Coulteria lewisiae Sotuyo S. & Contreras J.L., 2021

Sotuyo, Solange & Contreras-Jiménez, José Luis, 2021, Coulteria lewisiae (Leguminosae: Caesalpinioideae) a new species for Infiernillo region, Mexico, Phytotaxa 498 (3), pp. 220-226 : 220-225

Diagnosis: — Coulteria lewisiae Sotuyo S. & Contreras J.L. sp. nov. ( Fig 1 — 2 ).

Type:— México, Guerrero Municipio de Zirándaro: 3 km al O del Guariche , 21 September 1989, alt ca. 240 m, J.L. Contreras 25358 [fr] (Holotype: FCME ; Isotypes FCME , MEXU ).

Coulteria lewisiae is similar to C. platyloba but can easily differentiated from other species of the genus ( Table 1 ) in the size of the flowers of approximately 2 cm in length plus the calyx tube. A sericeous indumentum of the young leaves that changes to tomentose when mature, as well as a glabrous fruit.

Dioecious trees, 4–5 m tall; bark grey, smooth; young branches densely white pubescent. Leaves 8.5–23.6 cm long, white sericeous when young, white pubescent to tomentose when mature, paripinnate; stipules deciduous, triangular, 1–2 × 0.8–1 mm, densely tomentose on both surfaces and glandular–granulose on the adaxial surface; petiole 1.8–5.1 cm long; rachis 6.7–18.5 cm long; pinnae 3–4 (–5) pairs, (2.5–) 9–20 cm long; leaflets (3–6) 5–6 (–10), yugate, the proximal in the pinna is ovate and smaller, distal leaflets elliptic–ovate to elliptic–lanceolate and large, (1.6–) 2.5–5.6 (–6.6) × (1.1–) 1.5–2.5 (–3) cm, asymmetrical with the middle vein displaced towards the proximal margin, apex obtuse to rounded, margin ciliate, base cuneate, rounded or truncated, slightly oblique, glabrescent on the adaxial surface, pubescent to tomentose on the abaxial surface, conspicuously pellucid-punctated. Inflorescence, axillary raceme developing simultaneously with the leaves, or in branches without leaves; peduncle striated, densely white pubescent or hirtule. Male inflorescence, 10–23 cm long; bracts rhombic, caducous, 2.5–3.2 × 1.5–2 mm, apiculate, granular–granulose on the adaxial surface and densely tomentose on both surfaces. Flower pedicels 16.6–26.5 mm long, articulated at ¾–4/5 of their length, white puberulent to hirtule. Calyx green yellowish, densely white pubescent; tube obconic, cucullate, 6.2–7.3 × 3.4–4.3 mm. Sepals yellow, oblong to oblong–elliptic, 10.5–14 × (4–) 5–7.8 mm, apex acute or oblique, glandular fimbriate; lateral 9–13.4 × (3.5–) 4–6 mm, apex acute; abaxial cucullate, 16.7–18 × 10–12 mm, apex acute, glandular pectinate. Petals yellow, adaxial obovate to wide obovate, 7.5–8.5 × 7–9 mm, base curved forming an angle of 90º with the claw, apex rounded, margin wavy, base attenuated, conduplicate, claw 5.5–6 × 2.5–3.5 mm, conduplicate, forming a continuous channel to base, densely pilose on the abaxial surface; abaxial ovate 13–16 × 10.3–14 mm, apex rounded, margin entire or irregularly sinuous or split, base cuneate, claw 2.5–3.2 mm, pilose on both surfaces; abaxial obovate. All petals white pubescent and granular–glandular on the abaxial surface, glabrescent on the adaxial surface. Stamen filaments 8.3–10.5 mm long, slightly curved, wide and flattened at base, hairy up to ½ of its length, the rest glabrous; anthers oblong–ovate, 1–1.5 × 0.7–1 mm; style reduced, 0.3–1 mm long; stigma terminal, infundibuliform, ovary 1.5–2.7 mm long, hairy, stipe 0.7–2 mm long; ovules 3–4, rudimentary. Female inflorescence, 4–10 cm long; bracts rhombic, caducous, 2–2.5 × 1–2.5 mm, apiculate, granular–granulose on the adaxial surface and densely tomentose on both surfaces. Flower pedicels 4–7 mm, articulated at ¾ of their length, white–yellow puberulent to hirtule. Calyx green yellowish, densely white pubescent; tube obconic, cucullate, 7.2–9 × 3–4 (–6) mm. Sepals yellow, oblong to oblong–elliptic, 6 × 3 mm, apex acute or oblique, glandular fimbriate. Petals, yellow, lateral elliptic, 4–5.3 × 2–3.2 mm, claw 2–2.8 × 0.2–0.3 mm, apex acute; abaxial ovate, (5–) 4× 2 (–3) mm, apex rounded, claw 2 × 0.5–1 mm; adaxial obovate to wide obovate, 9–10 × 4–5 mm, base curved forming a 90º angle with the claw, apex rounded, margin wavy, base attenuated, conduplicate, 3 × 2–3 mm, conduplicate, forming a continuous channel to base, pilose on the abaxial margin surface; apex rounded, margin entire. All petals pubescent on the margin of claw, granular–glandular. Stamen filaments 6–8.5 mm long, slightly curved, wide and flattened at base, hairy up to ½ of its length, the rest glabrous; anthers oblong–ovate, 1–2 × 0.2–1 mm; style developed stipitate, 1 mm long; stigma, terminal, infundibuliform, margin ciliate; ovary 3–7 mm long, hairy; ovules 3–4. Legume, flat, oblong to elliptic, (6.3–) 7.3–12.6 × 2.8–4.4 cm, apex obtuse to rounded, base cuneate to rounded, septated between seeds, valves subchartaceous, ocher yellowish, margin hirtule; pedicels 14–28 mm, stipe thin, 4–7 (–10) mm long. Seeds elliptic to ovate, flat, 9.3–13 × 6.6–9 × 1.8–3 mm, olive–green to light brown, margin dark, testa transversely fissured.

Habitat:— It is located in a restricted area of Infiernillo region in the Rio Balsas Depression in the states of Guerrero and Michoacan, in the tropical deciduous forest, on rocky slopes or near temporary or permanent water currents; 200-350 m.

Distribution and phenology:— Known only from the states of Guerrero and Michoacan ( Fig. 3 ). It blooms from May to June and fruits from August. Fruits remain attached to the branches for a long time.

Etymology:— The epithet is dedicated to Gwilym P. Lewis who has spent more than 40 years working with Legumes. He has trained many students, posdocs, and colleagues in legume taxonomy, fieldwork, an herbarium curation.

Conservation assessment:— We recommend that Coulteria lewisiae be given a conservation assessment of Vulnerable [VU (B1b-iii)] in accordance with IUCN (2019) categories and criteria. The extent of occurrence (EOO) of C. lewisiae is estimated to be below the 20,000 km 2 upper limit for Vulnerable status under criterion B1. The species is currently known from fragmented vegetation in the states of Guerrero and Michoacan. The preferred habitat of the species is potentially threatened by settlement and agricultural activities, as well as by environmental problems associated with drug trafficking organizations.

Specimens examined:— México. Guerrero. Municipio de Zirándaro: 3 km al O del Guariche , 20 September 1989 [fr], J.L. Contreras 2535 ( FCME) ; 6 km al O del Guariche , 21 June 1989 [fl], 240 m, J. L. Contreras 2510 ( FCME) ; 1 km al N de Aratichanguio, camino Zirándaro-Aratichanguio , 23 July 2011, 196 m, J.C. Soto 19162 ( MEXU) ; en las afueras del poblado de Zirandaro . Camino a Aratichanguio , 13 June 1991, 200 m, J.L. Contreras 3020 [fl], 3021 [fl] ( MEXU) . Michoacán: Municipio de Arteaga: 38 km al noreste de Arteaga, por la carretera a Nueva Italia; 1 km al suroeste del entronque al Infiernillo , 5 June 1992, 350 m, J.L. Contreras 3143 [fl], 3144 [fl] ( MEXU) ; Municipio de Huetamo de Núñez: 9 km al O de Quetzería, 25 October 1980, 230 m, J.L. Contreras 700 ( FCME, MEXU) ; Municipio de Múngica: 1 km al norte del Capirio , cerca de una acequia de riego, 1 June 1990 [fr], J.L. Contreras 2767, 2768, 2769 ( MEXU) ; Puente Capirio, carretera Nueva Italia-Infiernillo , 15 June 1991, 200 m, J.L. Contreras 3048, 3049, 3050 ( MEXU) , 26 April 1992, 200 m, J.L. Contreras 3119 ( MEXU), 6 June 1992, 200m, J.L. Contreras 3162 (MEXU) .

Figures

FIGURE 1. Coulteria a-c pollen grains different views (J.L. Contreras 3048); d male flower style; e male flower stigma close up (J.L. Contreras 2510); f female flower stigma; g female flower abaxial sepal (JL. Contreras 3155).

FIGURE 2. Coulteria lewisiae showing many of the important features. a part of a bipinnate leaf; b ♂ flower lateral view; c ♀ flower lateral view; d standard petal; e lateral petal; f abaxial petal; g style; h stamens of a flower; i calyx; j fruits. Drawn from Contreras-Jiménez 2767, 3049 y 3050 (MEXU) by Albino Luna.

FIGURE 3. Coulteria lewisiae and close related species distribution map.