The subtribe Laeliinae was proposed by Bentham (1881), remodeled by Pfitzer (1889), and comprehended, in Dressler's system (1993), 45 genus. Although another system proposed (Szlachetko, 1995) has divided the subtribe into three (Laeliinae, Epidendrinae and Ponerinae), recent molecular studies (van den Berg et al., 2000; van den Berg et al., 2002) confirmed the included of the most genus of Dressler's (1993). Just Dilomilis and Helleriella were excluded to Pleurothallidinae and Ponera and Isochilus to Ponerinae (which has, based on DNA, a very distinct composition from this one proposed by Szlachetko). Besides, the molecular data show that Arpophyllum and Meiracyllium (members of another subtribes in Dressler's system) are also part of Laeliinae. Inside the subtribe the variation of DNA is small, which makes difficult detailed grouping but are visible in some main groups of genera. Recent studies not still published with three regions of distinct DNA (ITS, trnL-F e matK) suggest the follow structure of genera inside the subtribe :
a) Pseudolaelia group: this includes mainly Brazilian genera, in general, with a short and wide column, small lateral lobos and nectaries at the base of the lip: Isabelia (including Neolauchea and Sophronitella), Pseudolaelia, Constantia, Leptotes and Loefgrenianthus. Although it has not been sequentialed, probably the genus Pygmaeorchis will be included here.
b) Encyclia group: Encyclia, Artorima, Alamania, Prosthechea, Euchile, Oestlundia.
c) Broughtonia group: this is a small collection of, in general, Caribbean genera : Broughtonia (including Cattleyopsis and Laeliopsis), Psychilis, Tetramicra, Quisqueya and probably Dinema and Nidema.
d) Scaphyglottis group: this genera normally present a column foot (but not all of them): Scaphyglottis (including Hexisea, Tetragamestus, Reichenbachanthus), Dimerandra, Jacquiniella and Acrorchis.
e) Domingoa group: Domingoa (including Nageliella), Pinelianthe (including Homalopetalum).
f) Laelia group: Just the genus Laelia (just the Mexican species and also Schomburgkia)
g) Epidendrum group: Epidendrum, Oerstedella, Barkeria, Orleanesia and Caularthron.
h) Cattleya group: Cattleya, Brassavola, Sophronitis, Rhyncholaelia, Guarianthe and probably Meiracyllium (and finally the genus described in this paper).
The first evolutionary lineages in the Cattleya group were Meiracyllium, Rhyncholaelia and Guarianthe, suggesting a Mexican origin for the distribution of the group, with subsequent dispersion to South America. Molecular studies of Brazilian species previously placed in Laelia showed that these constitute a closely related group with Sophronitis and can included in the latter (other authors prefer to divide these species in several small genera). Studies in Cattleya showed that some groups of species previously included in the genus were placed in a distinct phylogenetic position. One of these presents only four species and was separated to Guarianthe (the group of C. skinneri, Dressler & Higgins, 2003). It presents slightly distinct floral morphology, and occurs mainly in Central America, whereas the remaining of the genus is essentially South American. Another two species that do not fit Cattleya well are C. araguaiensis and C. maxima. The latter presents is morphologically similar to the Cattleya labiata complex and is still under study, whereas C. araguaiensis presents a unique morphology. When Pabst (1967) described this species, he chose to place it in Cattleya because of the four pollinia, however, details in the column, especially the two hook-shaped auricules pointing upwards and the shape of the anthers are unlike any other genus of the Cattleya group. Vegetative characters, on the other hand, suggest slight neoteny (when an individual reaches the reproductive stage despite a delay in the vegetative development), since the small plants of this species could be easily mistaken by young plants of Cattleya, Guarianthe or Sophronitis (sensu lato). Therefore, we decided to split this species to a new genus due to its morphological and evolutionary isolation. The lip of C. araguaiensis is not trilobed as the species of bifoliate Cattleya and presents smooth margins with ondulation, more reminiscent of Guarianthe than unifoliate Cattleya. Pabst (1967) described C. araguaiensis from the municipality of Pium, northern portion of Bananal Island, nowadays in Tocantins State, Brazil. However, this species has also been collected in a reasonably broad zone in southern Pará.
Cattleyella Van den Berg & M. W. Chase Boletim CAOB 52 – 99:101
Plantae epiphyticae pseudobulbis cylindricis internodiis tribus amplitudine dissimilibus, folium unum anguste ellipticum, inflorescentia uniflora vel raro biflora cum spatha. Sepala petalaque similia ex bruneo viridiflava. Labellum fere indivisum lobis lateralibus columnam involventis et lobis terminalibus ad marginem integris. Columna cum auriculis duobus unciformibus, anthera galeata. Pollinia 4 caudiculata.
araguaiensis (Pabst) Van den Berg & M. W. Chase
araguaiensis f. alba (L. C. Menezes) Van den Berg & M.
CHRISTENSON, E. A. 1996. Notes on Neotropical Orchidaceae II. Lindleyana 11: 12-26.
DRESSLER, R. L. 1993. Phylogeny and classification of the orchid family. Dioscorides Press, Portland.
DRESSLER, R. L. e HIGGINS, W. E. 2003. Guarianthe, a generic name for the “Cattleya skinneri" complex. Lankesteriana 7: 44-46.
PABST, G. F. J. 1967. Additamenta ad orchidologiam brasiliensem – VIII. Orquídea 29: 5-22.
PFITZER, E. 1889. Orchidaceae. Páginas 52-222 in ENGLER, A. e PRANTL, K. (eds.) Die Natürlichen Pflanzenfamilien Ergänzungsheft.
SZLACHETKO, D. L. 1995. Systema Orchidalium. Fragmenta Floristica et Geobotanica Suppl. 3: 1-152.
VAN DEN BERG, C.; HIGGINS, W. E.; DRESSLER, R. L.; WHITTEN, W. M.; SOTO ARENAS, M. A.; CULHAM, A.; CHASE, M. W. 2000. A phylogenetic analysis of Laeliinae (Orchidaceae) based on sequence data from internal transcribed spacers (ITS) of nuclear ribosomal DNA. Lindleyana 15: 96-114.
VAN DEN BERG, C.; HIGGINS, W. E.; DRESSLER, R. L., WHITTEN, M. W., CULHAM, A., CHASE, M. W. 2002. Molecular systematics of the Laeliinae. Páginas 170-176 in CLARK, J.; ELLIOTT, W. M.; TINGLEY, G.; BIRO, J. Proceedings of the 16th World Orchid Conference (Vancouver). Vancouver Orchid Society, Vancouver.
Dr. Cássio van den Berg
Dr. Mark W. Chase
The editors of Boletim CAOB (page 2, # 53), due to the publication done in # 52, about the new nomenclatural combination Cattleyella, inform bellow its synonyms, the last of them described in Richardiana Vol. IV (2), April 2004. It occurred due to the precedence of the Brazilian publication.
araguaiensis (Pabst) Van den Berg & W. M. Chase
Photo: Marco Campacci