taiwan were carried out
by the author between 2008 and 2011, and ca.
300 specimens of Usnea were collected. This
study is based on those specimens which arehoused in the National Museum of Nature andScience (TNS), Tsukuba, Japan.
Morphological observations were made using
a dissecting microscope and a bright ﬁeld microscope. The diameter of branch was measured
using a well-developed thicker branch. The ratiosof thickness of the cortex, medulla, and axis forUsnea ﬂavocardia Räsänen, Revista Universitaria (Santiago) 21(1): 139, 1936.
Type: CHILE. Valdivia: Corral, sobre cercos,
1929, Gunckel 1635 (holotype H, not seen).
%C/%M/%A: 4.5/32.5/26 (Clerc, 2004). Chemistry: usnic, norstictic and connorstictic acids,
traces of unidentiﬁed triterpenoids (Truong et al.,2011).
＝Usnea quercina Bysrek & Gorzynska, U.
wirthii P. Clerc (Clerc, 2004).
Thallus fruticose, shrubby, erect, up to 3.5 cm

70

Yoshihito Ohmura

Fig. 1. Morphology of Usnea ﬂavocardia (A–D: Y. Ohmura 7008, TNS; E–G: Y. Ohmura 8636A, TNS).
A. Erect thallus with anisotomic-dichotomous branching. B. Base of thallus and constricted base of lateralbranches. C. Concave soralia with granular soredia, which is larger than the branch diameter. D. Inﬂatedbranch with a yellow axis and two-layered medulla. E. Red spots on the cortex. F. Red pigmentation at thetips of papillae. G. Ceratina-type cortex with secretion of red pigment into the cell walls around the lumina ofcortical hyphae. Scales: A, B, D＝1 mm; C, E, F＝0.5 mm; G＝20 μm.

long, grayish green with or without scattered redspots, concolor to brownish black at the base;branching anisotomic-dichotomous; branches
matt to slightly glossy on the surface, lacking
pseudocyphellae and maculae, with or without
foveoles, terete, inﬂated, gradually tapering, withmany ﬁbrils and lateral branches, 1.0–1.1 mm indiameter; lateral branches slightly to distinctly
constricted at the base; papillae sparse to numerous, verrucose to cylindrical; soralia common,formed mainly on lateral branches, developed
from the top of eroded papillae or cortex, moreor less discrete, rounded in shape or conﬂuent
each other to form irregular mass of asexual
propagules, larger than branch diameter, sessile
to slightly stipitate, cortical margin reﬂexed asgrowing, concave to slightly convex at the top
with granular soredia and occasionally with isidiomorphs. Cortex thin, (6.4)-6.3-7.8-9.2-(9.7)%of the radius (n＝4), ceratina-type plectenchy-

Usnea ﬂavocardia New to Asia
matous (see Ohmura, 2001); hyphae pachydermatous, secreting red pigment in the cell wall inpart or no pigment, with oblong or turbinate
lumina. Medulla lax in totality and compact justunder the cortex, wide, (27)-27-29-31-(31)% ofthe radius (n＝4), white but yellow around theaxis. Axis solid, thin, (22)-22-26-30-(32)% of thediameter (n＝4), yellow to pale orange especiallyon the surface, I–. Apothecia not seen.
Chemistry. Usnic, psoromic and 2′-O-demethylpsoromic acids.
The diagnostic features of U. ﬂavocardia inthe material collected in Taiwan are (1) the erect
thallus with anisotomic-dichotomous branching(Fig. 1A), (2) the concolor to brownish blackbase (Fig. 1B), (3) the inﬂated branches withconstricted at the attachment point (Figs. 1B,1D), (4) the medulla which is lax in totality andcompact just under the cortex (two-layeredmedulla) (Fig. 1D), (5) the concave to slightlyconvex soralia with granular soredia, which arelarger than branch diameter and the cortex margin reﬂexed as growing (Fig. 1C), (6) the yellow
colored axis (Fig. 1D), (7) the red spots on thecortex or papillae when present, (Figs. 1E–G),and (8) the presence of psoromic acid as a major
substance.
Six chemotypes have been known in this species: chemotype 1, usnic, psoromic and±salazinic
acids, and±unidentiﬁed triterpenoids; chemotype 2, usnic, stictic and±norstictic acids; chemotype 3, usnic, norstictic and±connorstictic
acids, and±unidentiﬁed triterpenoids; chemotype 4, usnic, salazinic and±norstictic acids;
chemotype 5, fatty acids; and chemotype 6, nodetectible substance by TLC (Clerc, 1984b,2004, 2007; Clerc and Diederich, 1991; Halonen
et al., 1998; Truong et al., 2011). The chemotype
1 (psoromic acid) is common in Europe but also
randomly distributed in North America, andother chemotypes were found outside of Europe(Clerc, 1997; Tavares et al., 1998). All Taiwanese
specimens belong to the chemotype 1.
The red pigment in U. ﬂavocardia is secreted
into the cell walls around the lumina of cortical
hyphae. This pigmentation mode is similar to71

those of U. rubicunda Stirt. and U. rubrotincta
Stirt. (Ohmura, 2001). However, the red pigmentation in U. ﬂavocardia is more localized as spots
scattered in the cortex or in the tips of papillae.
In addition, the red color in U. ﬂavocardia is usually darker than those of U. rubicunda orU. rubrotincta as Tavares et al. (1998) also
pointed out. The red pigmentation in the fourthalli collected from Taiwan varies very much:absent, rare, common as spots on the cortex (Fig.
1E), or commonly localized in the tips of papillae (Fig. 1F) were observed.
Halonen et al. (1998) mentioned the occurrence of distinct segments at the branches in thematerials from British Columbia, which is a
result of annular cracks that often are lined bywhite medullary rings. But such feature was notclearly observed in the Taiwanese materials.
The two-layered medulla, i.e. compact outerlayer and lax inner layer, is known as one of thefeature for this species (Tavares et al., 1998;Clerc, 2007). That is, the compact outer layer justunder the cortex is composed of conglutinatedmedullary hyphae, and the inner layer is lax withusual medullary hyphae. The layer of conglutinated medullary hyphae has been sometimes
considered as a component of “two-layered cortex” as reported in U. thomsonii Stirt. (Asahina,1955; Awasthi, 1986). Hyphae of medulla in thegenus Usnea can be conglutinated to form bundles, lumps, or a layer, especially near the algal
layer (Ohmura, 2001). Therefore, the term “twolayered medulla” might be better to use than“two-layered cortex”.
Usnea ﬂavocardia resembles small size ofU. glabrata (Ach.) Vain. in the morphology.
However, it is distinguished from the latter by
the yellow axis and the presence of psoromic
acid. In addition, the occurrence of red spots inthe cortex or papillae, when present, is also goodcharacter to distinguish the species.
This species has been known from Europe,
North America, South America, Macaronesia(Clerc, 2007), and the distribution is now
extended to Asia. It was found on twig of tree
(Aquifoliaceae) or bark of Tsuga sp. growing72

Yoshihito Ohmura

together with U. pygmoidea (Asahina) Y.
Ohmura or U. wasmuthii Räsänen at elevation
between 1900–3100 m in Taiwan. The total number of taxa in the genus Usnea in Taiwan is now
40 species and one variety (Ohmura, 2012).
Specimens examined. TAIWAN. Yilan Co.:
Lake Cueifong, Mt. Taiping, Nan-ao Township(N24°30′, E121°36′), on twig of Aquifoliaceae,
ca. 1900 m elev., 30 September 2011, Y. Ohmura
8636A. Nantou Co.: en route from Chengkung
No. 2, 3 Cabin to North Peak of Mt. Chilai, Mt.
Chilai, Taroko National Park (N24°06′50.0″,E121°19′19.3″), on bark of Tsuga sp., ca. 3100 melev., 30 September 2009, Y. Ohmura 7008.
Acknowledgments
I wish to express my gratitude to S.-H. Lin,J.-D. Yang, K.-Y. Yao, E.-L. Chu, S.-C. Chen,T.-Y. Hsiao, Z.-Y. Zheng, Y.-W. Chen, Y.-C.
Chen, and M.-H. Kao for their kind arrangements
and helps of ﬁeld excursions in Taiwan; an anonymous reviewer for the critical reading of thismanuscript. This study was partly supported byJSPS KAKENHI Grant no. 24300314.
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