The whole day was devoted
to discussion of taxonomic and nomenclatural problems in
Copiapoa with the general
aim of reaching a consensus on improvements which could be made to the
listing in the CITES Cactaceae Checklist, for which the adviser was
Nigel Taylor. lt was also hoped the discussion would help to reconcile
various differences between the Checklist treatment, that by Graham
Charles in his Cactus File Handbook 4:
Copiapoa (1998) and that
proposed by Fred Kattermann for his forthcoming book The Cacti of
Chile.
The genus does not readily
lend itself to division into clearly definable groups, though C.
solaris, first described by Ritter as the distinct monotypic genus
Pilocopiapoa, is generally accepted to merit a subgenus, as Ritter
himself later proposed (Kakteen in Südamerika 3: 1046. 1980). Ritter
(l.c.) divided subg. Copiapoa
itself into four unnamed sections, an arrangement which
seemed to Taylor, in his commentary on the genus (Cact. Succ. J. Gr. Brit.
43(2/3): 49-60. 1981), “by and large, to make sense“, with the reservation
that “considerable [page5] further field study - by someone with a
synthetic approach - is necessary if a key is to be constructed and proper
species-limits established‘.
In the past 20 years,
considerable further field study has been made, jointly and
independently, by several of
those present at the meeting, and by others,
but the genus remains, in the words of Fred Kattermann, “a can of worms“.
As yet there are no molecular data to assist in defining or redefining
species-groups and we are dependent on the sort of criteria used by
Ritter. The plants exhibit remarkable diversity of vegetative form, but
the flowers, fruits and seeds seem to offer little help in classification.
The topic is made more perplexing by the frequent occurrence of two or
more (up to six or seven!) arguably distinct taxa in a single locality (as
recorded in the literature), though not necessarily all at the same
altitude or in the same ecosystem. Uncertainty and confusion over the
identity of taxa found by early collectors such as Bridges and Philippi
have multiplied the nomenclatural problems. Nevertheless, as Nigel Taylor
reminded us at the commencement of the discussion, different members of
one species group do not, as a rule, grow sympatrically; therefore, where
several members of a genus are found in one locality, it is reasonable to
assume that they must belong to different groups (though the possible
occurrence of hybrids or hybrid swarms must not be overlooked). Hence a
helpful way to structure the discussion would be to list the taxa locality
by locality and try to assign them to groups, and this procedure was
adopted by the meeting.
Leaving aside C.
solaris and the distinctive C. echinoides (syn. C. dura, C.
cuprea), four species-groups were initially suggested, broadly
corresponding to Ritter‘s Sections 2-5, though they would not necessarily
include all the species listed by Ritter:
-
Humilis
group
(Ritter‘s Sect. 3)
-
Marginata
group
(Sect. 2 and Sect. 4 in part)
-
Cinerea
group
(Sect. 5)
-
“The Rest“
(C. cinerascens
and others; Sect. 4); later divided into three
subgroups
Acronyms for the various taxa discussed and accepted during the day were then entered in columns
(headed H, M, C and R) on a large-scale sketch-map.
Throughout the day, colour
transparencies to be published in Fred Kattermann‘s book were projected as
a basis for discussion of localities and species-concepts, and a second
projector and screen enabled the plants shown to be compared
simultaneously with others photographed by Graham Charles and other
participants (Roger Ferryman, Paul Hoxey and Nigel Taylor).
Initial discussion centred
on the relationships of C. tocopillana and C. tenuissima.
The consensus was that the former is at best a subspecies of C. humilis
but that the latter (which lacks a valid name) is more closely allied
to C. hypogaea, and that both C. tenuissima and C. laui
might best be treated as subspecies of C. hypogaea. No
conclusion was reached, however, as to the group [page 6] affinity
of C. hypogaea itself. C. mollicula, which was treated by
Charles as a synonym of C. hypogaea, was thought to be more closely
related to C. megarhiza.
A long discussion centred
on the several species reported from the area of Miguel Diaz and the
Quebrada Botija, c. 50 km N of Paposo. Besides C. solaris, and
C. atacamensis, these include a miniature relative of C. cinerea
and another taxon both of which are believed to await formal
description and naming (see comments and illustrations by Graham Charles
in his book, p. 6). The first, a coastal species which forms large clumps
of small heads, has been generally thought to be Ritter‘s C.
varispinata (FR 1447), but it does not fit his description. Though
Ritter gave an exact type locality (50 km N of Paposo and 30 km S of
Blanco Encalada, “auf Küstenbergen“), a plant which does fit C.
varispinata has been found by Roger Ferryman at higher elevations and
by Nigel Taylor at Q. Vizcuña and is closely related to C. humilis,
of which it could be treated as a subspecies. The second undescribed plant
from Botija, earlier thought by Charles (l.c.) to be a variety of C.
cinerea, is currently known simply as “sp. Botija“. lt may be related
to C. marginata and Charles now agrees.
Another interpretation of
C. varispinata, suggested by Fred Kattermann (see CSI 11: 25), is
that it was Philippi‘s Echinocactus conglomeratus (treated by
Britton & Rose as a synonym of C. cinerascens) and therefore the
true “Copiapoa conglomerata“.
Unfortunately, the latter name is problematical,
having been misapplied (by Lembcke) to C. solaris, and the meeting
agreed with Nigel Taylor that it should not be taken up for C.
varispinata as this would simply create further confusion.
The name C. atacamensis
was proposed in 1980 by H. Middleditch for the plant long thought to
be the true C. marginata but treated as C. boliviana by
Ritter. lt is similar to C. calderana, which occurs 300 km further
south. Both were regarded by Fred Kattermann as doubtfully distinct from
C. marginata itself, but both have mucilage which C. marginata
does not [but see comment by Kattermann, p. 17 - Ed.]. In the
circumstances, the meeting considered C. atacamensis could be
treated as a subspecies of C. calderana.
The area richest in
Copiapoa taxa lies
between Paposo and Barquito, south of Chañaral. Here the Humilis group is
represented by C. humilis itself, for which the type locality was
near Paposo. Probable representatives of the Marginata group are C.
montana (N of
Taltal), C. rupestris (Cifuncho), including C. rubriflora (S
of Taltal) and the mound-forming C. desertorum (Cifuncho) which may
be best treated as a subspecies of C. rupestris. Fred Kattermann
identifies C. taltalensis as the first-described of these Marginata
group species, but this point was strongly disputed by others present, who
accept the opinion of P.C. Hutchison (Cact. Succ. J. (US) 25: 37. 1953)
that it is closely related to C. humilis. (lt has been treated as a
synonym of C. humilis in both editions of the CITES Cactaceae
Checklist.) [See footnote, p. 8.]
The coastal belt between Paposo and Chañaral is also the main distribution area of the Cinerea
group, with C. haseltoniana (syn. C. gigantea) the most
[page 7] northerly of the forms here. Discussion over the status and
relationships of this, C. cinerea itself, and its other distinctive
variant, C. krainziana, led the meeting to prefer retaining all
three as separate species pending further study. It
was also recommended that C. longistaminea (Esmeralda), which was
thought by Ritter to be related to C. cinerea, should be kept
separate. Its mucilaginous stems suggest it might be allied, not to C.
cinerea, but to C. calderana (Caldera), and the fact that it
grows with the columna-alba form of C. cinerea, which is
nonmucilaginous and lacks tuberous roots, supports this view.
Intermediates between
C. cinerea and C. serpentisulcata are found between Cifuncho
and Esmeralda, implying that typical C. serpentisulcata, which
Ritter described from N of Chañaral, could be another member of the
Cinerea group.
Around and to the south of
Esmeralda there are several more species not readily assigned to the Humilis, Marginata or Cinerea groups, and mostly assigned by Ritter to his
“Sektion 4“, i . e. “The Rest“. These can be divided into three separate
groups: C. hypogaea and C. laui (these can occur together
but there may be a sterility barrier between them, e.g. ploidy level);
C. cinerascens and C. grandiflora; and C. mollicula and
C. esmeraldana, which were felt to belong with C. megarhiza
(from Paipote, near Copiapo) after comparison of Fred Kattermann‘s
close-ups of their flowers (broadly campanulate) with those of C.
hypogaea and C. laui (funnelform) and C. megarhiza
(broadly campanulate). As well as the contrast in flower-shape,
differences in the form of the pericarpel and nectar-chamber and in the
length of the stamens were noted. Like the differences in stigma-form
thought by Fred Kattermann to distinguish various species (e.g. C.
cinerascens from C. grandiflora and C. longistaminea
from C. cinerea sens. lat.), these features may not be very
reliable as taxonomic characters but merit further study.
South of Chañaral, the Marginata group is represented by C. calderana and south of Caldera
itself by typical C. marginata. There is an apparent break in the
distribution of the Humilis group, with its last presumed member (to be
treated as a subspecies?), C. longispina, being found in the Sierra
Hornillos, S of Copiapo, but C. hypogaea occurs in the coastal
hills as far as south as the Copiapó valley.
Somewhat confusingly, in
view of their similar names, C. echinata and C. echinoides
occur together in the northern part of the range of C. echinata
near Carrizal Bajo. One of them is likely to prove a member of the
Marginata group, with C. echinoides (roots non-tuberous) the
preferred candidate since C. echinata (roots tuberous) has been
variously treated as a variety of C. megarhiza or as a synonym of
C. fiedleriana.
The Cinerea group is
represented in the coastal zone N and S of Carrizal by its southernmost
member, known either as C. dealbata Ritter (C. cinerea var.
dealbata (Ritter) Slaba) or by the earlier name C. malletiana
(Lemaire ex SalmDyck) Backeberg which was preferred in both editions
of the CITES checklist. Echinocactus malletianus Lemaire ex
Salm-Dyck pre-dates E. cinereus Philippi, the basionym of C.
cinerea, and so would have priority over this well-known name [page
8] in a unified concept of the species, but it has no type. Taking
these points into consideration, Nigel Taylor conceded that it might be
preferable to use the better known and better typified name C.
dealbata.
The southernmost member of
the genus is C. coquimbana, which has a range of some 300 km from
Huasco to south of Fray Jorge. North of the Huasco river it is replaced by
C. fiedleriana which links it to C. echinata. Hoffmann and
Charles treat C. fiedleriana as a variety of C. coquimbana;
in CCC2 it was accepted, with C. echinata as a synonym; Fred
Kattermann thinks it “fits the overall C. marginata complex“. Who
is right? The “clear and precise differences“ sought by Fred in his
population studies certainly seem elusive, as he says, and this is only
one instance in Copiapoa
where the search for such differences, which are
essential to the preparation of a workable identification key, has so far
been unsuccessful.
Not surprisingly,
therefore, taxonomic conclusions reached at the meeting were very
tentative. There was, however, general (if not unanimous) agreement on
various points relating to the questions posed by Hunt (CSI 11: 24-28) and
his proposals (l.c. 28-29) made in the light of the initial responses by
Charles, Kattermann and Taylor. The proposals were duly amended to read as
follows:
-
C. atacamensis.
Treat as a subspecies of C. calderana*.
-
C. bridgesii.
The original Echinocactus bridgesii Pfeiffer (1847) was probably
a redescription of E. echinoides
Lemaire ex Salm-Dyck (1845) and should therefore be treated as a synonym
of C. echinoides. (E. bridgesii hort. is referable to C.
marginata.)
-
C.
conglomerata. Re-use of this name for an accepted species would
cause confusion.
lt should be rejected.
-
C.
fiedleriana. No change at present.
-
C. laui.
Retain as species pro tem.
-
C.
longistaminea. Accept, at least provisionally*.
-
C.
malletiana. Treat as an uncertain synonym of C. dealbata.
-
C. montana,
C. olivana and C. rupestris.
Accept C. montana
(syn. C. olivana) and
C. rupestris (both
members of the Marginata group), as in CCC2.
-
C. taltalensis.
This is almost certainly a form of C. humilis. Mats Hjertson will
check for isotype material at Stockholm, the holotype at Berlin having
been destroyed**.
-
C. tenuissima
and C. tocopillana. C. tenuissima appears to be a form of
C. hypogaea, but C. tocopillana should be treated as a
subspecies of C. humilis.
