Habenaria ocadiziana

Peinado-Arellanes, Jesus Manuel, 2018, Habenaria ocadiziana (Habenariinae: Orchidaceae) a new and unusual species from western Mexico, Phytotaxa 334 (3), pp. 241-247 : 241-246

Habenaria ocadiziana J. M. Peinado-A, sp. nov. ( Fig. 1–3 )

This species is similar in overall the morphology to other species such as H. ofeliae R. González & Cuev. -Fig. in González & Hernández (2010:115) and Habenaria rosulifolia Espejo & López-Ferrari in García-Cruz et al. (2000: 32) by the leaves in a basal rosette, slender plant, bilobed petals, trilobed lip, long and parallel anther channels. It is distinct in the external lobe of the petal 1.5 to 2 times the length of the internal lobe, thin and filiform, also the lateral lobes of the lip are longer and filiform in comparison to the middle lobe, sharing this character with H. protusorostrata R. González & Cuev. -Fig. in González & Hernández (2010:117) and H. rzedowskii R González (1995:76) . However, it is different from the the latter two because the external lobes of the petals are erect above the dorsal sepal, the lip middle lobe linear-oblong, acute, sigmoid, incurved in natural position with margins reduplicate almost to the middle, and the spur, inflated and sigmoid in the apical portion, 16–17 mm long × 2 mm wide at apical portion. (see the key and Table 1).

Type:— MÉXICO. Jalisco: Tequila, on the fringes of the Nayarit State border, predio la Parida, pine-oak forest, location UTM 13 Q 622375 2351664, 2089 m, 4 October, 2016, J. M.Peinado -Arellanes 3032 & G. Ocadiz-López. (Holotype: IBUG!).

Plants slender, erect, inconspicuous, terrestrial, 15–19 cm tall including the inflorescence, when pressed the color changes to an olive-green; tuber spherical to subglobous. the tuber was drawn and lost afterward; leaves 8, 4 spiraled basal rosette, eliptical-cordiform 1.9–2 cm long, 1.3 cm wide, 5-veined, and 4 caulinars ovate-lanceolate to elipticallanceolate, 3-veined. Inflorescence raceme laxly 9.5–10.5 cm long, with 8–9 sub-secundus flowers, 1–1.5 cm wide; floral bract lanceolate to ovate-lanceolate, carinate, in the central vein, leaving the spur free; flowers bright green, point in same direction, ca 2 cm long × 1–1.5 cm wide; ovary glabrous with 3 keels; dorsal sepal suborbicularlanceolate, apiculate, 8–9 mm × 5–6 mm. with 3-veined, central vein has a dorsal keel; lateral sepals 9–10 × 3–4 mm wide, falcate, obliquely oblong-lanceolate, acute, 3-veined reticulate; petals bilobed, wide base, posterior lobe oblongtriangular, acute, oblique, slightly falcate, with a vein from the base to the apex, 5.5–6 mm × 2 mm, anterior lobe filiform, longer than posterior lobe, 11–13 mm (– 15 mm) long, erect above the dorsal sepal; lip trilobed, ungiculate, with a short narrow nail, 2 mm × 1 mm; pendant; the middle lobe linear-oblong, acute, sigmoid, incurved in natural position with margins reduplicate almost to the middle, 7 × 0.5 mm, descending lateral lobes, filiform, acute, 12 mm × 0.5 mm wide, longer than the middle lobe; spur descending, parallel and longer than the to the ovary, inflated and sigmoid in the apical portion, 16–17 mm long × 2mm wide at apical portion, longer than the middle lobe of the lip, fusiform-sigmoid, with a carina in the ventral part, 1 mm wide that fades towards the apex; column about 5 mm long, white-greenish, oblong to rectangular, semi-circular in lateral view, truncate to emarginate at the apex; stelidia ca. 1.5 mm long, ca. 1 mm wide, short, oblong, verrucose; rostellum ca. 2 mm high, thick, triangular-rounded with the anther channels incurved; stigmaticprocesses 1.8–2.2 mm long, 1–1.3 mm wide, green, short, oblong, anther bilocular, the anther cells parallel, oblique, elliptic, each one extending in a incurved channel, ca. 4 mm long; pollinia ca. 1.4 mm long, elliptic, oblique; viscidia reddish, hemispherical, in the apex of the anther channel. Fruit and seeds not seen.

Etymology:—The epithet is dedicated to Gregorio Ocadiz Lopez, who found the plant and noted the differences it has with other habenarias that inhabit the region, which correspond to Habenaria jaliscana Watson (1887: 455) .

Distribution and Ecology: —Found in an open pine-oak forest, rocky terrain, elevated and dense grassland, its hills are considerably steep with inclinations of 35° at an elevation of 2220 m. they tolerate the terrain’s disturbances and grow along side H. jaliscana , (fig. 4). they bloom from late September–October.

As Arditti (1992) mentions, the terrain provides soil that is soft and rich in organic nutrients at shallow depths, which allow its seeds to prosper and form colonies . This is probably the case of this species, considering it is a geophytes. The vegetation is congruent with that reported in Hágsater et al. (2005) and validates the ecological elements where these plants were found.

Identification key

1. Flowers with the spur shorter than the ovary ............................................................................................................... H. rzedowskii

- Flowers with the spur equal to or longer than the ovary...................................................................................................................2.

2. Petal with lobes of almost the same size, lip with lobes of almost the same size.............................................................................3.

- Petal lobes with different length, lip with lateral lobes more longer than middle one.......................................................................4

3. Plants 9–25 cm long, 3–6 flowers, 5–7 leaves, location Morelos and Estado de Mexico ............................................. H. rosulifolia

- Plants 21–35 cm long, 9–11 flowers, 8 leaves, location Zacatecas ...................................................................................... H. ofeliae

4. Plants 25 cm long, spur 20 mm long × 1.5mm wide, ovary 16 mm long × 1.5 mm diameter, rostellum projected in lateral view, lip with the middle lobe descendig........................................................................................................................ H. protusorostrata

- Plants 15–19 cm long, spur 17 mm long × 2mm wide, ovary 10 mm long × 2 mm diameter, rostellum inconspicuous in lateral view, lip with the middle lobe incurved ....................................................................................................................... H. ocadiziana

Comments: — Habenaria ocadiziana is distinguished from this complex of species by the petals lateral lobes erect above the dorsal sepal and the lip middle lobe incurved. These characteristics are unusual in the habenarias previously described. These species compose a morphological alliance that needs a phylogenetic study to increase the knowledge about this genus in Mexico.

Figures

FIGURE 1. Habenaria ocadiziana J. M. Peinado-A. A. Habit B. Flower, lateral veiw. C. Flower frontal veiw. D. Lip frontal veiw. E. Dorsal sepal and lateral sepals. F. Petals. G. Lip and Spur lateral view. H. column frontal view. I. column lateral view. J. lip frontal view. K. Flower view ¾. Draw from holotype by Jesus Manuel Peinado-Arellanes.

FIGURE 2. Habenaria ocadiziana in situ.

FIGURE 3. Habenaria ocadiziana flower close-up.