Flora of Dominica, Part 2 - Smithsonian Institution Libraries

NUMBER 77 5
Sugar Loaf Estate: An estate just across the Indian River
from Portsmouth. Eggers also collected here, e.g., no. 723
(Blepharocalyx eggersii). Other collections are 717 (Connarus
grandiflorus), 753 (Licania leucosepala), and 1084 (Byrsonima
lucida).
ENDEMISM IN DOMINICA
The flora of Dominica is most similar to that of the nearby
French islands, Guadeloupe and Martinique. Several factors
affect supposed endemics of Dominica and/or the French
islands, new records, changes in taxonomic concepts, and
errors of identification or locality.
New records of species thought endemic to Dominica have
recently been found on the French islands, and species thought
endemic to the French islands have been found on Dominica.
The recent publication of Fournet (1978) enables one to check
whether or not a given species, supposedly endemic to
Dominica, actually is now known on the French islands.
Examples: Gonocalyx smilacifolius (Ericaceae), thought to be
endemic to Dominica, has been collected on Guadeloupe.
Oreopanar dussii (Araliaceae), previously thought to be only
on the peaks of the French islands, has now been collected on
Dominica.
Changing species concepts also affect endemism. As more
specimens become available it becomes possible to recognize
that something that seemed quite distinct, perhaps only known
from one collection in a rather extreme aspect, is only part of a
continuous range of variation observable when many collections
are studied. Piper dominicanum cannot be maintained as
distinct from the variable and wide-ranging species, Piper
aequale.
An example of an error in identification is provided by the
supposed endemic of Dominica Morisonia imrayi (Capparaceae).
Its type is a misidentified specimen of Styrar glaber
(S tyracaceae).
Errors in locality information arise from three sources: (1)
confusing Dominica with the Dominican Republic, (2) assumption
of occurrence in Dominica from published generalized
distribution statements, and (3) mislabeling of collections from
the French Islands as from Trinidad.
Confusion between Dominica and the Dominican Republic
(on Hispaniola) is occasionally found in monographs and
revisions, i.e., citing an Imray specimen from the Dominican
Republic, when it actually was from Dominica. The reverse
rarely occurs, citing Dominican Republic material as if it were
from Dominica.
Some questionable records for species on Dominica have
been traced to Velez’ compilation (1957), “Herbaceous
Angiosperms of the Lesser Antilles.” Most of these questionable
records proved to be based on generalized distribution
statements in works like Britton and Wilson’s “Flora of Port0
Rico” (1923-1925) such as “Anguilla to Barbados.” In such
cases, Velez inserted a B (for Britton) in the column for
Dominica. If a confiing specimen was not located, an
arbitrary decision was made for handling the species involved.
It was included if its occurrence on Dominica seemed
reasonably probable or it was listed as excluded if its
occurrence seemed improbable.
According to C. Denis Adams (in litt.), there are some sixty
records of Trinidad plants that are known only from Sieber “Fl.
TMitatis” specimens and have not been recollected on that
island. Franz Wilhelm Sieber financed collecting trips of Franz
Kohaut to Martinique (1819-1821) and Franz Wrbna to
Trinidad (1822) and distributed the specimens, labeling the
former as Fl. Martinicensis and the latter as Fl. Trinitensis
under his own name and numbers. It is supposed that the sixty
anomalous records were actually collected by Kohaut and were
inadvertently mislabeled as “Fl. Trinitatis,” possibly at least
partially involving a confusion with the town of La Trinite on
Martinique. Three of these are listed in the following list as
restricted to Dominica and the French Islands, Rauvolfia
biauriculata, Critonia macropoda, and Marcgravia trinitatis.
The following list was prepared from information available
to me for those interested in endemism involving Dominica and
the French Islands. An asterisk (*) denotes a species possibly
rare and endangered; species names in upper case are believed
to be endemics of Dominica; species known to occur beyond
Dominica and the French Islands are not normally included,
unless they seem to be rare. There are a dozen or two species
that also reach Montserrat, St. Lucia, and/or St. Vincent.
Amonoa coriboeo (Euphorbiaceae): carapite, Dominica and Guadeloupe.
Anibo romogeono (Lauraceae): Dominica and Martinique.
Begoniu obliqua (Begdaceae): common on Guadeloupe to Madnique.
BESLERIA PETIOLARIS (Gesneriaceae): only on Dominica, common.
Charionthus corymbosus (Melastomataceae): Guadeloupe to Martinique,
possibly St. Lucia.
CHARIANTHUS PURPUREUS var. RUGOSUS (Melastmataceae): only on
Dominica.
*Chiononthus dussii (Oleaceae): supposedly endemic to Martinique but known
from at least one collection from Dominica.
CHROMOLAENA IMPETIOLARIS (Asteraceae): only on Dominica, at higher
elevations.
CHROMOLAENA MACRODON (Asteraceae): only on Dominica but possibly
also on St. Kitts.
Chromoloeno trigonmorpa (Asteraceae): Guadeloupe to Martinique but
possibly elsewhere in the Lesser Antilles.
Clidemio guadalupensk Melastomataceae): Guadeloupe and Dominica.
Clusio mangle (Clusiaceae): kaklin, a dominant in peak forests from
Guadeloupe to Mamnique.
*Critoniu mocropoda (Asteraceae): Once recently collected on Dominica,
possibly earlier (by Eggen). Also known from NE Martinique. The
attribution of the type to Trinidad is believed to be an error.
Duronto stenostochya (Verbenaceae): Martinique and Dominica. Foumet said
it was originally from Brazil.
EUGENIA HODGEI (Myaaceae): only on Dominica but a dominant in the
Mome Gay area.
Eugenia octopleuro (Myrtaceae): Guadeloupe to Martinique, possibly also in
Central America.
Exostemo sanctoe- lube (Rubiaceae): Dominica to St. Vincent.
*Freziero cordato (Theaceae): mountain top from Guadeloupe to Martinique.
Freziero unduloto var. elegans (Theaceae): Guadeloupe to Martinique.