Ann. Bot. Fennici 35: 21–27 Helsinki 21 April 1998 ISSN 0003-3847 © Finnish Zoological and Botanical Publishing Board 1998 A new definition of the genus Tamayorkis (Malaxideae, Epidendroideae, Orchidaceae) Roberto Gonzalez Tamayo & Dariusz L. Szlachetko Tamayo, R. G., Instituto de Botánica CUCBA, Universidad de Guadalajara, Apdo. Postal 139, 44100 Zapopan, Jalisco, México Szlachetko D. L., Department of Plant Ecology and Nature Protection, Gdansk University, Al. Legionów 9, PL-80-441 Gdansk, Poland Received 23 September 1997, accepted 17 February 1998 Tamayorkis Szlach. (Malaxideae, Epidendroideae, Orchidaceae) is redefined and three additional species, T. ehrenbergii (Rchb.f.) R. Gonzalez & Szlach., T. hintonii (Todzia) R. Gonzalez & Szlach. and T. wendtii (Salazar) R. Gonzalez & Szlach. are incorporated into it. Tamayorkis is compared with Malaxis Solander ex O. Swartz and Liparis L. C. Richard, to which it is closely related. Key words: angiosperms, nomenclature, Orchidaceae, Tamayorkis, taxonomy A monotypic genus Tamayorkis Szlach. was proposed by Szlachetko (1995), based on Microstylis platyglossa Rob. & Greenm. Two species previously published in Orquidea (Mex.), Malaxis hintonii Todzia (Todzia 1993) and M. wendtii Salazar (Salazar 1993), were not taken into account at that time. However, after combining our files on the subject we have concluded that M. hintonii, M. wendtii and Microstylis ehrenbergii (Rchb.f.) Kuntze all pertain to Tamayorkis. Consequently, the genus is redefined to include three additional species. Tamayorkis Szlach. descript. emend. Plants terrestrial, herbaceous, pseudobulbous, erect, up to 50 cm tall. Leaf single, convolute, not plicate. Inflorescence terminal, elongate, spicate, many-flowered. Flowers small, resupinate, green or purple in colour. Sepals free, spreading, simi- lar. Petals linear-oblong, recurved or reflexed. Lip attached to base of column, sessile, entire to subhastate or triangular with basal sides curved upward, about same length as other parts of perianth, disk provided at base with an oblong transverse callus thickening. Gynostemium erect or subspread, short, cylindrical, clinandrium spacious, perpendicular to face of column, entire, descending in front at each side of stigma in a groove. Rostellum short, semicircular or triangular, producing two well-separated, translucent, semiliquid viscidia. Stigma concave and ample, about half the length of the column. Anther apical, situated on top of column, firmly and widely fused with the gymnostemium, immovable; connective wide, forming a roof above the locules, concave to almost flat; locules parallel, cucullate, opening apically. Pollinia 4, in two pairs, in each pair the units equal each other, collaterally united. This article is also available in pdf format at http://sekj.pc.helsinki.fi/Journals 22 Tamayo & Szlachetko • Type: Tamayorkis platyglossa (Rob. & Greenm.) Szlach. — Microstylis platyglossa Rob. & Greenm. The taxa of Tamayorkis usually grow at high elevations, up to 3 700 m altitude in rocky places, or in deep humus soils in Abies or other coniferous forests. Most localities can be covered by snow during winter. These are among the few terrestrial orchids in Mexico and Guatemala that can withstand such severe conditions. In the closely related Malaxis Solander ex O. Swartz the flowers are always non-resupinate with the lip very frequently with a basal transverse porrect lamella, but never with a basal, more or less concave callus thickening. The straight column is very short and thick, rarely exceeding 1 mm in length and is dorsiventrally flattened. The anther is erect and the connective much thinner. The 4 pollinia are united in pairs, and in each pair the units are imbricated and unequal. The stigma occupies less than half of the ventral surface of the column, and lacks a descending furrow from the clinandrium on each side. Another genus closely related with Tamayorkis is Liparis L. C. Richard. It has resupinate flowers, in which the lip has upturned basal sides, the lip is never concave, and has a basal, variously shaped callus thickening. It has an arcuate column that is more or less elongated, larger than that of Malaxis and ventrally flat, commonly sulcate in front. The anther is incumbent and the connective thick, broad and movable. The 4 pollinia are united in pairs, the unit of each pair is collateral, equal in size and form. The stigma occupies a small portion of the ventral face of the column. It can be concluded from this brief comparison that Tamayorkis is somewhat intermediate between Malaxis and Liparis sensu lato, in fact more closely related to the latter than to the former due to the collateral units of pollinia in each pair. This explains, in part, why authors in the past have overlooked it. At present the genus embraces four species native to the southern United States, México and Guatemala. Tamayorkis platyglossa (Rob. & Greenm.) Szlach. (Fig. 1) Basionym: Microstylis platyglossa Rob. & Greenm., Proc. Am. Acad. 32: 35. 1985. ANN. BOT. FENNICI 35 (1998) Tamayorkis ehrenbergii (Rchb. f.) R. Gonzalez & Szlach., comb. nov. (Fig. 2) Basionym: Microstylis ehrenbergii Rchb. f., Linnaea 22: 835. 1849. Tamayorkis hintonii (Todzia) R. Gonzalez & Szlach., comb. nov. (Fig. 3) Basionym: Malaxis hintonii Todzia, Orquidea (Mex.) 13(1– 2): 121–124. 1993. Tamayorkis wendtii (Salazar) R. Gonzalez & Szlach., comb. nov. (Fig. 4) Basionym: Malaxis wendtii Salazar, Orquidea (Mex.) 13(1– 2): 281–284. 1993. Key to the species of Tamayorkis 1. Flowers not densely papillose; lip ovate-triangular to broadly triangular .................................................... 2 1. Flowers densely papillose; lip subhastate-triangular 3 2. Lip longer than broad, rounded and slightly dilated at base, lacking basal lateral angles .................... ..................................................... T. ehrenbergii 2. Lip broader than long, provided with basal lateral angles .......................................... T. platyglossa 3. Inflorescence comparatively laxly flowered; flowers light green ................................................ T. hintonii 3. Inflorescence comparatively dense; flowers dark purple ................................................................... T. wendtii In this paper we have accepted the names Malaxis hintonii and M. wendtii, but their nomenclatural status is open to question. Malaxis hintonii agrees in every detail with the description of Microstylis arachnifera Ridley, reduced by Williams (1950) to synonymy of Malaxis ehrenbergii. Also, Malaxis wendtii agrees well with the description of Microstylis porphyrea Ridley (= M. purpurea S. Wats.), also reduced by Williams (1950) to the synonymy of Malaxis ehrenbergii. Furthermore, the type of Microstylis purpurea S. Wats. was collected in southern Arizona in the Huachuca Mountains and Todzen (1995) says that “all specimens of M. ehrenbergii examined at ASU, TUC, NMC and UNM that are from Arizona or New Mexico show the papillae characteristic of M. wendtii as do specimens from Durango and Sonora.” ANN. BOT. FENNICI 35 (1998) • A new definition of the genus Tamayorkis 23 Fig. 1. Tamayorkis platyglossa (Rob. & Greenm.) R. Gonzalez & Szlach. (from Greenwood & Gonzalez s.n., Herb. Tamayo). — A: Habit. — B: Part of inflorescence. — C: Flower, front view. — D: Flower, side view. — E: Floral bract. — F: Floral segments (R. G. Tamayo del.). 24 Tamayo & Szlachetko • ANN. BOT. FENNICI 35 (1998) Fig. 2. Tamayorkis ehrenbergii (Rchb. f.) R. Gonzalez & Szlach. (from Ray s.n., Herb. Tamayo). — A: Habit. — B: Flower, side view. — C: Flower, front view. — D: Floral segments. — E: Floral bract. — F: Anther. — G, H: Gynostemium, various views. — I, J: Pollinium and viscidium (R. G. Tamayo del.). ANN. BOT. FENNICI 35 (1998) • A new definition of the genus Tamayorkis 25 Fig. 3. Tamayorkis hintonii (Todzia) R. Gonzalez & Szlach. (from Patterson 6133, TEX). — A: Habit. — B: Flower, front view. — C: Floral segments. — D: Anther. — E: Gynostemium. — F: Pollinium and viscidium, various views (R. G. Tamayo del.). 26 Tamayo & Szlachetko • ANN. BOT. FENNICI 35 (1998) Fig. 4. Tamayorkis wendtii (Salazar) R. Gonzalez & Szlach. (from Parranza 2680, IEB). — A: Habit. — B: Flower, side view. — C: Floral parts. — D: Floral bract. — E: Gynostemium. — F: Anther. — G: Pollinium and viscidium, various views (R. G. Tamayo del.). Curiously, Todzia (1993) compared her new species Malaxis hintonii with M. ehrenbergii, M. pringlei (S. Wats.) Ames, and M. tenuis (S. Wats.) Ames on the basis of their unifoliate habit, but the last two species each belong to a different group of Mexican Malaxis. Todzia did not men- tion either M. porphyrea Ridley or M. arachnifera S. Wats. When publishing M. wendtii, Salazar (1993) compared it with M. ehrenbergii and neglected to discuss the species mentioned in Ridley’s revision. Neither of the two authors mentioned Malaxis platyglossa (Rob. & Greenm.) ANN. BOT. FENNICI 35 (1998) • A new definition of the genus Tamayorkis Ames, as a species or as a variety of M. ehrenbergii (Williams 1950). In both cases the circumstantial evidence concerning the nomenclatural priority is heavy but the question can be solved only when the type specimens or drawings of them can be compared. Thus we consider Tamayorkis to comprise four of the species treated above. An additional note is necessary with respect to the treatment of Malaxis ehrenbergii var. platyglossa by Williams (1950). We think that reduction of M. platyglossa to a varietal status is unjustified since each species of Tamayorkis is consistent in its features without intermediate forms throughout its area of distribution, as are most of the species of Malaxis. We left discussion of Microcystis minutiflora Schltr. to the end of this paper because it has been reduced by authors to synonymy within Tamayorkis ehrenbergii. Schlechter (1899) stated that “flowers are green, the smallest in the genus (Microstylis), sepals and the lip 1 mm long, lip deltoid, acute or slightly acuminate, at the base auriculate hastate, at base inside provided with 2 minute, roundate calli”. Ames and Schweinfurth (1935) wrote “The type of Microstylis minutiflora shows a leaf which might be described as elliptic-oblong and is somewhat longer and narrower in proportion than is usually the case in Malaxis ehrenbergii. The flowers of Microstylis minutiflora, however, are in almost perfect agreement with those of M. ehrenbergii, although perhaps a trifle smaller”. 27 From these considerations, therefore, it appears to us that Microstylis minutiflora might be conspecific with Malaxis ehrenbergii. It still is possible that Microstylis minutiflora is an acceptable species after all, but without the chance of examining the type, we prefer just to mention the problem which does not affect the present redefinition of the genus Tamayorkis. Acknowledegments. We thank Dr. Carol Todzia for the opportunity to study some of her material and Dr. Jerzy Rzedowski for his permission to examine a specimen of Malaxis wendtii conserved at IEB. REFERENCES Ames, O. & Schweinfurth, C. 1935: Malaxis ehrenbergii (Rchb. f.) Kuntze — Bot. Mus. Leafl. Harvard Univ. 3: 116. Ridley, H. N. 1888: A revision of the genera Microstylis and Malaxis. — J. Linn. Soc. 24: 308–351. Salazar, G. 1993: Malaxis wendtii, a new orchid species from Coahuila and Nuevo Leon, Mexico. — Orquidea (Mex.) 13: 281–284. Schlechter, R. 1899: Microstylis minutiflora Schltr. — Bull. Herb. Boiss. 7: 540. Szlachetko, D. L. 1995: Systema Orchidalium. — Fragm. Flor. Geobot., Suppl. 3: 121–122. Todzen, T. K. 1995: Malaxis wendtii (Orchidaceae) in the United States. — Sida 16: 591. Todzia, C. 1993: Malaxis hintonii, a new species from Mexico. — Orquidea (Mex.) 13: 121–124. Williams, L. O. 1950: New and noteworthy orchids. — Ceiba 1: 187.