Lawesson, Jonas Erik

Norman, Elaine

English

Aquatic Commons

BUDDLEJACEAE
A NEW FAMILY FOR GALAPAGOS
by
lonas Erik Lawesson
Charles Darwin Research Station
and
Elaine Norman
Stetson University. DeLand. FL. USA
During a recent survey ofthe vegetation on Floreana Island by Jonas E. Lawesson, resident botanist at the
Darwin Research Station, Yolanda Carvajal, scholarship student, and Halle Zederkof, field assistant,
some unfamiliar tallish trees with many small, fragrant, yellow flowers were found in the area ofCerro de
Naranjos (Orange-trees Mountain). The population of this tree seemed to be well adapted to the higher
more humid part ofthe island, even though it was surrounded by the introduced common guava. Later the
same species was also found in the are a east of Cerro Pajas, close to the Wittmers' farm, in a Scalesia
pedunculata forest. The species is Buddleja americana L., ofthe Buddlejaceae, a fairly common plant on the
continent, occuring from Mexico to Bolivia and on some Caribbean islands (Norman 1982). Buddleja is not
mentioned in the Flora ofthe Galapagos Islands by Wiggins and Porter (1971) and in fact represents a new
family for the archipelago. The only other collection ofthis species 'from the Galapagos was made near the
Wittmers' farm by S. Itow of Japan in 1970. Itow's collection is in the herbarium of the California
Academy of Sciences. His finding has not been reported previously (pers. comm.).
It is strange that this species was not collected prior to 1970, as older settlers report that this Buddleja was
already quite common some 50 years ago (F. Cruz. pers. comm.). Apparently Floreana has never been
sufficiently investigated by botanists, although several endemic and interesting species grow there, such as
Lippia salicifolia, Psychotria angustata. Scalesia vil/osa and Lecocarpus pinnatifidus. It would seem that
Buddleja was simply overlooked by earlier visitors.
Whether the Buddleja is native to Floreana or not is difftcult to sayo As is the case with so many species in
Galapagos, the route by which they arrived in the archipelago is open to speculation. In some cases it is
almost impossible to say whether the plant carne by natural means (floating, by wind or carried by
animals) or was introduced by mano Examples of such doubtful cases are Sapindus saponaria, Solanum
erianthum and Trema micrantha. Floreana was the first island to be colonized by man (Hickman 1985)and
Buddleja could have been introduced accidentally with soil, etc., by early settlers. Buddleja americana is
not known as an ornamental. On the contrary, in the southern provinces ofEcuador it is a weed, invading
pastures and therefore eradicated whenever it appears (F. Cruz, pers. comm.). Thus it seems unlikely that
Buddleja was introduced deliberately.
There is a strong probability that Buddleja is native to Floreana, i.e. it was transported from the South
American continent to Galapagos by natural means. Supporting this view is the fact that the fruits and
seeds of the Buddleja on Floreana are commonly eaten by the local finches, such as the Small Tree Finch
(Carmarhynchus parvulus), Medium Tree Finch (C. pauper) and Warbler Finch (Certhidea olivacea).
Moreover the seeds are easily spread by wind as they are only about Imm.long, fusiform with short wings
at the two extremities. In fact Buddleja americana is the most widespread of New World Buddlejas,
occurring naturally on islands such as Cuba and Jamaica. That Buddleja appears to be limited to one
island in the Galapagos may indicate that it is a fairly recent arrival which has not had a chance to colonize
suitable habitats on other islands. In any case, the record adds a new family to the flora of Galapagos.
The fact that such a large plant as Buddleja was overlooked stresses the necessity for further botanical
research on the island. Many more interesting findings and surprises might come to light. However, unless
active conservation measures are instituted, the possibility of further botanical research on Floreana may
soon disappear. Because ofthe serious problems caused by introduced plants and animals, which threaten
the local flora and fauna (Cruz et al. 1986), the situation on the island is alarming. Something must be done
now if the island's native biota is to be saved.
28
Noticias de Galapagos v.45 1987


Buddlejaceae - a new family for Galapagos

http://aquaticcommons.org/4678/1/NG_45_1987_Lawesson%26Norman_Buddlejaceae.pdf

Buddlejaceae - a new family for Galapagos

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