Orchid Digest
Volume 60, No. 4 Oct.-Nov.-Dec., 1996


A NEW SPECIES OF TOLUMNIA RAF. FROM PUERTO RICO

RUBEN P. SAULEDA AND MARVIN E. RAGAN


			Ruben Sauleda Ph.D. received his doctorate in biology at the
 University of South Florida (Tampa) with a specialty in plant taxonomy. He has been
 proprietor of Ruben in Orchids in Miami since 1962 and is a well-known and
 accomplished writer on orchids.

			Marvin Ragan has been an avid orchidist for thirty-one years. He
 is owner of MAJ Orchids in Orange Park, Florida and has been recognized as an
 Orchid Identification Authority by the American Orchid Society.

			HISTORICALLY THE GENUS Tolumnia Raf., or the miniature
 oncidiums as they are called in horticultural circles, have been the center of
 controversy and heated debates. In the sixties the debates centered around the 
 delineation of the species, especially the white-flowered species, the classification of 
 which was handled differently from the colored species. Later in the seventies and
 eighties the debate shifted to the generic level. The argument centered on the choice
 of the type species of the genus Oncidium Sw. One interpretation used Oncidium
 variegatum Sw. as the type of the genus. This interpretation would mandate that the 
 miniature Oncidium group would be the "true" oncidiums and all of the other species
 would have to be transferred out of the genus. If O. variegatum was rejected as the
 type of the genus Oncidium, then it could be used to typify of the genus Tolumnia. 
 Proposals were made to the Botanical Congress, all with good merit, and finally the 
 ruling was made that the genus Oncidium was not to be based on Oncidium
 variegatum. This opened the door for the transfer of all the species of miniature 
 oncidiums into the genus Tolumnia. It seems that now we are returning back to the 
 same controversy we had to endure thirty years ago.

			The problem in the sixties revolved around a proliferation of orchid
 literature generated by researchers completely ignorant of basic taxonomic and
 evolutionary principles. At the present time there is a proliferation of literature by
 researchers who although scientifically trained, either do not have a basic
 understanding of the definition of a species and the evolutionary principles involved in
 speciation, or choose to ignore these principles. Many of their interpretations are
 based on conjecture, personal feelings or manipulation of statistical data.

			Several researchers have called the species we are naming in
 this paper Tolumnia variegata. Ackerman first stated that possibly two distinct species
 comprised the Puerto Rico population. Now (1992) he states that the Puerto Rican
 species is Tolumnia variegata, but it has two phenology types which are slightly 
 different morphologically, but the characteristics of the two intergrade. Other
 researchers choose to call all of the white species T. variegata. This would be like 
 calling all of the rock laelias one species, all the purple cattleyas one species or all the
 white Spiranthes one species. Little regard is being given to the basic definition of a
 species: a population of similar individuals which interbreed, sharing a common gene
 pool, but are reproductively isolated from other populations. The white tolumnias very
 clearly follow these rules. The reproductive isolation between most of the species is 
 geographical. The majority of the species are endemic to their respective islands.

			In our estimation it is possible that at one time more than one
 species occurred in Puerto Rico, accounting for the high degree of variation in the
 population. This may be a situation similar to Tolumnia lucayana in the islands of the
 Bahamas. At some time in the past, two or possibly three species occurred in the
 Bahamas, and through natural hybridization and back-crossing a hybrid swarm has 
 resulted. None of the original species are present. A selfing of any of the color forms 
 which have resulted in the hybrid swarm will yield the complete range of variations.

			An exhaustive statistical analysis was made of the Puerto Rico
 population and of Tolumnia variegata and T. leiboldii. Measurements were taken from
 both herbarium specimens, live-collected material and live material which had been
 cultivated for several years to eliminate differences caused by ecological factors.
 Computer programs which generated scatter diagrams, percent similarity and various
 other statistical procedures were used.

			The computer-generated data from the Puerto Rico population can
 be interpreted in three ways: the population in Puerto Rico shares a common gene
 pool, can be morphologically distinguished from the other white species of tolumnias
 and of paramount importance is that it is geographically isolated from any other
 Tolumnia, meaning that it represents either a hybrid swarm or a highly variable
 species.

			After careful morphological study of both herbarium specimens
 and living material, making field observations and collections, and studying the
 statistical analysis, we have concluded that sufficient data exist to confirm that the
 population is distinct from the other white-flowered tolumnias and therefore must be
 described as a new species.

			Tolumnia borinquinensis Sauleda and Ragan, sp. nov. Type: 
 PUERTO RICO: near SW edge of Lago Tortuguero, 2.3 km NE of Manati, 17 Nov 1981,
 Sauleda,Sauleda, Ragan & Hansen 6835 (Holotype: NY; Isotypes: F, FTG, US, USF).

	Crista et isthmus labelli et fundi petalorum colore rubiginosa maculati. Crista
 tuberculis anticis tribus et tuberculis posticis tribus parvioribus.

			Plant epiphytic, rarely epilithic, rhizomatous, to 56 cm tall; root 
 numerous, slender, velamentous; rhizome stoloniferous, to 9 cm long, repent, 
 decumbent, wiry, remotely several sheathed, sheaths scarious, ovate-triangular, acute,
 to 1.2 cm long, 0.6 cm wide; stem flattened, to 0.5 cm long, 0.2 cm wide, completely 
 enclosed by distichous leaves, to leaves; leaves coriaceous, imbricated, produced at 
 intervals along stem conduplicate, falcate, lanceolate, acute, to 14 cm long, 1.6 cm
 wide, margin cartilaginous, serrulate; inflorescence lateral, to 56 cm tall, peduncle
 slender, erect, distantly several sheathed, racemose, rarely particulate above, to 25 
 flowers; floral bracts narrowly lanceolate, concave, acute to acuminate, to 0.6 cm long,
 0.2 cm wide; ovary pedicellate, slender, to 1.6 cm long; sepals white, basal l/3 with
 reddish brown spots; dorsal sepal spatulate, basally clawed, concave, acute, 
 occasionally apiculate, to 0.8 cm long, 0.5 cm wide; lateral sepals lanceolate, concave,
 acute, connate nearly to apex, to 0.8 cm long, 0.1 cm wide; petals white, basal 1/3 with
 reddish brown spots, spatulate, basally clawed, concave, obtuse, to 0.9 cm long, 0.4
 cm wide; labellum three- lobed, white, occasionally with a pink tint, to 1.4 cm long
 1.6 cm wide; lateral lobes basal, linear-elliptic to orbicular, obtuse to broadly rounded,
 margin entire to irregularly crenulate at apex; midlobe separated from lateral lobes by
 a short isthmus isthmus yellow with reddish brown spots, margin usually fringed; 
 midlobe reniform or broadly cordate, emarginate, usually with an apicule in the sinus; 
 callosity on isthmus yellow with reddish brown spots, with three anterior and three
 smaller posterior tubercles; column stout, erect, to 0.4 cm long, 0.2 cm wide, with
 expanded lateral wings projecting from apex, lateral wings white or pink, ovate, base
 obtuse, apex acute, margin irregularly lobed, to 0.2 cm long, 0.1 cm wide, anther cap
 white or pink; capsule pendent, ellipsoid, to 1.8 cm long, 0.8 cm wide.

			Etymology: Derived from the Taino Indian name for the island of
 Puerto Rico, Borinquin, meaning land of the haughty lord.

			Additional Specimens Examined: PUERTO RICO: Rio Piedras, 13
 Jun 1914, Stevenson 1978 (US); west end of Laguna Tortuguero, 27 Mar 1922,
 Britton & Chardon 6825 (NY); 0.8 km SW of Manati, along rt.149, Sauleda et al 6840 
 (USF); Vega Baja, 26 Mar 1906, Britton & Cowell 1432 (NY); 6.4 km SW of Dorado, 24
 Nov 1981, Sauleda et al 6900 (FTG, NY, USF); Utuado, 15-20 Mar 1906, Britton & 
 Cowell 901 (NY); 8 km N of Utuado, along rt. 10, 24 Sep 1982, Sauleda et al 7711
 (USF); 17.9 km S of Cieales, along rt. 149, 28 Nov 1981, Sauleda et al 6941 (USF); 
 Maricao to Monte Alegrillo, 3 Apr 1913, Britton et al 2582 (NY); Reserva Forestal
 Maricao, Monte del Estado, along rt. 120, 1.9 km S of jct with rt. 366, 9 Nov 1983, 
 Sauleda et al 8540A (USF); 1.9 km SW of Comerio, along rt. 156, 25 Nov 1981,
 Sauleda et al 6914 (FTG); Barrio Sonadora de Bayane, 8 Oct 1982, Sauleda et al
 7944 (USF); Reserva Forestal Carite, along rt. 184, 3.2 km E of jct with rt. 152, 4 Nov
 1983, Sauleda et al 8474A (USF); Reserva Forestal Guanica, 4.0 km SE of Guanica,
 along rt. 383, 6 Nov 1983, Sauleda et al 8521 (USF); Mount Mandios, near Jayuya,
 17 Mar 1906, Britton & Cowell 903 (NY); Lares, 22 Nov 1913, Stevens & Hess 4937
 (NY); Playa Sucia Bay, 1 Mar 1915, Britton et al 4747 (NY, US); Abonito, 4 May 1935,
 Sargent 357 (US); Palo Seco, 2 Dec 1919, Stevenson 3312 (US); Aguada, near Rio
 Grande, 4 Mar 1886, Sintenis 5721 (US); between Morovis and Corozal, 19 Mar
 1925, Britton et al 8430 (NY); in ravine, Coamo Springs, 14 June-22 Jul 1901, 
 Underwood & Griggs s.n. (NY); Vieques Island, Calabaza to Ensenada Honda, 18 Feb
 1914, Shafer 2951 (NY, US).

	U.S. VIRGIN ISLANDS: St. Thomas, Flaghill, Oct 1887, Eggers s.n. (US).

			Tolumnia borinquinensis previously was identified as Oncidium
 variegatum Sw. (Britton & Wilson, 1924; Cogniaux, 1910; Moir & Moir, 1970), 
 Oncidium leiboldii Reichb. f. (Britton & Wilson, 1924; Cogniaux, 1910; Leon, 1946;
 Moir, 1962; Moir & Hawkes, 1967; Moir & Moir, 1970, 1973) and Oncidium sylvestre
 Lindl. (Cogniaux, 1910).

			Recent collections of living material of T. leiboldii, a Cuban
 endemic, and of T. variegata, an Hispaniolan endemic, have given us an opportunity 
 to compare living specimens of these with living specimens of the Puerto Rican 
 species. In addition, we have compared the types of T. variegata, T. leiboldii and T. 
 sylvestre with the Puerto Rican material.

			Vegetatively T. variegata and T. borinquinensis are similar. Both
 species have broad coriaceous falcate conduplicate leaves. Tolumnia leiboldii has
 narrow almost terete leaves and T. sylvestre is a small plant with manyleaved 
 elongate growths; these characteristics quickly distinguish them from the other two
 species and therefore they can be eliminated from any further discussion. Tolumnia
 variegata and T. borinquinensis occupy a wide variety of habitats. They can be found
 from xeric habitats at sea level to moist forests at higher elevations, which probably
 accounts in part for their vegetative similarities.

	         Florally, the two species are distinct and can be easily distinguished. The 
 isthmus of the labellum (area between the midlobe and sidelobes) is usually 
 fimbriated in T. borinquinensis, but is entire in T. variegata. The crest sculpturing on
 both species is somewhat similar, both have three anterior tubercles and three
 smaller posterior tubercles. However, the thickness and exact position of the tubercles
 and the degree of development is different but consistent for each species and can be
 used to distinguish the species.

LITERATURE CITED

Ackerman, James D. (Text) and Maruja Del Castillo Mayda (Illustrations). 1992. The
 Orchids of Puerto Rico and the Virgin Islands. University of Puerto Rico Press. San
 Juan, P. R.

Britton, N. L. and P. Wilson. 1924. Scientific Survey of Puerto Rico and the Virgin
 Islands. Orchidaceae 5: 180-217. New York Academy of Sciences.

Cogruaux, C. A. 1910. Orchidaceae, In: I. Urban. Symbolae Antillanae 6: 293-696.
 Reprinted 1964. A. Asher & Co. Amsterdam.

Garay, L. A. and H. R. Sweet. 1974. The Orchidaceae, In R. A. Howard, Flora of the
 Lesser Antilles. Arnold Arb., Harv. Univ., Jamaica Plain, Mass.

Moir, W. W. G. and A. D. Hawkes. 1967. Studies in the Equitant Oncidiums. Phytologia
 15 (1): 2-12.

Moir, W. W. G. and M. A. Moir. 1970. Variegata Oncidiums. Published by the authors.

Moir, W. W. G. and M. A. Moir.1973. Variegata Oncidiums, Part 1. The Florida Orchidist 
16 (3): 124-131.

Acknowledgments

			We wish to thank the directors, curators and staff members of the
 herbaria cited throughout the text for their cooperation and help. We acknowledge the
 generous field assistance given by the late Eugene Antommarchi, Myriam and Sidney
 Antommarchi and Julio Melendez of Puerto Rico, Patricia H. Adams of Boca Raton,
 Florida, Diane K. Sauleda of Miami, Florida and Bruce Hansen of the University of 
 South Florida. Our thanks also are due to Dr. Helen B. Correll for preparing the latin 
 description.

Ruben P. Sauleda
12555 S. W. 46 Street
Miami, FL 33175

Marvin E. Ragan
126 Wild Orchid Lane
Orange Park, FL 32065
32065

Orchid Digest, Oct.-Nov.-Dec. 1996