Xylopia glomerulosa Pontes-Pires, 2021

Pontes-Pires, Aline Fernandes, Murray, Nancy A., Johnson, David M. & Barbosa, Maria Regina De V., 2021, A new species of Xylopia (Annonaceae) from the Peruvian Amazon, Phytotaxa 514 (2), pp. 181-186 : 181-183

Xylopia glomerulosa Pontes-Pires , sp. nov. ( Fig. 1 )

Type:— PERU. Loreto Department: Maynas Province , Distrito Iquitos, C.I. Puerto Almendras ( UNAP) Arboretum , 122 m, 3°48ʹS, 73°25ʹW, 24 Sep 1991, Grández & Jaramillo 2873 (holotype: MO1837714!; isotypes: OWU!, U0131055 digital image!) .

Xylopia glomerulosa resembles X. sericea but can be distinguished by its wider leaf blades with extremely dense sericeous indument abaxially and longer leaf acumen, glomerular and generally congested inflorescences, sepal-like middle bract, wider woody monocarps and larger seeds.

Trees 13–28 m tall, dbh ca. 30 cm. Twigs, petioles, abaxial surfaces of leaves and fruits with golden, yellowish, pale rusty, or pale brown hairs. Inflorescences and flowers with golden to golden-hyaline hairs. Twigs densely tomentose, becoming glabrate when older. Petioles canaliculate, 4.0– 7.5 mm long, dark brown to brown, densely tomentose; leaf blades narrowly elliptic, lanceolate, oblong-lanceolate or elliptic, (12.3–)14.5–18.4 × 3.8–4.8(–5.3) cm, glabrous except for some hairs at the base of the midrib adaxially, extremely densely sericeous abaxially, apex acuminate, acumen (15.0–)18.0–23.0 mm long, base cuneate to broadly cuneate, truncate, or sometimes obtuse, or obliquely angular and frequently revolute at the angles, midrib impressed adaxially, raised and keeled abaxially, secondary veins 9–13 per side, raised on both surfaces, less visible abaxially because of the dense indument. Inflorescences axillary, sometimes borne from the axils of fallen leaves and often at multiple nodes on a same twig, (5–)9–22-flowered, glomerular, generally congested; peduncles 2.0–3.0 mm long, sericeous; pedicels 1.5–3.0 mm long, sericeous; bracts 2, (2.2–)3.5–4.0 × 3.0– 6.5 mm, one at the base of the pedicel, one at the midpoint, clasping, glabrous adaxially, densely sericeous to tomentose abaxially; basal bract ovate, caducous, apex acute; middle bract ovate, usually bilobed by splitting down the middle, sepal-like, persistent, apex acute; buds narrowly oblong, slightly panduriform. Sepals ovate, connate at the base, ca. (⅓–)⅕ connate, 3.7–4.5 × 3.5 mm, smooth, glabrous adaxially, densely sericeous abaxially, apex acute; petals white, whitish, or yellowish in vivo; outer petals narrowly oblong, slightly panduriform, or nearly lanceolate, apex acute to slightly rounded, (13.0–)15.0–17.0 mm long, 2.0– 2.5 mm wide at base, 1.3–2.2 mm wide at constriction, 2.2–2.5 mm wide at midpoint, tomentellous, glabrous at base adaxially, densely sericeous abaxially; inner petals nearly lanceolate overall, apical portion narrowly lanceolate, enlarged and concave at the base, 11.0–13.0 × 1.5–2.5 mm at base, 1.0 mm wide at constriction, 1.0– 1.5 mm wide at midpoint, tomentellous, glabrous below midpoint, adaxially, tomentellous with base short sericeous abaxially, apex acute; stamens 155–190, fertile stamens 100–120, nearly club- or dumbbell-shaped, 0.7–1.0 × 0.1–0.2 mm, glabrous, apex of the connective capitate, discoid or sometimes triangular, 0.1–0.2 mm long, papillate, anthers (4–)5–8-locellate, filament 0.15–0.30 mm long; outer staminodes ca. 35, nearly club- or dumbbell-shaped, 0.7–0.8(–1.0) mm long, glabrous, apex of connective irregularly shaped, triangular, or capitate, 0.2–0.3 mm long, papillate, anthers shorter than in the fertile stamens, (4–)5–8–locellate, locelli slightly distinct or absent, filament 0.15–0.20 mm long; inner staminodes 20–35, obtriangular to obovate, (0.4–)0.5–0.7 × 0.3–0.4(–0.5) mm, glabrous, apex of connective slightly differentiated, papillate, anther sacs and filaments not differentiated; staminal cone urceolate to globose, 1.2–1.5 mm in diameter, 1.0– 1.2 mm high; carpels 4–6, 3.9–5.0 mm long, ovary lanceoloid, 0.9–1.0 mm long, densely sericeous; stigmas ellipsoid, ovoid, or oblanceoloid at the base, sharply narrowed above base, filiform from constriction to apex, 3.0–4.0 mm long, finely verruculose, glabrous; ovules 2–4. Fruits of 4–5 monocarps borne on a pedicel 3.0–6.0 mm long, tomentellous to tomentose; torus nearly globose, 3.7–5.5 mm in diameter, 2.5–3.0 mm high. Monocarps red to reddish in vivo, reniform, or oblong, slightly curved, obliquely clavate, sunken in some parts when dried, not constricted between seeds, 14.0–22.0 (excluding stipe) × 12.0–16.0 mm, woody, slightly verruculose, appressed pubescent to tomentellous, becoming sparsely pubescent when older, apex rounded; stipes slightly rugose longitudinally, (1.5–)3.0– 4.5 mm long, 2.0– 2.5 mm thick, densely pubescent to tomentellous; pericarp 0.6–0.8 mm thick. Seeds 3–4, ellipsoid to obovoid, in a single row perpendicular to long axis of monocarp, 7.9–9.5 × 5.8–6.1 × 4.2–4.9 mm, smooth, dark brown to black, aril bilobed, pale brown to amber-coloured when dry, translucent, lobes ovoid, semicircular to nearly quadrate, 1.5–4.0 × 2.0– 4.5 mm, surface smooth.

Vernacular names:— Carahuasca (Rimachi Y. 9067), yahuarachi (Vásquez & Jaramillo 8598) and yahuarachi caspi (Ruíz & Mendoza 520; Ruíz 513).

Distribution and habitat:— Known from Loreto Department, municipalities of Iquitos (Maynas Province) and Nauta (Loreto Province) in northeastern Peru ( Fig. 2 ). It appears to be endemic to the Peruvian Amazon, where it occurs mostly in white sand habitats, but it also occurs in upland and seasonally flooded forests, on sandy, sandy clay or clayey soils (based on the herbarium labels). The label of Vásquez & Jaramillo 15799 indicates that the palms Lepidocaryum tessmannii Burret (1929: 771) , a synonym of L. tenue Martius (1824: 51) , and a species of Scheelea Karsten (1856: 264) were dominant species in the collecting site.

Preliminary conservation status:— Endangered (B1 b, c (i, ii); B2 b, c (i, ii)). The extent of occurrence of Xylopia glomerulosa is about 3,130 km 2 and the area of occupancy, based on cells of 4 km 2, is 40 km 2. According to Zárate Gómez et al. (2015), the varillales (the name of the white sand forests in the Peruvian Amazon) constitute singular plant communities with a high number of endemic species, some of which are threatened; the varillales are also a source of logs and sand for construction. The anthropic pressure on the small areas of white sand habitat in this region thus seems to be high. Most of the Amazonian white sand forests in Peru occur over approximately 570 km 2 and are located particularly in the Jenaro Herrera District and in the Allpahuayo Mishana Reserve Zone of Loreto Department ( Peñuela Mora 2014). Of the 15 collections of X. glomerulosa , five were collected in Allpahuayo, near or inside the area of the current Allpahuayo Mishana National Reserve. Clearly, this natural reserve is critical to preserving not only X. glomerulosa , but the entire Peruvian white sand forest flora. All collections of X. glomerulosa were made between the years of 1972 and 1997, except for one collection from 2008.

Etymology: — Specific epithet referring to the congested inflorescence, resembling a glomerule.

Phenology:— Flowering February–March and September–October, fruiting November–March. Flowers with Gardenia Ellis (1761: 935) fragrance (McDaniel & Rimachi Y. 20177).

Notes:— Xylopia glomerulosa resembles X. sericea mainly when the specimens of the latter have leaf blades longer and wider than the usual, but X. glomerulosa can be easily distinguished by its leaf blade width and indument, length of the leaf acumen, inflorescence type, middle bract shape, monocarp width and seed size ( Table 1).

Additional specimens examined:— PERU. Loreto Department. Loreto Province: Nauta, carretera a Iquitos , 150 m, 4°29ʹS, 73°35ʹW, 12 Dec 1986, Vásquez & Jaramillo 8598 (F, MO, NY, U) ; Caserio Miraflores en la boca del río Tigre , 106 m, 4°27ʹ37ʺS, 74°04ʹ51ʺW, 8 Nov 2008, Vásquez et al. 34673 (L, MO, OWU) . Maynas Province: Distrito Iquitos, Allpahuayo ( Centro de Esperimentos del IIAP), a 20 km de la ciudad, Carretera Iquitos-Nauta , 150 m, 4°10ʹS, 73°30ʹW, 22 Nov 1984, Ruíz & Mendoza 520 (F, MO, NY, U) ; loc. cit., km 20, 15 Feb 1985, Ruíz 513 ( NY) ; loc. cit., 12 Sep 1990, Vásquez et al. 14382 (MO, OWU, U) ; loc. cit., 11 Oct 1990, Vásquez & Jaramillo 14514 (MO, OWU, U) ; loc. cit., 150– 180 m, 4°10ʹS, 73°30ʹW, Dec 1990, Vásquez & Jaramillo 15799 (MO, U) ; Carretera Iquitos-Nauta, entre Quistococha y Moralillo , ca. 130 m, 5 Sep 1979, Diaz & Jaramillo 1336 (MO, U) ; Carretera Iquitos-Nauta , km 5, trocha del caserio de “San Fernando”, ca. 130–150 m, 30 Jan 1989, Rimachi Y. 9067 (MO [2 sheets], NY [2 sheets], US) ; Cuyana, Río Nanay , 122 m, 3°44ʹ49ʺS, 73°14ʹ31ʺW, 14 Mar 1997, Vásquez & Rojas 22716 (MO [2 sheets], NY [2 sheets]) ; Pto Almendras, Río Nanay , 122 m, 3°45ʹS, 73°25ʹW, 25 Oct 1984, Vásquez & Jaramillo 5851 (MO, NY, U) ; Río Mamón [Río Momón], 4 Sep 1972, Croat 19970 (AAU, F, L, MO, NSW, NY, RSA, WAG) ; Río Nanay, Carretera de Picuruyacu, below Bellavista , ca. 150-180 m, 22 Sep 1975, McDaniel & Rimachi Y. 20177 ( MO) ; loc. cit., Carretera de Picuyacu , ca. 160 m, 10 Sep 1979, Rimachi Y. 4592 (MO, RSA) .

Figures

FIGURE 1. Xylopia glomerulosa. A. Branch with leaves and inflorescences. B. Detail of the indument on the abaxial face of a leaf. C. Detail of the glomerular inflorescence. D. Flower bud, with bilobed sepal-like middle bract persistent. E. Flower at the beginning of anthesis. F. Fertile stamen, abaxial view. G–I. Outer staminodes, abaxial view. J–K. Inner staminodes, abaxial view. L. Carpel. M. Fruit with four monocarps. N–O. Seeds with bilobed aril, longitudinal view.A–B: Grández & Jaramillo 2873 (MO), holotype; C: Vásquez et al. 14382 (MO); D, G–I, L: Grández & Jaramillo 2873 (OWU), isotype; E: Vásquez & Jaramillo 14514 (MO); F, J–K: Vásquez et al. 14382 (OWU); M: Vásquez & Jaramillo 8598 (MO); N–O: Vásquez & Rojas 22716 (MO, sheet 2). Drawing by Regina Carvalho.

FIGURE 2. Distribution of Xylopia glomerulosa.