Table Of Contentan Unusual
Gentianella weigendii (Gentianaceae),
New
Gentian from Peru
Volume Number
22, Pringle
1
2012 Gentianella (Gentianaceae) from Peru
Habitat and phenology. Gentianella weigendii northern Ancash Department, seems likely that
is it its
known
only from the type collection. It was found in total geographic range is not extensive, although
well-developed jalca vegetation, among numerous according to Maximilian Weigend (pers. comm., 23
m
shrubs and perennial herbs, 4000 Weigend June 2009), Gentianella weigendii was locally
at et
(
common
The March
al. 5083, in sched.). date of this collection at the type locality.
on
provides the only information available
its
named
Etymology. Gentianella weigendii for
is
Maximilian Weigend, of the Institut fur Biologie-
IUCN
Red List category. Data are deficient for Systematische Botanik und Pflanzengeographie-der
recommended listing (DD) (IUCN, 2001). With the Freien Universitat der Berlin, who collected the type
species being known only from a single locality in specimen and thought that represented a new
it
Volume Number
22, Pringle
1
2012 Gentianella (Gentianaceae) from Peru
coralline trichomes are absent; the corollas are green August Weberbauer, as well as herbarium specimens.
and scarcely longer than the calyces; and the corolla If Weberbauer’s botanizing had extended to the range
The
lobes are ovate-triangular, shorter than the tube. of Gentianella weigendii, might be that Gilg’s
it
flowers of G. weigendii and G. thyrsoidea are similar description of the nectaries of Pitygentias was based
in aspect, but in G. thyrsoidea the filaments are on alcohol-preserved flowers of G. weigendii, whereas
equal, 5-8 mm, inserted the same level about the herbarium specimens that he identified as P.
all at
10-60X
0.5X the height of the corolla tube. At pinifolia and P. thyrsoidea, and earlier as Gentiana
magnification I detected no floral glands in G. tupa, represented Gentianella thyrsoidea. The name
thyrsoidea Weigend 5125 and 7712, HAM), Gentiana tupa was based on plants from Diezmo,
et al.
(
SEM A
BC
but observations with fresh material and with Peru. Ruiz and Pavon specimen from Diezmo
at
would be desirable. (according to Ibanez, 2006), and a Ruiz and Pavon
F MA)
and (now and by
Vegetatively, Gentianella weigendii thyrso- collection divided, interpreted
G.
0.2- and Macbride an
idea differ distinctly. Plants of G. thyrsoidea are Fabris (1958) (1959) as isotype of
3-6 name
3.5 dm; those of G. weigendii are dm. In G. the Gentiana pinifolia, were both designated by
thrysoidea the basal and near-basal leaves are very the same unpublished name by Ruiz and Pavon in
numerous, often over 100, and the cauline leaves are herb., and both were annotated as P. pinifolia by
closely spaced the entire length of the stem (distal Gilg. These specimens are probably from a single
intemodes commonly 2-8 mm, occasionally to 15 collection, of which identified a component as
I
mm
mm, 40 on The The basionym
rarely to the tallest plants). leaves Gentianella thyrsoidea. type of the
BM)
are ascending and distally incurved, and in combi- Gentiana thyrsoidea Hook. Cruikshanks s.n.,
(
name
nation with the closely spaced axillary cymules, often likewise represents the species to which the
much
conceal of the stem. All of the leaves are Gentianella thyrsoidea currently applied.
is
Although weigendu
the similarities of Gentianella
of the abruptly expanded portion just above the basal to G. thyrsoidea and G. weberbaueri have been noted
sheath, reminding Ruiz and Pavon of pine needles (as above, evidence, morphological or molecular,
little
indicated by the old epithet pinifolia The leaves are exists to indicate the phylogenetic relationships
).
about eight per whorl the mid-cauline nodes, more among the South American species of Gentianella
at
numerous at the proximal nodes, with the bases or between the South American species and those of
mm
8-12
which on
united into a sheath, is the larger other continents. Divisions of Gentianella (historical-
The
plants. entire plant above ground forms a dense ly included in Gentiana into sections have included
)
2-6 cm
cylinder in diam. In weigendii the basal species, or except magellanica (Gaudich.)
G. all all G.
X
leaves are fewer and wider, 7-12 cm 4-13 mm; the Fabris ex D. M. Moore, in a single section, and
X
cm
distal cauline leaves are lance-triangular, 2.5-7 divisions of Gentianella into segregate genera
7-13 mm;
and the leaves are not expanded near the subsequent to Gilg’s recognition of Pitygentias have
not discussed South American species. Some char-
much
and the leaves spread widely, so that of the acter states occur in diverse combinations rather than
stem visible. The cauline leaves are in whorls of consistently occurring in syndromes, suggesting the
is
four, separate to the base. frequent occurrence of homeoplasy. Molecular phy-
From which have
Gilg’s description of Pitygentias Gilg, logenetic studies indicated that Gentianella,
he segregated from South American Gentiana in
s.l.
&
1916, might be suspected that Gentianella with paired nectaries, monophyletic (Hagen
it is
weigendii had already been described, but no earlier Kadereit, 2001), but few South American species
specific epithet is available for this species. Gilg have been included in such studies to date.
treated Pitygentias as comprising two species, both of Weigend Weigend 5083, in sched.)
et al. et al.
(
now
which are included in Gentianella thyrsoidea suggested that the flowers of Gentianella weigendii
(Fabris, 1958). Although in 1916 Gilg described the might be cleistogamous. Self-pollination has been
nectaries of Pitygentias as five calluses between the demonstrated in some Gentianaceae, including some
adnate portions of the stamens, he included in P. high-altitude grassland species in South America
&
thyrsoidea (Hook.) Gilg plants that he (Gilg, 1896) (Freitas Sazima, 2009), but studies of pollination in
had previously described as Gentiana tupa Gilg, in South American Gentianella have remained specula-
which he had were engendered by
said that the nectaries scarcely tive, despite the interest the diverse
conspicuous. The material that he identified as P. floral morphology among these species. Gilg (1916)
&
pinifolia (Ruiz Pav. ex G. Don) Gilg in 1916 reported that the flowers of G. thyrsoidea (as
included flowers preserved in alcohol, received from Pitygentias spp.) appeared to be cleistogamous, as
