Neomillspaughia hondurensis Ortiz-Díaz & Arnelas, 2013

Ortiz-Díaz, Juan Javier, Arnelas, Itziar, Tun, Juan & Flores, José Salvador, 2013, Neomillspaughia hondurensis (Polygonaceae), a new species from Central America, Phytotaxa 144 (1), pp. 56-60 : 57-58

Neomillspaughia hondurensis Ortiz-Díaz & Arnelas , sp. nov. ( Fig. 1C–D )

Type:— HONDURAS. Francisco Morazán: Vicinity of Suyapa , region of La Travesía, municipio del Distrito Central, 1100-1200 m., open rocky brushy hillside, September to December 1948, Paul C . Standley 12421 (holotype EAP!) .

Diagnosis: — Neomillspaughia emarginata similis sed foliis apice obtusis vel emarginatis, inflorescentiis minoribus, perianthium fructiferum et achaenium longioribus et latioribus.

Description: —Shrub 1–4 m tall. Internodes 30–45 × 2–3.5 mm, geniculate, articulate, striated, lenticeled, glabrous or scabrous, brownish. Ocreae deciduous, 2–4 mm long. Leaves simple, alternate, with a petiole 2.0– 3.0 × 0.1–0.2 cm, scabrous, striated. Leaf blade broadly ovate-lanceolate to orbicular, 8–12 × 8–10 cm, subcoriaceous, margins revolute, obtuse or emarginate at the apex (10–16 mm), cordate at the base, scabrous above on primary and secondary veins, densely scabrous beneath on the primary and secondary veins, sparsely glandular–punctate, reticulate venation with 6–8 primary veins, primary and secondary venation prominent beneath, brown above, lighter beneath when dry. Inflorescence lax and reduced panicle with 1–3 racemes, terminal, solitary or in pairs, 7–13 × 2–7 cm in fruit; rachis striate, puberulent, 0.8–1.3 mm width, not well differentiated; bracteole chartaceous, acuminate, 1 − 3 mm long, puberulent; ocreolae membranous, glabrous. Flowers hermaphroditic, in fascicles of 2–6 within ocreolae, perianth petaloid at anthesis, tepals 5, membranaceous in two whorls, the 3 outer segments ovate, acuminate at apex, slightly scabrous in the inner margin, winged, 2 inner ovate–lanceolate, 3.5–4.0 × 1.7 mm in fruit, 5-nerved, sparsely glandular and scabrous. Stamens 8–9, 2.0− 2.5 mm long, united at base for 0.2−0.3 mm, pubescent at base on the dorsal surface, anthers suborbicular, 0.3–0.5 mm long, dehiscence longitudinal. Ovary superior, sessile, trigonous, unicarpelar, unilocular, glabrous, styles 3, stigma 3, capitate, ovule 1, basal. Fruit achene, trigonous, 4.0–5.5 × 2.5–3.5 mm, dark brown, lustrous, styles persistent, perianth accrescent and dry in fruit, 10–14 × 5–6 mm, pale when dry. Seed trigonous, endosperm not ruminate, embryo subcentral, straight, cotyledons suborbicular.

Distribution and ecology: — N. hondurensis is only known from few localities from central Honduras in Francisco Morazán department ( Fig. 2 ). This species was collected on soils derived from limestone substrate, basalt and andesite in open rocky brushy hillsides, in moist montane pine forest, between 1100−1300 m a.s.l. Flowering and fruiting is from July to December.

Taxonomical notes ( Fig. 1 , Table 1):— N. hondurensis is morphologically more related to N. emarginata than to N. paniculata . The first and the second species resemble each other by having small petioles, leaf blades, as well as by its big perianth. N. hondurensis differs from N. emarginata by having obtuse leaf blades (also emarginate), smaller inflorescences, as well as by its bigger perianth, and fruit. On the other hand, N. paniculata differs from the new species by having bigger leaves, and inflorescences, as well as a smaller perianth, and fruit. Moreover, N. hondurensis has a different ecology, and geographical distribution: growing in open rocky brushy hillsides in moist montane pine forest of central Honduras at high altitudes (1100-1300 m a.s.l.), while N. emarginata grows in tropical deciduous forest in lowlands of Yucatan Peninsula ( Mexico), Belize and Guatemala from 2 to 260 m a.s.l. ( Fig. 2 ). N. paniculata mainly inhabits xerophytic regions of the Comayagua valley ( Honduras), in gallery forest and rocky hillsides along river banks from 300 to 600(-900) m a.s.l., and extent its distribution to Southern Guatemala and Nicaragua ( Fig. 2 ). Several specimens with inmature inflorescences collected in subtropical thorny woodland from South Guatemala between km 40 and 45 on road to Zacapa, Chile, (see the specimina visa), which have been identified as N. emarginata or N. paniculata do not seem to belong to N. hondurensis , neither to N. paniculata nor N. emarginata . Additional collections with fully developed inflorescences are needed in order to determine whether plants from this population belong to one of the three described species or they belong to a new species.

Etymology: —The specific epithet is related to the country of type locality.

IUCN Red list category: —There is no available data on abundance or distribution of N. hondurensis , and make a direct or indirect risk assessment of the species is impossible. It is recommended that N. hondurensis should be included in the Data Deficient (DD) category of the UICN Red List (UICN, 2010).

Additional specimens examined: — HONDURAS. Francisco Morazán: Distrito Central, along road to Olancha, c. 2 mi NE of Tegucigalpa , 06 July 1962, Grady et al. s.n. ( MO) ; ibidem, La Travesía, 18 September 1948, Molina 1125 ( BM, EAP) . Santa Ana, Cerro de Hule , 20 km South of Tegucigalpa, 15 December 1975, Molina et al. 31171 ( EAP, MO) .

Figures

FIGURE 1. View of inflorescence and perianth of N. emarginata (A−B: Balam 94 EAP; Cabrera & Cabrera 14344 MO), N. hondurensis (C−D: Standley 12421 EAP; Molina et al. 31171 MO) and N. paniculata (E−F: Molina 22074 EAP; Nelson et al. 7037 MO). Scale 1 mm (B, D, F).

FIGURE 2. Distribution map of N. emarginata (white circle), N. hondurensis (black circle) and N. paniculata (triangle).