Coccoloba knappiana J.J.Ancona, 2025

Ancona, Juan José, Ortiz-Díaz, Juan Javier, Gutiérrez-Alonso, Eduardo & Ledesma, Patricia Hernández, 2025, A taxonomic revision of Coccoloba sect. Paniculatae (Polygonaceae, Eriogonoideae), Phytotaxa 704 (2), pp. 106-152 : 124-126

6. Coccoloba knappiana J.J.Ancona sp. nov. ( Figs. 9A–F ).

Type:— MEXICO. Jalisco: Casimiro, Castillo, Reserva de la Biósfera Sierra de Manantlán, 2 km al sureste de Casimiro Castillo, 19°35ʹ16ʺN, 104°24ʹ48ʺW, 800 m. 23 September 1993, Santana & Benz 6634 (holotype MEXU!).

Diagnosis:— Coccoloba knappiana is morphologically similar to C. matudae , distinguished by the shape of the blade narrow elliptic to elliptic (vs elliptic or broadly elliptic); inflorescence spiciform, pedicel in fruit 0.5–0.8 mm long (vs inflorescence racemiform, pedicel 3–4 mm); acrosarcum 6–7 × 5–6 mm (vs 9.5–10.5 × 6.5–7.7); achene globose, 6× 6 mm (vs ovoid, 7.3–7.7 × 6.4–7 mm).

Description:—Trees hermaphrodites, functionally unisexual, 8–15 m tall; branches striate, glabrous, brown to greyish, lenticelated or sparsely punctiform; ochrea 4–7 mm long, cylindrical, glabrous, membranaceous, brown, apex lacerated. Leaves simple, alternate; petioles 10–18 mm long x 0.5–1.78 mm diameter, striate, glabrous, brown, arising at the base of the ochrea; leaf blades 10–18 cm long, 3–5.5 cm wide, narrowly elliptic to elliptic, chartaceous to coriaceous, glabrous on both surface, margin entire to slightly undulate, apex acute, base rounded to truncate sometimes slightly decurrent on petiole; venation brochidodromous, reticulate, prominent, primary veins 8–12 pairs, prominent. Inflorescence spiciform, arranged in a small sympodial panicle, branches 2–3, main axis reduced, 1.5–2 cm long, striate, glabrous; spiciform portion 11–27 cm long, rachis 0.5–0.8 mm diameter, raquis estriated, glabrous to puberulent; bracteole 0.4–0.8 mm long, cymbiform, glabrous to puberulent, pulverulent; ochreola 0.4–0.8 mm long, cylindrical, membranous, pulverulent, apex rounded, lacerate; pedicels 0.4 in flowers, 0.5–0.8 mm long in fruit, thicker. Flowers in two whorls, outer tepals 3, inner tepals 2, alternate; flowers functionally male 2 × fascicle, only flower buds were found; flowers functionally female solitary, hypanthium 08– 1 mm long, glabrous, campanulate, not abruptly narrowed at the pedicel; outer tepals glabrous, coriaceous, inner tepals glabrous, papyraceous; tepals 0.8–1 mm long; stamens 8, 2.5 mm long, filaments filiform 2 mm long, anthers 0.5 mm long; ovary 1 mm long, ovoid, glabrous, style 3, 1 mm long. Fruit acrosarcum, 6–7.5 × 5–6 mm, ovoid to subglobose, obtuse apex, truncated base, contracted at junction with pedicel, brown, glabrous; hypanthium accrescent, succulent, almost completely enclosing achene, tepals accrescent, appressed at the apex slightly tuberculate of the achene; achene 6 mm long, 6 mm diameter, globose, base rounded, apex tuberculate, depressed–galeate, slightly prominent.

Etymology:—The specific name is dedicated to Dr. Sandra Diane Knapp, research botanist at the Natural History Museum London and editor of Flora Mesoamericana who has developed the treatment of various genera of Polygonaceae for this flora.

Phenology:—Flowers from July to August; and fruits from August to September.

Distribution and ecology:—This species in endemic to Jalisco, Mexico ( Fig. 9G ). The specimens collected so far are restricted to the dry forests of the Casimiro Castillo municipality, in the “Reserva de la Biósfera Sierra de Manantlán”, at elevation from 600 to 1000 m.

Provisional conservation status:—Given the extremely narrow geographic distribution (AOO= 12 km 2) and the small number of occurrences (four). In addition, the four occurrences are located within the Sierra de Manantlán protected natural area. Therefore, under the IUCN Red List criteria ( IUCN Standards and Petitions Committee 2024), we propose a preliminary IUCN Red List Assessment of Vulnerable [VU D2]. Any future documentation of negative population trends, increased threats, or lapses in appropriate fire management that would degrade habit quality would likely change the assessment toward Endangered under the B criteria.

Specimens examined: — MEXICO, Jalisco: Casimiro Castillo , 2 km al SE de Casimiro Castillo, 19°35ʹ16ʺN, 104°24ʹ48ʺW, elev. 750 m, 3 August 1993, Santana & Benz 6367 ( MEXU) ; Casimiro Castillo, Arroyo La Calera , 7 km al NNE de C. Castillo, 19°40ʹ16ʺN, 104°25ʹ04ʺW, elev. 800–1000 m, 14 July 1988, Cuevas & Núñez 3067 ( MEXU) ; Casimiro Castillo , La Calera, 16 km al SE de Autlán, 19°38ʹ37ʺN, 104°22ʹ07ʺW, elev. 600–800 m, 17 August 1988, Guzmán & Santana 301 ( MEXU) .

Figures

FIGURE 9. A. Specimen of Coccoloba knappiana (F.J. Santana & B.F. Benz 6634, MEXU); B. Portion of inflorescence and fruit; C. Acrosarcum lateral view; D. Acrosarcum polar view; E. Achene lateral view; F. Achene polar view; G. Geographical distribution.