Research Article |
Corresponding author: Andres Ernesto Ortiz-Rodriguez ( ortizrodriguez.ae@gmail.com ) Academic editor: Alan Paton
© 2016 Andres Ernesto Ortiz-Rodriguez, Carlos Manuel Burelo Ramos, Héctor Gomez-Dominguez.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Ortiz-Rodriguez AE, Ramos CMB, Gomez-Dominguez H (2016) A new species of Amphitecna (Bignoniaceae) endemic to Chiapas, Mexico. PhytoKeys 65: 15-23. https://doi.org/10.3897/phytokeys.65.8454
|
Amphitecna loreae Ortiz-Rodr. & Burelo, sp. nov. (Bignoniaceae), a new species endemic to the karst rainforest in southern Mexico, is described and illustrated. The new species differs from the other species of Amphitecna by the combination of cauliflorous inflorescences, larger flowers, buds rounded at apex, and globose-ellipsoid rather than acuminate fruits. A key to the Mexican species of Amphitecna is presented.
Crescentieae , karst forest, zona sujeta a protección ecológica “La Pera”
Bignoniaceae (calabash tree family) includes about 82 genera and approximately 900 species of trees, shrubs and woody vines distributed mainly in tropical areas around the world (
The Crescentiina clade contains approximately 34 genera and 300 species, and it is formed by two subclades corresponding to the Tabebuia alliance and the Paleotropical clade (a group of genera traditionally assigned to Tecomeae and Coleeae) (
The genus Amphitecna is easily differentiated from Crecentia and Parmentiera by the combination of simple, alternate leaves and the greenish flowers with the lobes of the petals fused (
During the course of several botanical explorations in southern Mexico, a species of Amphitecna with a unique combination of features differing from all other members of the genus was collected in a karst forest of Chiapas. In this paper, this interesting species is described and illustrated and its affinities with other species of Amphitecna are discussed. Furthermore a key to Mexican species of Amphitecna is presented.
In order to confirm the status of this new species we visited and reviewed the specimens of Amphitecna deposited in herbaria
We assessed the conservation status by calculating the extent of occurrence (EOO) and the area of occupancy (AOO) using the GeoCAT tool (
Additionally, coordinates of occurrence data were assembled for the new species herein described and for the morphologically similar species, which were obtained from the Global Biodiversity Information Facility (GBIF; http://www.gbif.org/species/4003073), supplemented with records from field collection and with information available in the herbarium specimens. Then climate layers were obtained at a 30 arc-sec (c. 1 km2) resolution from the WorldClim database (
Mexico. Chiapas, Municipio de Berriozábal, zona sujeta a protección ecológica “La Pera”, predio “Peña Flor” camino Berriozábal- Vista Hermosa-El Cairo, km. 12 desvío al Pozo Turipache, 1068 m, 16°51'50.6"N, 93°19'51.7"W, 05 March 2012 (fl, fr) Ortiz-Rodríguez A. E 0178 (holotype
Amphitecna loreae is distinguishable from the other species of Amphitecna by a combination of its cauliflorous inflorescences, large flowers, buds rounded at apex, and broadly elliptical to spherical rather than acuminate fruits. Amphitecna tuxtlensis, A. montana and A. latifolia, also distributed in Mexico, have affinities with A. loreae and share the cauliflorous inflorescences and leaves less than 50 cm long. However, A. tuxtlensis differs in having the flower buds pointed at the apex and fruits elliptic, acute to acuminate at apex, and A. montana differs in having larger leaves, long pedicellate flowers and elliptical fruits shortly pointed at the tip, while A. latifolia differs in having obovate to widely elliptic leaves, rounded to mucronate at apex with poorly defined petioles (Figure
Trees, 15–25 m and 15–50 cm DBH, the secondary branches terete. Leaves, alternate-verticillate, clustered near the apex of the branches, olive-green when dry, glabrous, 10–20 cm long, 2–5 cm wide, oblanceolate to narrowly elliptic, acuminate, subcoriaceous, acute to attenuate basis, midrib slightly raised on the upper surface, prominent on the lower surface; secondary veins 11–14 on a side, slightly raised above, prominent below; petiole short, to 2 cm long, merging with attenuate leaf base. Inflorescences, groups of two or three flowers, with an unpleasant odor, which are borne on leafless portions of old branches and along the main trunk (cauliflory). Flower buds, rounded at apex. Flowers pendant, pedicel 35–60 mm long; calyx campanulate, 28–38 mm long, more or less coriaceous, evenly 2 to 3-labiate to below the middle, circumscissile; corolla radially symmetric, pale green, tubular-infundibuliform, 48–60 mm long, 30–40 mm wide at the mouth of the tube, the basal part of the corolla a straight tube, 15–25 mm long, the lobes fused in to frilly-margined rim; stamens included, inserted 18–28 mm from base of the tube, the anther thecae divergent, 4–7 mm long, the filaments 18–30 mm long; the staminode, when present, less than 20 mm long, inserted 10–20 mm from base of the tube, sometimes well developed (with one or two small thecae) to give the impression of being a fifth stamen; ovary, up to 3 mm long and 2.5 mm wide, broadly elliptical, glandular-papillose; pistil 40–60 mm long with the stigma bifurcate; disc annular-pulvinate, about 6 mm in diameter; flowers are often found with signs of herbivory, in which the ovule and disc are not present. Fruits broadly elliptical to spherical, 70–100 mm long, 60–80 mm wide.
The species is only known from Chiapas, Mexico. It is a rare species at the type locality in the ecological reserve La Pera. The species inhabits the karst areas, mainly in the tropical rainforest. It is a canopy tree and coexists with species of Quercus lancifolia Schltdl. & Cham., Q. corrugata Hook., Calatola costaricensis Standl., Spathacanthus hahnianus Baill, and Quararibea funebris (La Llave) Vischer.
Mature flowers and fruits were collected in March and April; buds, ripe and immature fruits were observed in the same months.
The specific epithet honors Francisco Lorea Hernández, in recognition of his many important contributions to our knowledge of the Mexican flora.
Currently we lack the necessary information to objectively define the conservation status of Amphitecna loreae. However, according to the criteria established by the IUCN, it is possible to tentatively determine that the species is Critically Endangered [CR B1ab (iii)]. Although the only known population of the species is located within a protected natural area, A. loreae appears to be rare ecologically and only eight individuals in one hectare of sampling were recorded (
Mexico. Chiapas, Berriozabal: Rancho “El Retiro”, atrás de el rancho “El Zapote”. 13 km al N de Berriozábal camino a Joaquín Miguel Gutiérrez, 16°52'09.2"N, 93°19'26.4"W, 1114 m., 04 May 2014, M. A. Escobar Castellanos 586 (
Amphitecna loreae sp. nov. has a combination of characters that clearly separate it from other species of Amphitecna : its strictly cauliflorous inflorescences distinguish it from those species with terminal inflorescences (Amphitecna apiculata A.H. Gentry, Amphitecna breedlovei A.H. Gentry, Amphitecna donnell-smithii (Sprague) L.O. Williams, Amphitecna isthmica (A.H. Gentry) A.H. Gentry, Amphitecna molinae L.O. Williams and Amphitecna steyermarkii (A.H. Gentry) A.H. Gentry).
The four cauliferous species discussed in the diagnoses have different distribution ranges with different climatic preferences (Figure
Distribution range and climatic preferences of Amphitecna loreae and related species. Amphitecna latifolia (purple circles) Amphitecna montana (green cross), Amphitecna loreae (black dots) and Amphitecna tuxtlensis (blue squares). In colours similar to those of the species the 95% confidence ellipses produced by PCA analysis.
Comparison of diagnostic morphological characters of Amphitecna loreae with its close relatives.
Characters | Amphitecna latifolia | Amphitecna montana | A. tuxtlensis | Amphitecna loreae |
---|---|---|---|---|
Habit | Tree to 10 m tall | Large tree, 10-20 m tall | Tree, 5-15 m tall | Large tree, 10-25 m tall |
Leaf length | to 19 cm | to 34 cm | to 18 cm | to 20 cm |
Leaf width | to 11 cm | to 11 cm | to 5 cm | to 5 cm |
Petiole | poorly defined | clearly differentiated | defined | defined |
Leaf shape | Broadly obovate | Oblanceolate to narrowly obovate | Oblanceolate | Oblanceolate |
Leaf apex | rounded to acute, usually apiculate | acute to short-acuminate | acuminate | acuminate |
Length of the flower pedicel | to 36 mm | to 100 mm | to 26 mm | to 60 mm |
Tip of flower buds | rounded | rounded | Pointed | rounded |
Fruit shape | broadly elliptical to spherical | Oblong-ovoid or ellipsoid | ellipsoid | broadly elliptical to spherical |
Fruit apex | rounded (rare shortly pointed) | shortly pointed to acute | acute to acuminate | rounded |
Habitat | always near sea level, mostly in mangrove associations and flooded vegetation | Mountain cloud forest | Tropical rain forest | Tropical rain forest |
Distribution | Mexico (Campeche, Tabasco, Veracruz and Yucatan); Central America, West Indies to Venezuela and Ecuador | Mexico (Chiapas); Guatemala | Mexico (Veracruz and Oaxaca) | Mexico (Chiapas) |
1 | Terminal inflorescences | 2 |
– | Cauliflorous inflorescences (borne on leafless portions of old branches and along the main trunk) | 5 |
2 | Calyx spathaceous with a sharp acumen | A. steyermarkii |
– | Calyx bilabiate or trilabiate | 3 |
3 | Corolla tubular less than 1 cm wide at the mouth of tube | A. apiculata |
– | Corolla campanulate more than 1 cm wide at the mouth of tube | 4 |
4 | Leaves membranaceous; corolla less than 3 cm long | A. donnell-smithii |
– | Leaves chartaceous to coriaceous; corolla more than 3 cm long | A. breedlovei |
5 | Leaves mostly 50–100 cm long, clustered near tip of twigs; small trees, 2–7 m, simple or few branched stem | 6 |
– | Leaves less than 40 cm long, alternate; medium and large sized trees,10–25 m, branched | 7 |
6 | Corolla less than 2 cm wide at the mouth of tube; pedicels to 4 cm long | A. macrophylla |
– | Corolla more than 2 cm wide at the mouth of tube; pedicels to 1 cm long | A. regalis |
7 | Fruits ovoid to narrowly oblong-ellipsoid, apiculate at apex | 8 |
– | Fruits ellipsoid to spherical, rounded at apex or very inconspicuously apiculate | 9 |
8 | Secondary venation impressed below leaves and conspicuously whitish-margined; petiole poorly demarcated, to 1 cm long; flower buds rounded to shortly pointed | A. silvicola |
– | Secondary venation prominent below leaves; and not whitish-margined; petiole 1–2 cm long; flower buds pointed | A. tuxtlensis |
9 | Trees to 10 m tall; leaves obovate to wide elliptic, rounded to mucronate at apex with poorly defined petioles; restricted to coastal ecosystems | A. latifolia |
– | Large trees, to 25 m tall; leaves oblanceolate to narrowly obovate, acute to acuminate at apex with defined petioles; tropical rain forest or cloud forest | 10 |
10 | Leaves, 34 ×11 cm; petiole to 4 cm long; pedicels to 10 cm long; forests above 1200 m | A. montana |
– | Leaves, 20 ×5 cm; petiole short, less than 2 cm; pedicels to 6 cm long; forests below 1000 m | A. loreae |
We extend our sincere gratitude to Yuyini Licona Vera, Miguel Ángel Pérez Farrera and Ruben Martínez Camilo for support during the preparation of the manuscript, Luiz Henrique Fonseca, Lulu Rico Arce and Alan Paton for reviewing and providing many useful comments on the manuscript, and particularly to Marcos Escobar for providing the excellent pictures of A. loreae.