Habenaria sect. Microdactylae Kränzlin (1892: 100)

Batista, João A. N., Reis, André F. De S., Leite Junior, Josefran L. & Bianchetti, Luciano De Bem, 2018, Phylogeny and taxonomy of Habenaria leprieurii, H. alpestris and H. sect. Microdactylae (Orchidaceae), with descriptions of two new taxa, Phytotaxa 373 (4), pp. 241-271 : 246-247

Habenaria sect. Microdactylae Kränzlin (1892: 100) .

Type:— Habenaria leprieurii Rchb.f. , designated here.

Plants caulescent, small, slender. Leaves linear, appressed to the stem, largest in the median region of the stem, length to width ratio 10:1–44:1. Inflorescence short, lax, 0.7–1.5 flowers/cm of inflorescence, congested in H. heptadactyla , 2.1–4.9 flowers/cm of inflorescence. Flowers 2–30, small, corolla green, white, or yellow, pedicel shorter than the ovary. Dorsal sepal 2.5–6.5 × 2.0– 4.5 mm. Petals bipartite, anterior segment (0.4–)0.7–1.1(–1.7) times as long as the posterior segment. Lip tripartite, lateral segments (0.5–)0.7–1.0(–1.2) times as long as the median segment. Spur 6–27 mm long, 0.5–1.3 times as long as the pedicellate ovary. Stigmatophores closely parallel. Rostellum mid-lobe placed between the anther loci. Viscidia ellipsoidal, united.

Species included:— Habenaria cruegeri Cogn. , Habenaria cruegeri var. flaviflora J.A.N.Bat. & Bianch. , Habenaria heptadactyla Rchb.f. , Habenaria leprieurii Rchb.f. , Habenaria omissa J.A.N.Bat. & Bianch.

Notes:—A small section composed of four species, widespread from Panama to northern South America ( Colombia, Venezuela, Trinidad, Guyana, Suriname, French Guiana), Brazil (AM, AP, BA, DF, GO, MA, MG, MS, MT, PA, PB, PR, RN, RR, SP, TO), Bolivia, and Paraguay. Encountered in dry, seasonally or permanently humid grasslands, from sea level to 1,500 m a.s.l. Distinctive features of the section include leaves reduced, linear, appressed to the stem, flowers small, corolla white, green, or yellow, lateral segments shorter or approximately the same size as the main segment, and viscidia united. In terms of flower morphology, the section is quite similar to the species in subclade 15 ( Fig. 1 ) formed by H. alpestris (= H. melanopoda ), H. balansae Cogniaux (1906: 271) , H. itatiayae Schlechter (1930: 298) , and H. mello-barretoi Brade & Pabst (1967: 212) . No synapomorphies are known for any of the two clades, and their separation is based on a set of characteristics: the species in subclade 15 always have green flowers, H. alpestris and H. itatiayae have more developed and broader, subpatent leaves, H. mello-barretoi has lanceolate, basal leaves, while the pedicel of H. balansae is longer than the ovary and sharply curved. The pedicels of all of the species in subclade 15 are about the same size or longer than the pedicellate ovary, while the only species in H. sect. Microdactylae that has a well-developed pedicel is H. leprieurii , but it has a white corolla.

Figures

FIGURE 1. Bayesian 50% majority-rule consensus tree of the combined ITS and matK datasets. Numbers next to the nodes represent the posterior probabilities (PP) from the Bayesian analysis and bootstrap percentages (BS) from parsimony analyses. Only values of major clades are shown. Bootstrap percentages ≤ 50% are indicated by a dash (-). Neotropical subgroups are numbered according to Batista et al. (2013).