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| Cyne barcelonae Nickrent & Rule, in Nickrent & Rule, 2022. |
Abstract
A new species of Cyne (Loranthaceae) from Bucas Grande and Dinagat Islands, Philippines is described and named C. barcelonae in honor of the Filipina botanist Julie F. Barcelona. Phylogenetic analysis using the complete nuclear ribosomal DNA cistron confirms it is sister to C. banahaensis, the only species among the six in the genus with complete descriptions of floral morphology. The species is similar to the rare C. perfoliata of Papua New Guinea by having connate-perfoliate upper leaves but differs from others in the genus by possessing palmate leaf venation, inflorescences lacking an operculum, light green corollas, and stamens with filaments. No type material for Cyne quadriangula exists, thus this taxon is only known from the original protologue. It was rediscovered on Bucas Grande Island and that collection was described and used as the neotype for the species. A revised description of the genus and key to the seven species is provided.
Keywords: Caraga region, mistletoe, parasitic plant, Santalales, Eudicots
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| Cyne barcelonae, sp. nov. A. habit of mistletoe parasitic on Myrsine sp. B. A young haustorial connection to host branch. Arrow indicates a new vegetative shoot forming on the flank of the haustorium. Note that no epicortical roots are present. C. Terminal portion of vegetative shoot showing two lateral and the central stems assuming a pseudo-whorled appearance. Note the connation of the leaf bases. D. Non-connate leaves subtending to young shoots with connate leaves, still unopened. E. Young inflorescence with one of the connate leaves removed. Although two pairs of triads can be discerned, their decussate nature is obscure. F. Flowering shoots of plant photographed on Dinagat Island by M. Demetillo. Photos A-E by M. G. Q. Rule. |
Cyne barcelonae Nickrent & Rule, sp. nov.
Diagnosis:—Similar to C. perfoliata by its basally connate upper leaves and to other species by its possession of sessile decussate pairs
of triads composed of 6-merous flowers with a style articulated above the base. It differs from these by having palmate (vs. pinnate)
leaf venation, inflorescences that lack an operculum (vs. with an operculum), light green corollas (vs. yellow, red, etc.) and stamens
with filaments (vs. sessile anthers).
Etymology:—This species is named in honor of the Filipina botanist Dr. Julie Fenete Barcelona (1972 – ) who has made major contributions to our knowledge of the Philippine flora, particularly for pteridophytes and Rafflesia.
Cyne quadriangula Danser, Philipp. J. Sci. 58: 38 (1935)
Conclusions:
It appears that the presence of an operculum cannot now be used as a diagnostic feature of all Cyne species. Despite
this, corky periderm tissue subtending the inflorescences, whether it enlarges upon flower maturation or not, may be present among all the species. The well-documented floral features of C. barcelonae, C. banahaensis, and C.
quadriangula reported here expand the range of morphological character states known for the genus. It is clear that
for the remaining species much more morphological information, obtained from living material, is required to fully
understand interspecific relationships and to confirm placement within Cyne (e.g. C. monotrias). Although it is
encouraging that new populations of the three Philippine Cyne species have been discovered, continuing environmental
degradation, from both natural and anthropogenic causes, decreases the prospect of rediscovering and documenting the
exceptionally rare C. baetorta, C. monotrias, C. papuana, and C. perfoliata. Because of their complex life histories
and existence at higher trophic levels, these mistletoes are extremely sensitive to environmental perturbation, thus their
conservation should be of high priority. In fact, the presence of such rare mistletoes could be used to monitor overall
ecosystem health.
Daniel L. Nickrent and Mark Gregory Q. Rule. 2022. An Evaluation of the Genus Cyne (Loranthaceae) including A New Species and Rediscovery and Neotypification of the Rare C. quadriangula. Phytotaxa. 558(1); 67-80. DOI: 10.11646/phytotaxa.558.1.4
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