Croton jacobinensis Baillon (1864: 302)

Rossine, Yuri, Melo, André Laurênio De, Athiê-Souza, Sarah Maria & Sales, Margareth Ferreira De, 2023, Understanding the “ Marmeleiros ”: a taxonomic treatment of Croton sect. Lasiogyne (Euphorbiaceae) in Brazil, Phytotaxa 584 (4), pp. 219-250 : 235-236

6. Croton jacobinensis Baillon (1864: 302) .

— Croton auriculatus M̧ller Argoviensis (1865: 98) , nom. superfl.

Lectotype (designated by Rossine et al. 2021):— BRAZIL. Bahia: Jacobina, 1845, J.S. Blanchet 3661 ( P [ P00623531 !]; isolectotypes: G [ G00311368 !, G00434516 !], P [ P00623530 !], F [ F0093327F !], K [ K000253581 !], MA [ MA249987 !]) . Fig. 5 (k–o), 6 (b)

Croton sonderianus M ̧ller Argoviensis (1866: 557) . Holotype:— BRAZIL. Ceará: without locality, without date, Kalkmann 147 (G [ G00311377 !]).

Description: —Monoecious shrub, 1–3 m tall; latex translucent; monopodial branching, branches cylindrical, green to brown; trichomes stellate. Leaves alternate; stipules flabelliform to auriculate, less common lanceolate, 0.5–2.5 × 0.2–3.8 cm, usually persistent, with stellate trichomes; petiole cylindrical, 0.5–6 cm long, with stellate trichomes; leaf blade membranous, cordiform, 4–28 × 2–20 cm, slightly bifacial, adaxial face dark green with stellate trichomes, abaxial face opaque, light green to gray with stellate trichomes, base cordate, margins entire, apex acute, venation eucamptodromous, with 6–12 secondary veins. Thyrses 5–18 cm long, terminal, with stellate trichomes, peduncle 0.5– 1.5 cm long; cymules unisexual, lax, solitary flowers; bracts persistent, lanceolate, sometimes 3-lobed, two smaller lateral lobes inconspicuous, 3–4 × 2–2.5 mm, margins entire, apex acute, with stellate trichomes. Staminate flower with pedicels 2.5–5 mm long; sepals greenish, united for ⅓ of their length, lobes ovate, 3–3.5 × 2 mm, margins entire, apex acute, with stellate trichomes externally, glabrous internally; petals white, ovate to oblong, 3–4 × 1.5–2 mm, margins entire, apex acute to rounded, with simple trichomes externally, glabrous internally; stamens 14–17, filament ca. 2 mm long, anther elliptic, 0.4–0.8 × 0.2–0.4 mm; nectary disk 5-lobed, apex of lobes rounded, glabrous. Pistillate flower with pedicels 0.5–2 mm long; sepals green, united for ⅟ 4 of their length, lobes ovate to long ovate, equal in size, 4.5–8 × 2–5 mm, reduplicated vertically or both vertically and horizontally, margins entire, apex acute, with stellate trichomes externally and internally; petals absent; ovary spheroid to obloid, 2–3.5 × 2–3.8 mm, with stellate trichomes; styles patent, rarely ascending, free, multipartite, up to 24 stigmatic tips, with stellate trichomes; nectary disk 5-lobed, apex of lobes rounded, glabrous. Capsule light green, ovoid or spheroid to obloid, 4–6 × 4–7 mm, 3-lobed, rarely unlobed, surface non-muricate, with stellate trichomes; columella up to 5 mm long, striated, apex flattened. Seed brown to gray, spheroid, 3.5–4.5 × 3.5–4.5 mm, rugose, caruncle elliptic.

Vernacular names:— Marmeleiro branco, marmeleiro do brejo, marmeleiro de orelha.

Distribution and habitat, conservation status, and phenology: — Croton jacobinensis is endemic to the Caatinga domain ( Carneiro-Torres 2009), reaching transition areas between the Caatinga and the Atlantic Forest (Caruzo et al. 2022). It occurs in Minas Gerais and in northeastern Brazil (except for Alagoas and Maranh„o) ( Fig. 6 , b). C. jacobinensis is associated with the less xeric Caatinga environments, being frequently found in montane forests, higher altitude areas, and more rarely in anthropized sites, preferably in clayey soils. Although with a small AOO (424 km 2), C. jacobinensis is classified as of Least Concern (LC), based on its EOO (810,851.066 km 2) and its occurrence in several protected areas in the northeastern region of Brazil and in montane forests that have suffered little human impact. Flowering from November to May and fruiting from December to May.

Notes:— Croton jacobinensis can be identified by having lanceolate to flabelliform stipules, cordiform leaves, and the vertically and horizontally reduplicated sepals of its pistillate flower. It can be confused with C. compressus (the distinctions are presented in the comments concerning the latter species).

Representative specimens: — BRAZIL. Bahia: Lagedo do Tabocal, ca. 8 km em direç„o a Maracás , 25 February 2000, R. P . Oliveira 337 ( HUEFS) . Ceará: Crateús , RPPN Serra das Almas - sede, 5º14’71” S, 40º92’72” W, 14 January 2017, H. M . Meneses 79 ( EAC) . Minas Gerais: Caraça, without date, Gounelle s.n. ( P05509550 ) . Paraíba: Jacaraú, Timbó, Riacho do meio, 5 Mar. 2016, E. M . Almeida 1579 ( HUEFS) . Pernambuco: Carpina , 11 January 2007, L. P . Felix 11478 ( HUEFS) . Piauí: Piracuruca , estrada administrativa, 2 February 2002, A . Carvalho 91 ( UEC) . Rio Grande do Norte: Baia Formosa, próximo a entrada de Barra do Cunhaú , ca. 8 km da cidade, 6º21’07” S, 35º06’22” W, 2 November 2007, R. C . Oliveira et al. 2037 ( MOSS) .

Figures

FIGURE 5. a–e Croton compressus: a flowering branch with monopodial ramification b linear stipules, c staminate flower of 15 stamens, d pistillate flower with horizontally (and slightly vertically) reduplicated sepals, long ovoid ovary and free multipartite styles, e ovoid fruit showing vertically reduplicated sepals and multipartite styles, slightly united at the base. f–j C. floribundus: f flowering branch with monopodial ramification, g long-lanceolate stipules, h staminate flower of ca. 15 stamens, i pistillate flower with slightly vertically reduplicated sepals, spheroid ovary, and patent and multipartite styles, j spheroid fruit with muricate surface. k–o C. jacobinensis: k flowering branch with monopodial ramification, l flabelliform to auriculate stipules, m staminate flower of 15 stamens, n pistillate flower strongly reduplicated vertically and horizontally, with a multifid style, slightly united at the base, o spheroid to obloid fruit, 3-lobed.

FIGURE 6. Distribution of some species of section Lasiogyne. a Croton argyrophyllus, C. blanchetianus, and C. claussenianus; b C. compressus, C. floribundus, and C. jacobinensis.