Koellensteinia Reichenbach (1854: 17)

Thiago E. C. Meneguzzo, José F. A. Baumgratz & Cássio Van Den Berg, 2015, Taxonomic studies in the Aganisia complex (Orchidaceae, Zygopetalinae), Phytotaxa 238 (1), pp. 1-39 : 15-16

3. Koellensteinia Reichenbach (1854: 17) .

Aganisia sect. Koellensteinia (Rchb.f.) Kuntze in von Post & Kuntze (1903: 13). Type: — Koellensteinia kellneriana Reichenbach (1854: 17)

Etymology:— Named after Captain Carlo Kellner von Köllenstein, Austrian orchidist who sent many specimens to Heinrich Gustav Reichenbach.

Terrestrial or epiphytic herbs, rarely rupiculous, sympodial growth, caespitose with thick, spongy roots. Flowering pseudobulbs inconspicuous, homoblastic, ovoid in transverse section; cataphylls basal, non-leafy, non-scarious, nonarticulate. Leaves 2–4 per pseudobulb, distal on pseudobulb; petiole conduplicate, distinct from blade, margin nonhyaline; blade articulate, plicate, narrowly ovate, narrowly elliptic, narrowly obovate or linear, base attenuate, apex acute, abaxial face with 3 prominent nerves. Inflorescences racemose or doubly racemose, lateral, axillary on inner cataphyll, erect or arching, pedunculate, longer than the plant, rarely shorter, rachis lax, rarely congested, blooming acropetally; bracts long-lanceolate, adpressed; bracteole 1, shorter than the ovary. Flowers resupinate, pedicellate. Dorsal sepal free, the laterals ones adnate to column feet and oblique, narrowly ovate, ovate or elliptic. Petals free, narrowly elliptic or elliptic. Lip free, motile, trilobed, unguiculate; midlobe elliptic, oblong or obtrapezoidal, apex rounded, obtuse or truncate, callus bilobed or rarely trilobed, retrorse; lateral lobes ovate or dolabriform, erectascending. Column semi-clavate, column foot shorter than the column, apex with inconspicuous stigmatic wings; anther incumbent, clinandrium projecting or not over the anther, margin entire or toothed, external face of anther cap bilobed, apex obtuse-denticulate, inner face bilocular; pollinia 4, in 2 pairs, juxtaposed, oblong-ovoid, laterally compressed, unequal in size and shape, tegula oblong, caudicle amorphous, sticky, viscidium ovate; stigma transverse; rostellum trilobed, median lobe narrowly triangular, lateral lobes reduced, not exceeding the stigma, rostellum remnant trilobed, median lobe acute and longer than the truncate laterals ones. Capsule fusiform, 6-carinate, surface verrucose; seeds not seen.

Distribution and habitat:— Koellensteinia is distributed in Belize, northern and western South America, and northern, northeastern, west central and eastern Brazil. Koellensteinia graminea is the most widespread species, commonly an epiphyte high above the soil under a dense canopy forest in Trinidad, northern, western, and disjunct in northeastern Brazil, from sea level to 1,000 m. Koellensteinia carraoënsis and K. lilijae are terrestrial species restricted to northern South America, the former from the Guyana Shield in floresta de terra firme (high canopy forest on nonflooding soil), up to 500 m above sea level, and the latter to Río Atabupo Basin in low vegetation on rocky outcrops about 100 m above sea level. Koellensteinia hyacinthoides and K. kellneriana are widespread in the Amazon Basin and Guiana Shield, the former as low-growing epiphytes or rupiculous, the latter as terrestrial, both in open sandy savannas or low density floresta de terra firme. Koellensteinia tricolor occurs in northern South America, always on left margin of the Amazon River, and also reaches Belize. Koellensteinia ionoptera is endemic to Peru in wet forest. Koellensteinia eburnea is a common species in campo úmido (moist grassland) in southeastern and west central Brazil and Bolivia. Koellensteinia florida is restricted to restinga in Bahia and Espírito Santo, northern and southeastern Brazil. Koellensteinia spiralis is endemic to coastal forests in Bahia, northern Brazil. TDWG code: 80 BLZ-OO 81 TRT-OO 80 BLZ-OO 82 FRG-OO GUY-OO SUR-OO VEN-OO 83 BOL-OO CLM-OO 84 BZC-DF BZC-GO BZC-MT BZC-MS BZE-BA BZL-ES BZL-MG BZN-AM BZN-AP BZN-PA BZN-RR.

Diagnostic characters:— The genus is distinguished by medium to large plants (35–150 cm tall), non-rhizomatose, inconspicuous pseudobulbs covered by non-leafy, non-articulate, and non-scarious cathaphylls, articulate leaves, petiole with non-hyaline margin, plicate, inflorescence taller than the leaves (sometimes shorter in Koellensteinia graminea ), lax rachis (only congested in K. florida ), medium-sized flowers (sepals up to 2 cm), trilobed lip, bilobed or trilobed retrosed callus, and column with inconspicuous stigmatic wings.

Generic delimitation:— The presence of Koellensteinia species in two distinct clades in the phylogenetic analysis of Whitten et al. (2005) could suggest that the genus is not monophyletic. However, at this moment the analysis of morphological characters shows it to be homogeneous, and the absence of obvious discontinuity at first does not support this ambiguous result. A more thoroughly sampled analysis is desirable.

Key to the species of Koellensteinia

1 Lip midlobe with obtuse apex ............................................................................................................................................................2

- Lip midlobe with rounded or truncate apex .......................................................................................................................................6

2 Leaves blade linear and narrow (up to 0.5 cm large) ....................................................................................................... K. graminea

- Leaves blade elliptic and large (more than 1 cm large)......................................................................................................................3

3 Rachis congested .................................................................................................................................................................. K. florida

- Rachis lax ...........................................................................................................................................................................................4

4 Lip lateral lobes with erose margin ........................................................................................................................... K. hyacinthoides

- Lip lateral lobes with entire margin....................................................................................................................................................5

5 Petals with distal margin entire .................................................................................................................................... K. carraoënsis

- Petals with distal margin slightly erose .............................................................................................................................. K. dasilvae

6 Inflorescences spiral ............................................................................................................................................................ K. spiralis

- Inflorescences non-spiral....................................................................................................................................................................7

7 Lip midlobe narrower than length between lateral lobes ................................................................................................... K. eburnea

- Lip midlobe width equal or subequal to length between lateral lobes ...............................................................................................8

8 Lip midlobe longer than lateral lobes in length...................................................................................................................... K. lilijae

- Lip midlobe equal or subequal to lateral lobes in length....................................................................................................................9

9 Lip lateral lobes oblong................................................................................................................................................... K. ionoptera

- Lip lateral lobes semi-orbicular........................................................................................................................................................10

10 Lip lateral lobes overlapping median lobe .................................................................................................................... K. kellneriana

- Lip lateral lobes not overlapping median lobe .................................................................................................................... K. tricolor