Typification and Identity of Adiantum tetragonum (Pteridaceae)

2005·2.4 MB·English

by  Jefferson Prado

MISSOURI
BOTANICAL
American Fern NOV
Journal 95(3):89-93 (2005)
2
9
2005
GARDEN
LIBRARY
and
Typification Identity of
Adiantum
tetragonum
(Pteridaceae)
Prado
Jefferson
Instituto de Botanica, Caixa Postal 4005, 01061-970, Sao Paulo, Brazil
Michael Sundue
A.
New
of Systematic Botany, The York Botanical Garden,
Institute
NY
Bronx, 10458-5126, U.S.A.
—
Abstract. Adiantum tetragonum Schrad., a rare and endemic species to Brazil, typified.
is
Introduction
Adiantum represented by ca 64 species in Brazil. Several recent studies
is
new endemic &
have revealed taxa and/or species to Brazil (Prado Palacios-
&
Rios, 1998; Prado, 2000; Prado, 2001; Lellinger Prado, 2001; Prado, 2003;
Sundue & Prado, 2005). This paper a contribution toward a revision of
is
Adiantum Adiantum tetragonum and
Schrad., a rare
in Brazil. treats
It
We
endemic species that has not been collected or recorded in 180 years.
modern and
provide description lectotypification of this species to bring to
a
it
community.
the attention of the botanical
Adiantum tetragonum Schrad., Got. Gel. Anz. 87: 872. 1824. Lectotype (here
Almada
designated): BRAZIL. Bahia: "Habitat in sylvis inter et Ferradas,"
Maximilianus Neovidensis photos BM!,
prov. Bahiae, Pric. s.n. (BR!,
s.d.,
&
SP!). Figs. 1 2.
x
Rhizomes short-creeping, the scales 1.0-2.0 0.2-0.4
Plants scaly,
terrestrial.
mm,
castaneous, shiny, the bases truncate, the apices attenuate,
lanceate,
X
margins Fronds 60 30 cm, closely spaced along the
the entire. ca.
filiform,
mm
rhizomes. Stipes 0.3 wide, ca. the length of the fronds, castaneous,
Vi
Axes 2-4 castaneous
lustrous, glabrous or sparsely puberlent. bifurcating times,
mm
orange-brown, lustrous, the adaxial surfaces puberlent, the hairs 0.1
to
brown Laminae
curved, hyaline. chartaceous, 3-5-pinnate, the
long, light to
ultimate segments 6-10 X 2.5-4.0 cm, essentially conform, narrowly deltate to
the color of the segment stipes passing onto the bases of the
lanceolate, stipitate,
segment
segments, the segment bases asymmetric, truncate to obtuse, the apices
segments sometimes with
gradually tapered slightly attenuate, the basal
to
cm
margins segments
a basiscopic lobe, the lobes ca. 2 long, acute, the of sterile
margins segments shallowly lobed, the lobes truncate,
crenate, the of fertile
each lobe bearing a single sorus; abaxial lamina surfaces glabrous; adaxial
lamina
surfaces puberlent along the costae. Veins forked, with
free, a central
mm
vein forming an
excurrent costa in each segment. Sori 3-8 long, 6-12 along
each margin
of the segment,
linear or slightly arcuate, the indusia brown,
glabrous, the margins
of the indusia Spores not
entire. seen.
Aditional Material Examined.—BRAZIL.
Bahia:
Caatiba; entrada para cidade
a
km
de km
ca. 11 Itapetinga, rod. para Caatiba 31.2 da BR-415,
14°59'48"S
PRADG TETRAGONUM
SUNUl
& W
\\ 11 \1
'!
>!
I
92 AMERICAN FERN JOURNAL: VOLUME NUM1
95
40°23'12" W, March
11 2000, G. Jardim 3153 (CEPEC, NY). Minas
et
al.
/.
Gerais: "Patria Brasilia, Capitania Minas Geraes, circa Aldea dos Maxacalis,
Pohl 3263"
photo
(BR!,
SP!).
Endemic
Distribution.— to the dry Atlantic forests of Bahia State, and inland
from Minas
forests Gerais growing between 200 and 500 m.
State,
Adiantum
tetragonum was by
described Schrader
(1824) in a rather
unexpected
place, in the publication of a lecture that he delivered on
nd
November
22 1823 memorial
at the celebration of the Royal Society in
,
Gottingen (Zimmer & Prado No was
1997). type material cited in the
protologue; however, we know new
that species described by Schrader
all
were based on
(1824) material collected by Maximilianus Neovidensis
Princ.
Two
Bahia
in
State, Brazil. authentic specimens tetragonum
(isosyntypes) of A.
BR
were found by
at the senior author. Original labels retained on these
specimens
confirm One
their authenticity. of these two sheets, has a label of
Herbarium
Martius'
in the lower left corner of the sheet, and selected here
is
as the lectotype of Adiantum tetragonum. This
sheet contains part of a
fertile
On
frond without
a rhizome. the same bottom
sheet, in the right corner, there
is
BR
another with
label a imprint that bears the determination. This specimen
was
by
illustrated Martius and
(1834, 63) reproduced here Another
is (Fig.
t. 1).
specimen, Pohl was
3263, Minas
collected in Gerais but there no
State,
is
evidence was examined
that by Schrader propose
it to A. tetragonum.
After Schrader's Adiantum
publication, tetragonum was
treated as a distinct
by
species Martius
(1834), Presl (1836), Hooker and Baker
(1851), (1870).
Whereas
Martius
(1834) presented an
illustration of this species, these other
authors recognized
this species based upon
solely the
original description.
Hooker
commented: "No my
(1851) specimen come
has ever under
observation, nor
that of Mr. Smith; nor has any
botanist noticed besides
J. it,
Schrader and
Martius".
Until the recent collection by Jardim was
G. et brought our
al. to attention,
J.
Adiantum
tetragonum was known
only from
the type collection. Roughly 180
years have passed was
since
last collected.
it
Adiantum
tetragonum
is distinguished by chartaceous and decompound
its
laminae,
large lanceolate narrowly
to deltate pinnules, and
free veins, linear
Adiantum
tetragonum most
sori. similar A. mynssenae
is to Prado, A.
abscissum and
Schrad., A. curvatum These
Kaulf. taxa have repeatedly
all
mm
and
bifurcating adaxially puberlent axes, provided with
0.1-0.2 long
hairs,
the color of the stipes passing onto the segment bases, laminae
that lack
venuloid
idioblasts, veins that are forking, free and not anastomosing, and
Adiantum
multiple linear sori. abscissum and A. curvatum can be
distin-
guished from A. tetragonum because these taxa have scales present among the
along
hairs their axes.
Adiantum
mynssenae
can be distinguished from A. tetragonum by the former
having
non-costate, dimidiate, trapeziform segments compared
the
to costate,
laceoalate or narrowly deltate segments of A. tetragonum. Adiantum
adian-
toides and its close relatives discussed in Sundue and Prado (2005) also share
PRADO AM)
& SUNDUE: TYPIFICATION )\'UM 93
<
I
several of the characters that unite A. tetragonum, A. mynssenae, A. abscissum,
and A. curvatum. All of these taxa have adaxially puberlent axes, provided with
mm
0.1-0.2 long hairs, the color of the stipes passing onto the segment bases,
laminae that lack venuloid idioblasts, and multiple linear sori per segment,
but the group of A. adiantoides differs by having anastomosing veins.
Adiantum
tetragonum could also be confused with species with similarly
shaped segments, such as A. subcordatum Sw. or A. polyphyllum Willd., but
those species differ by having glabrous axes, and the color of the segment
stipes stopping abruptly the segment bases.
at
We
thank the Curators of tudied NY, and the LuEsther
th. at
I
New
T. Mertz Library of the York Botanical Garden for permission to reproduce the Martius plate.
CNPq
The number
senior author thanks for financial support for this project (Proc. 300843/93-3).
Literature Cited
Hooker, W. 1851. Species Filicum, Willian Pamplin, London.
vol. 2.
J.
Lellinger, D. B. and Prado. 2001. The group of Adiantum gracile in Brazil and environs. Amer.
J.
Martius, C. F. von. 1834. Icones plantarum cryptogamicarum quas in intinere annis MDCCCXVII-
MDCCCXX
per Brasiliam. Monachii.
A
new Adiantum
Prado, 2000. species of (Pteridaceae) from Bahia, Brazil. Brittonia 52:210-212.
J.
new
Prado. 2001. Adiantum giganteum (Pteridaceae), a maidenhair fern from Amazonia, Brazil.
|.
New
Prado, 2003. species in Adiantum from Brazil. Amer. Fern 93:76-80.
J. J.
and M. Taxonomy and Adiantum and
Prado, Palacios-Rios, 1998. distribution of trapeziforme
J.
A. pentadactylon. Amer. Fern 88:145-149.
J.
1836
Presl, C. B. iiae. Pragae.
i
Schrader, H. A. 1824. Illustratio Filicum a Serenissimo Principe Neowidensi in Brasilia
hujus familiae structura oeconomia.
e et
and Prado. 2005. Adiantum diphyllum, a rare and endemic species to Bahia State,
l.
J.
name Adiantum
the dissimile (Polypodiaceae,
t