Phyllanthus catingicola D. Santos, Loiola & Marques-Torres, 2025

Santos, Diego, Sousa, Luana Mateus De, Torres, Alícia Marques, Silva, Marcos José Da & Loiola, Maria Iracema Bezerra, 2025, A New Species of Phyllanthus (Phyllanthaceae) from Northeastern Brazil, Phytotaxa 694 (1), pp. 93-100 : 94-97

Phyllanthus catingicola D. Santos, Loiola & Marques-Torres , sp. nov. ( Figures 1 , 2 )

Type:— BRAZIL. Ceará, Chaval, Pedra da Santa , 03º02’58”S, 41º15’17”W, 09 April 2024, fl., fr., F.D. Santos 871 (holotype: EAC!; isotypes: EAC!, HUEFS!, K!, PEUFR!, RB!, UFG!) .

Diagnosis: — Phyllanthus catingicola differs from P.hyssopifolioides by having a cylindrical main stem (vs. flattened in P. hyssopifolioides ), 5-merous staminate flowers with elliptical sepals (vs. 6-merous and orbicular), pistillate flowers with patelliform disk and capitate stigma (vs. 6-lobed and punctiform).

Description: —Erect herbs, 7–12 cm tall, monoecious; non-phyllantoid branching. Main stem cylindrical, glabrous, non-papillose, greenish; secondary branches flat, winged, glabrous, non-papillose, greenish. Cataphylls absent. Stipules ca. 1 mm long, lanceolate, apex acute, base truncated, margin entire, membranaceous, surface smooth, glabrous, persistent. Leaves alternate distichous, present on the main stem and secondary branches; petiole 0.5 mm long, cylindrical, glabrous, non-papillose; leaf blade 0.5–0.8 × 3.0–5.0 mm, oval or ovate-elliptical, base rounded, apex obtuse, sometimes rounded, margin entire, glabrous on both sides, membranaceous, concolor; brochidodromous venation with 4 or 5 pairs of secondary veins, printed on both sides. Cymules unisexual, axillary distributed along the main stem and secondary branches. Bracts ca. 1 mm long, lanceolate, apex acute, base truncate, scarious. Staminate cymules with 1 to 3 flowers; Pistillate cymules with 1 or 2 flowers. Staminate flowers: pedicel 0.3–0.6 mm long, cylindrical, non-papillose, glabrous; sepals 5, 0.5–0.6 mm long, elliptical or elliptical-obovate, apex obtuse or rounded, disk with 5-segmentes obtriangular, surface smooth, stamens 3, free, anthers horizontally dehiscent. Pistillate flowers: pedicel 0.3–0.4 mm long, cylindrical, non-papillose, glabrous; sepals 6, sometimes 5, 0.4–0.5 mm long, oblong, apex obtuse or rounded, membranaceous, margin entire; patelliform disk; ovary ca. 0.25 × 0.25, globose-depressed, non-papillose, styles 3, bifid, free, patent, stigma capitate. Capsule 0.7 × 0.7 mm, globose, greenish, glabrous, pedicellate, calyx and styles persistent. Seeds 0.20–0.22 mm long, trigonous, dark brown, verruculose.

Paratypes: — Brazil. Ceará: Chaval, Pedra da Carnaúba, 03º02’58”S, 41º15’17”W, 23 March 2024, fl., fr., M.I.B. Loiola 3046 (EAC).

Distribution and habitat: — Phyllanthus catingicola appears to be endemic to the northeastern region of Brazil, where it has so far been collected in the municipality of Chaval in the state of Ceará ( Fig. 3 ). It has large populations (> 50 individuals) in several rocky outcrops that are difficult to access and grows in moist, sandy and clayey soil on rocky outcrops in the Caatinga domain at around 17 meters of altitude. This species forms large populations associated with species of Cactaceae , Lythraceae and Poaceae .

Etymology: —The specific epithet “ catingicola ” refers to the Caatinga domain, in which the species is endemic. Furthermore, the new species is the only one from the section Loxopodium endemic to this domain, which is also rarely found in the Phyllanthus genus.

Phenology: —It was collected with flowers and fruits in March and April.

Preliminary conservation status: —Species classified as Data Deficient (DD), as it has an estimated area of occupancy of 10 km 2, and is only known from one location, not located in Conservation Units. In addition, the type of vegetation where it was found is common in the state of Ceará, indicating that with greater collection efforts its occurrence could be observed in other areas of the state.

Figures

FIGURE 1. Phyllanthus catingicola D. Santos, Loiola & Marques-Torres. A. Habit. B. Stipules, note the entire margin. C. Detail of the branches flattened and winged. D. Leaves. E. Staminate flower, note the disk with segments obtriangular. F. Pistillate flower in side view; G. pistillate flower in view from above, note the patelliform disk. H. Capsule. I. Seeds in side view, note the verruculose forehead (Drawings by Jonas Wesley, from the holotype).

FIGURE 2. Phyllanthus catingicola. A. Habitats of its occurrence. B. Habit. C. Habit, showing the non-phyllantoid branching pattern. D Main stem, showing leaves, flowers and fruits. E. Staminate flowers. F. Pistillate flower. G. Fertile branch, showing the fruits. H. Seed [Photos by Diego Santos].

FIGURE 3. Distribution of Phyllanthus catingicola in Brazil.A. Map of Brazil highlighting the state of Ceará in gray. B. Map of the state of Ceará, showing its border states. C. Map of the state of Ceará, showing the distribution points of the species. State abbreviations: AL= Alagoas; BA=Bahia; CE= Ceará; PB= Paraíba; PE= Pernambuco; PI= Piauí; RN= Rio Grande do Norte; SE=Sergipe.