Ipomoea kahloiae Gonz.

González-Martínez, César Adrián, Lozada-Pérez, Lucio, Rios-Carrasco, Sandra, Alvarado-Cárdenas, Leonardo O., Martínez-González, César Ramiro, Castro-Lara, José Manuel & Jiménez-Ramírez, Jaime, 2018, Ipomoea kahloiae (Convolvulaceae), a noteworthy new species endemic to Guerrero, Mexico, Phytotaxa 356 (1), pp. 49-60 : 50-57

publication ID	https://doi.org/ 10.11646/phytotaxa.356.1.4
persistent identifier	https://treatment.plazi.org/id/B62A7A29-FFCC-FF8B-FF16-F9D6A7850204
treatment provided by	Felipe
scientific name	Ipomoea kahloiae Gonz.
status	sp. nov.

Treatment

Ipomoea kahloiae Gonz. -Martínez, Lozada-Pérez & Rios-Carrasco sp. nov. ( Figs. 1–4 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 )

Type:— MEXICO. Guerrero: Chilpancingo de los Bravo: a 2 km al sur del poblado de Acahuizotla, 807 m, 17°21’17.6’’ N, 99°27’27.4’’ W, 27 Aug. 2014 (fl.) C.A. González-Martínez & S. Rios-Carrasco 390 (holotype: FCME!, isotypes: ENCB!, FCME!, IEB!, MEXU!, XAL!).

Diagnosis:— Ipomoea kahloiae is distinguished by the presence of tri-winged stems, leaves with a winged petiole and midvein, subsessile inflorescences with foliose, obovate, mucronate, pinkish-green keeled bracteoles with a slightly oblique apex, an oblong, keeled calyx with a mucronate apex and white-pinkish sepals, a campanulate, magenta corolla above a short basal cylindrical tube which inside is white with pink dots and a whitish ring towards the limb.

Description:— Perennial climber( Fig. 3B View FIGURE 3 ); root woody,fibrous; stems 2‒5m long2.6–3(‒5) mm thick,herbaceous, slightly branched, sparsely puberulent, green, 3-winged, the wings 2‒3 mm wide ( Figs. 1B View FIGURE 1 , 3G View FIGURE 3 ), membranous, light green, slightly purple when mature; internodes 8.5‒14.5 cm long. Leaves petiolate, 11‒17.5(‒21) × 13‒19(‒27) cm, 5(‒7) palmatilobed, the base cordate, the lobes unequal, basal lobes 5.8‒13(‒15) × 2‒6 cm, elliptic, lateral lobes 9.2‒16.7(‒21.5) × 2.2‒7 cm, elliptic, central lobe 9.5‒19.8(‒22) × 3.2‒9 cm, obovate, membranous, margins entire, weakly revolute, the apex acuminate-mucronate, both surfaces puberulent with simple trichomes from a widened base, adaxially green, abaxially light green to whitish, venation actinodromous, the midvein abaxially winged, sparsely puberulent, green ( Figs. 1A View FIGURE 1 , 3C–D View FIGURE 3 ), petioles 5‒13.5 cm × 1‒2.2 mm, sulcate, puberulent, light green, winged, the wings ca. 0.4 mm wide, coriaceous when fresh, membranous when dry, light green to slightly purple. Inflorescences formed of axillary, dichasia; flowers (1‒)3‒6 ( Figs. 1A View FIGURE 1 , 2D View FIGURE 2 ), sweetly fragrant; peduncles 0.8‒1.1 cm, puberulent, green, weakly winged, not accrescent in fruit; bracteoles 1.5‒2.3 × 0.9‒1.3 cm, leaf-like, coriaceous, obovate, keeled, the margin entire, the base truncate, the apex weakly oblique, mucronate, exterior puberulent, pinkish-green, becoming pinkish ( Fig. 2G View FIGURE 2 ); secondary peduncles 3.2‒4.3 mm; pedicels 8 mm when flowering, thickened upwards in fruit; sepals equal, 21‒24 × 8.3‒10.8 mm, oblong, coriaceous, puberulent, the midvein slightly elevated on the outer side, margin entire, base truncate, apex obtuse and mucronate, the central part pinkish-white, the margin and apex whitishgreen ( Fig. 2H View FIGURE 2 ), persistent and partially enclosing the fruit ( Fig. 3E View FIGURE 3 ); corolla 6.5 cm long, campanulate above a narrow, cylindrical basal tube, exterior puberulent, white, becoming magenta upwards, the interior glabrous, with magenta spots and vertical lines, the basal cylindrical tube 1.5‒2 × 0.37‒0.43 cm, upper expanded part 3.7‒4 × 3‒3.5 cm, the limb 5.5‒6 cm wide, subentire, weakly 10‒lobed, the edges slightly reflexed, magenta, ( Figs. 1D View FIGURE 1 , 2A–F View FIGURE 2 ); stamens 1.8‒2.7 cm long, unequal, white, the base glandular-puberulent, adnate to the base of the corolla, anthers 6.4‒6.9 × 1.1‒1.4 mm, oblong, white ( Fig. 1D View FIGURE 1 ); pollen spherical, pantoporate, with reticulate exine, ornamented with spines, spinules and gemmae; pores with microspines and gemmae, without opercula ( Fig. 4 View FIGURE 4 ); style 3.8‒4 cm long, filiform, white, glabrous; stigma bilobed 1.2 × 2 mm, white; ovary 2 × 1.5 mm, partially enclosed within the nectary, puberulent. Capsules 1.4‒1.6 × 0.9‒1 cm, ellipsoid, woody, externally puberulent, dark brown, the base of the style persistent, ca. 0.4‒0.5 mm long, locules 2, 4‒valvate, dehiscent ( Figs. 1H View FIGURE 1 , 3E View FIGURE 3 ); seeds 4, 9.2‒9.6 × 4.6‒5 mm ellipsoid, the apex acute, the base apiculate, dark brown, minutely reticulate, glabrous except the copper-coloured marginal trichomes, which reach up to 8.5 mm long ( Figs. 1I View FIGURE 1 , 3F View FIGURE 3 ).

Etymology:— The specific epithet of this species honors the Mexican artist Frida Kahlo (1907–1954), one of the most influential Latin American artists of the 20th century. Frida Kahlo, besides being a painter, participated in many cultural, academic and political activities and was a social activist. Kahlo revived the roots of Mexican popular art and became a cultural reference point for the people of Mexico and its national identity.

Distribution and ecology:— Ipomoea kahloiae is restricted in its distribution and is known from only one population in the tropical semideciduous forests of the Acahuizotla region of Guerrero, Mexico ( Fig. 5 View FIGURE 5 ). The tropical semideciduous forests of the Acahuizotla region are of considerable floristic importance because of the great species richness they harbor.Acahuizotla represents a geographical center of endemism since eleven species are endemic to the region and its surroundings ( Jiménez-Ramírez et al. 2016). I. kahloiae is a scarce element of the understory and is only visible during the rainy season. It thrives at lower altitudes of “El Sombrerito” and “El Palmar” hills at an elevation of 800 m, where it mostly grows close to rivers in open humid places ( Fig. 3A View FIGURE 3 ). It is associated with species such as Dendropanax arboreus (L.) Decne. & Planch. ( Decaisne1854: 107) ( Araliaceae ); Enterolobium cyclocarpum (Jacq.) Griseb. ( Grisebach1860: 226) ( Fabaceae ); Coussapoa purpusii Standl. ( Standley1930: 6) ( Urticaceae ); Pseudobombax ellipticum (Kunth) Dugand (1943: 67) ( Malvaceae ); Swartzia simplex (Sw.) Spreng. ( Sprengel1825: 567) ( Fabaceae ); and Urera baccifera (L.) Gaudich. ex Wedd. ( Gaudichaud-Beaupré & Weddell1852: 199) ( Urticaceae ).

Additional specimens examined:— MEXICO. Guerrero: Chilpancingo de los Bravo: Acahuizotla , camino a la planta de luz, 800 m, 17°21’20” N, 99°27’17.7’’ W, 5 Oct. 2013 (fl, fr) L. Lozada 3588 & R. de Santiago (ENCB!, FCME!, IEB!, MEXU!, XAL!) GoogleMaps ; Chilpancingo de los Bravo : a 2 km al sur del poblado de Acahuizotla, 807 m, 17°21’17.6’’ N, 99°27’27.4’’ W, 23 May. 2015 (fr.) C.A. González-Martínez & S. Rios-Carrasco 957 (ENCB!, FCME!, IEB!, MEXU!, XAL!) GoogleMaps .); 3 Chilpancingo de los Bravo : a 2 km al sur del poblado de Acahuizotla, 807 m, 17°21’17.6’’ N, 99°27’27.4’’ W, 1 Jul. 2015 (fl.) C.A. González-Martínez & S. Rios-Carrasco 977 (ENCB!, FCME!, IEB!, MEXU!, XAL!) GoogleMaps .

Conservation status:— Among the main threats to the population of Ipomoea kahloiae are changes in land use, mainly for agricultural purposes, and regular disturbance of vegetation for the maintenance of electricity cables and the isolated felling of trees. The population consists of fewer than 20 individuals and is fragmented and prone to anthropogenic disturbance so this species should be categorized under category C2a(i) (Critically Endangered) of the IUCN Red List of Threatened Species ( IUCN 2017). To ensure its protection under Mexican regulations, it should be included in the list of endangered species under the category Endangered (P) of NOM-059-SEMARNAT-2010 ( SEMARNAT 2010).

Phenology:— Ipomoea kahloiae blooms at the height of the rainy season from August to October. Fruiting begins at the end of the rainy season in October and November and persists until May on dry plants. Flowering is staggered, with flowers maturing at different times on each inflorescence ( Fig. 2D View FIGURE 2 ). Flowers open very early in the morning and close at nightfall, the corolla detaching from the receptacle ( Fig. 2B–C View FIGURE 2 ). Orchid bees of the species Euglossa townsendi Cockerell and bumblebees of the genus Bombus have been observed visiting the flowers. In most of the fruits, the valves are separate but remain closed around the seeds although sometimes remaining united at the apex ( Figs. 1H View FIGURE 1 , 3E View FIGURE 3 ).

Comments:— Ipomoea kahloiae presents a novel combination of characters for the genus, which makes it difficult to relate morphologically to known species of the genus ( Figs. 2 View FIGURE 2 , 3 View FIGURE 3 ). However, molecular evidence suggests its inclusion within Ipomoea in the Astripomoeinae clade sensu Stefanović et al. (2003) ( Fig. 6 View FIGURE 6 ), to which belong most American species including I. arborescens (Humb. & Bonpl. ex Willd.) G. Don (1838: 267) , I. cuneifolia Meisn. ( Meisner 1869: 245) , I. carnea Jacq. ( Jacquin1760: 13) as well as the Asian I. sumatrana (Miq.) Ooststr. ( Ooststroom 1940: 571) ( Stefanović et al. 2003). The phylogenetic placement of the new species in Ipomoea will become clearer with increased sampling.

Bracteoles are considered a morphological character of great taxonomic importance in Ipomoea ( Austin et al. 2011) . This feature is the main attribute to distinguish I. kahloiae from all the other species of the genus. The species of Ipomoea mostly present linear, lanceolate bracteoles ( Austin 2001), but the new species presents foliose, obovate, notably keeled bracteoles with an oblique and mucronate apex ( Fig. 2G View FIGURE 2 ). It might be compared to I. bracteata Cav. ( Cavanilles1799: 51) but the bracteoles of I. bracteata are ovate, herbaceous, and pink. They wrap around the flowers, which are subhypocrateriform with exserted stamens ( McDonald 1994).