Capparidastrum dugandii

Mercado-Gómez, Jorge D. & Morales-Puentes, María Eugenia, 2020, A new species of Capparidastrum (Capparaceae Juss.) from the Cauca inter Andean valley of Colombia, Phytotaxa 439 (3), pp. 276-286 : 280-282

Capparidastrum dugandii Mercado-Gómez-J & M. E. Morales-P., sp. nov. ( Fig. 2 )

Type:— COLOMBIA: Antioquia, Santa Fe de Antioquia, La Carbajal Creek , El Espinal vereda, farm of Don Jorge Issacs , 3 km from the center of the town, via the Tunel Juan Blanco, 6°32’19,00”N, 75°51’26.08”W, 709 m, 25 February 2017, Mercado y Zapata D. 1122 (holotype and Isotype HEUS !) and one duplicated to be distributed in UPTC! ( Fig. 3a and 3c ).

Diagnosis:— Differs from another Capparidastrum subgenera Pulviniglans species by having the following morphological characteristic: 8 lateral veins; sepals with margin slightly denticulate, a lesser number of stamens (≤ 20), pinkish at the base. Gynophore pinkish at the base, fruits pepos oblongoid to subcylindric. In addition, this species is endemic to the tropical dry forest at the Cauca province ( Morrone 2014).

Treelet or tree to 6 m tall ( PLATE 1a ), glabrous throughout, with elongate, very abundant, protruding lenticels ca. 0.2–2.3 × 0.3 mm. Leaves evergreen, simple, spirally disposed ( PLATE 1b ), with pairs of small triangular stipules ca. 1–1.6 × 0.6–1 mm, petioles terete, basally canaliculated at the base of the blades on terminal new leaves, glabrous, of unequal length, shorter 1.1–2.1 cm and longer 4.5–7 cm, pulvinus in both sides 0.5–1 cm long, dark brown to blackish. Blades coriaceous, oval to elliptic 7.5–22 × 7.4–14 cm; base obtuse, unequal or rounded; apex retuse, emarginate, mucronate and acute, dark green above, pale green beneath, with 8 (9 on larger leaves) pairs of lateral nerves. Inflorescences with erect terminal racemes; relatively short peduncles 3–3.5 cm long; rachis terete, glabrous with 15–25 flowers ( PLATE 1c ), subtended by a pair of floral triangular bracts and deciduous ca. 1.8 × 1.6 mm, with a linear to triangular stipules in both sides ca. 0.9 × 0.3 mm; pedicels 1.8–2.5 cm long, strongly ascendant, terete and glabrous. Actinomorphic and hermaphroditic flowers, with 4 sepals and petals. Greenish to yellowish sepals, with open aestivation, broadly deltoid 0.5 × 0.6 cm; acute apex, entire margin to slightly denticulate; ascendant before at the anthesis, sepals reflexed at anthesis by the floral nectaries, glabrous. Floral nectaries, 4, episepals glands, yellowish site adaxially on the sepal base, fleshy, bulbous and sub-triangular 4 × 7 mm ( PLATE 1e and 1f ). White petals inside, outside green to whitish with a middle green shadow, ascending with imbricate aestivation, ovate 1.8–2 × 0.8–1 cm; apex rounded; spatular to truncate at the base. Stamens 18–20, filaments exserted of 44–60 mm long, glabrous, pinkish at the base, anthers fixed on the dorsum 3–3.5 mm long, yellow to whitish, longitudinally dehiscence ( PLATE 1d ). Gynophore exserted of 70–72 mm long, glabrous, pinkish throughout; ovary oblongoid to cylindric 5 × 2 mm, green to yellow in the mature state. Fleshy fruits, pepos oblongoid to subcylindric 5.1–5.3 × 2.7–2.8 cm, with 4-week longitudinal placental lines or ribs, exocarp slightly verrucated ca. 1.6 mm thick, green immature and yellow mature ( PLATE 2a ); gynophore of ca. 8–8.1 long, pedicel 3.8 cm long (fruiting material), soft and white mesocarp. Seeds 25, orbicular to oblongoid 6.6–7.2 × 6.6–7.2 mm of diameter, cover by a black seed coat and white fleshy sarcotesta ( PLATE 2b ).

Additional specimen examined (paratypes): — COLOMBIA. Valle del Cauca, Dagua municipality, corregimiento of Atuncela . 3°44’14.92”N, 76°41’10.15”W, 1100 m, 24–28 August 1998, Vargas G.W. 4988 ( HUA!) ( Fig. 3c ). Antioquia, municipality of de Santa Fe de Antioquia, La Carbajal Creek , el Espinal vereda, farm of Don Jorge Issacs , 3 km from the center of the municipality, via the Juan Blanco Tunel. 6°32’19,00”N, 75°51’26.08”W, 709 m, 10 April 2013, Zapata D, et al. 70 ( COL!, JAUM!) ; Antioquia, municipality of Briceño, Tenche watershed , right bank of the Cauca River, close to the mouth of the Ituango River , 7°7’36.59”N, 75°39’48.88”W, 280 m, 19 July 2012, Zapata D, et al. 26 ( JAUM!) . Valle del Cauca, municipality of Dagua, Atuncela corregimiento, la Bocatoma sector ( Fig. 3b ), 300–400 m, 9 July, 2010, Vargas GW, 22120 ( ICESI!) .

Etymology: —Specific epithet refers to Armando Dugand. Armando Dugand was a pioneer in the taxonomy and the knowledge of the family Capparaceae for the flora of Colombia. He described and identified several species such as C. cuatrecasanum etc. Also, he performed a synopsis of Capparis s.l for Colombia and also contributed to the Caribbean floristic study.

Ecology and Distribution ( Fig. 3a–c ):— Capparidastrum dugandii is only known from three sites from the Dagua (Valle del Cauca; Fig. 3b ) and Cauca river valleys (Antioquia; Fig. 3c ), in the “cordillera Occidental” and in the middle of both “cordillera Occidental” and “cordillera Oriental” throughout 200–1200 m of elevation. The type was found in the Santa Fe de Antioquia municipality (Antioquia – Colombia) and the paratype near the 52 km mark on the road of Cali–Buenaventura. Both sites according to the life zone classification system of Holdridge (1947) belongs to tropical dry forest. Banda et al. (2016) defines this ecosystem as “having a closed canopy, distinguishing it from more open, grass–rich savanna. It occurs on fertile soils where the rainfall is less than ~ 1800 mm per year, with a period of 3 to 6 months receiving less than 100 mm per month ( Murphy & Lugo 1986, Sánchez-Azofeifa et al. 2005), throughout which the vegetation is mostly deciduous”. Identification of this new species of Capparaceae supports the hypothesis of different authors ( Cornejo & Iltis 2012, Pizano et al. 2014) who describe this family as mainly occurring in this ecosystem, endemic and possibly influenced by the climatic constraints of this ecosystem ( Mercado Gómez & Escalante 2018).

Regarding the pollination system, we did not record observations of potential visitors. However, although we observed ants around nectaries ( PLATE 1e ) that could perform a protective function more than pollination. The mature fruits (yellow) are edible, the mesocarp is soft, white and sweet, and some birds consume it (field observations by Andrés Caro). We propose birds as possible seed dispersers.

Phenology:— According to field observations and herbarium specimens, flowering is from the end of January to April; while fruiting is from March to April.

Conservation Status: — Capparidastrum dugandii is only known just from three collections in tropical dry forest of the Dagua river enclave near the Cauca River. Tropical dry forest in Colombia is a biome widely fragmented and found from the Caribbean, in inter-Andean valleys and other small forest fragments ( García et al. 2014). This is one of the most threatened forests in Colombia because of human disturbance. Conservation status is critical for this forest. In 1993, it was estimated that only the 1.5% of the original forest had disappeared ( Etter et al. 2008) and in 2008 less than 8 882 854 ha. Remained, within which 34.23% were being used for pasture, 28.25% for crops, 15.02% other uses and only 22.50% of its original extent still remained in Colombia ( García et al. 2014). We assigned the species provisionally as CR (Critically Endangered) in the IUCN conservation status (IUCN 2014).

Figures

PLATE 1. Examples of Capparidastrum dugandii (Mercado JD & Zapata D, 1122 HEUS!). (a) Growing over a slope. (b) Inflorescence exceeding foliage. (c) Inflorescence with floral button. (d) Detached flower at anthesis (above) and after postanthesis (below). (e) Nectary glands and base of gynophore after postanthesis, lateral view and (f) nectary glands, adaxial view.

FIGURE 2. (a) Branch with inflorescence. (b) Juvenile inflorescence. (c) Open flower with sepals, petals, stamens and style. (d) Flower detail of sepals. (f) Petals. (g) Fruit. (g) Fruit detail in longitudinal cut (scale: 1 a–g= 1cm; Mercado JD and Zapata D, 1122 HEUS!).

PLATE 2. (a) Infructescence and (b) sectioned fruit.

FIGURE 3. (a) Distribution map of Capparidastrum subgen. Pulviniglans species in Colombia. C. dugandii in (b) in Atuncela (river Dagua) and (c) Briceño and Santa Fe de Antioquia.