Croton sp.

Sodré, Rodolfo C., Berry, Paul E. & Da Silva, Marcos J., 2017, The tribe Crotoneae (Euphorbiaceae, Crotonoideae) in the Chapada dos Veadeiros, Goiás, Brazil, Phytotaxa 321 (1), pp. 1-59 : 55-56

2.33. Croton sp. ( Fig. 23 , F–I)

Tree 5–12 m tall, erect, stems grayish with shortly stipitate dendritic-stellate trichomes; latex clear. Stipules 1–9 × 0.3– 1.4 mm, linear to oblanceolate, without glands, persistent; petioles 1.3–2.5 cm long, with 2(4) ellipsoid acropetiolar (lateral) glands. Leaves alternate, blades 7.5–14.3 × 2.6–4.5 cm, narrowly elliptic or oblong, base obtuse or discretely cordate, apex acute, margin entire, without glands; upper surface glabrous and lower surface with shortly stipitate dendritic-stellate or stellate-porrect trichomes, chartaceous, venation brochidodromous, with 20–34 pairs of secondary veins. Thyrses 6–20.5 cm long, terminal, staminate cymules with 1–3 staminate flowers; inflorescence axis, dorsal surface of bracts of both flowers, both surfaces of pistillate petals and sepals of both flowers, ovary and styles with shortly stipitate dendritic-stellate or stellate-porrect trichomes; bracts of both flowers 2.3–3.2 × 0.5–1 mm, oblanceolate to oblong, without glands. Staminate flowers 8–13.5 mm long, pedicels 2.5–6 mm long; sepals 5, 3.5–4 × 2–2.7 mm, ovate, apex acute; petals 5, 2–4 × 0.2–0.6 mm, linear to narrowly lanceolate, apex acute, villous on both surfaces; stamens 11–13(–16), filaments villous. Pistillate flowers 9–13 mm long, pedicels 2.7–5.5 mm long; sepals 5, 5.5–7 × 2.4–4 mm, subequal, reduplicate, ovate or oval-lanceolate, apex acute, margins entire, without glands; petals 5, 0.6–3 × 0.1–0.4 mm, linear or narrowly lanceolate, disk entire; ovary 1.8–2 mm long, globose, styles multifid, pubescent. Capsules 6–6.3 mm long, globose, greenish; seeds not seen.

Specimens examined:— BRAZIL. Goiás: Alto Paraíso de Goiás, estrada de chão entre São Jorge e Colinas , fazenda Novo Horizonte , margem do rio Tocantins, ca. 50 metros da barra do rio São Miguel , 14°16’38”S, 47°55’0”W, 14 November 1996, R. C. Mendonça, J. M. Felfili & M. Cláudio Silva Jr. 2990 ( IBGE) ; Cavalcante, estrada de terra saindo da balsa do “Porto dos Paulistas” (no rio Tocantins) para o Buracão, a cerca de 27.7 Km do rio, 13°21’52”S, 48°1’37”W, 440 m, 09 November 2000, B. M. T. Walter et al. 4652 ( CEN, UFG) ; rio Preto, em mata ripária próxima a ponte que leva à agropecuária Gavião , 14°7’26,3”S, 47°54’49”W, 461 m, 01 November 2013, R. C. Sodré, M. J. Silva & L. L. C. Antunes 938 ( UFG), 939 ( UFG) ; ibd., 13 December 2013, R. C. Sodré et al. 1061 ( UFG) .

This species is known from Goiás and Tocantins states; it is new to science and will be described in a separate publication with additional authors. It grows in gallery forest of the rio Brack in the municipality of Cavalcante ( Fig. 16D ). It can be differentiated from others species in the Chapada dos Veadeiros by the arboreal habit, cinereous branches with shortly stipitate dendritic-stellate trichomes, stipules without glands, leaf blade 7.5–14.3 × 2.6–4.5 cm, narrowly elliptic or oblong with upper surface glabrous and lower surface with shortly stipitate dendritic-stellate or stellate-porrect trichomes, besides chartaceous consistency and venation brochidodromous with 20–34 pairs of secondary veins.

Figures

FIGURE 16. Map of geografic distribution of the Crotoneae species in the Chapada dos Veadeiros, Goiás, Brazil.A. Croton longifolius, C. megalocalyx andC. odontadenius. B.C. planaltoanus, C.sclerocalyx and C. siderophyllus. C. C.spica, C.subacutus and C.subferrugineus. D. C. subvillosus, C. urucurana and Croton sp.

FIGURE 23. A−E. Croton urucurana. A. Flowering branch. B. Detail of the lower side of a leaf base showing the basilaminar glands. C. Staminate flower. D. Pistillate flower. E. Capsule. (A−E: R. C. Sodré et al. 580). F−I. Croton sp. F. Flowering branch. G. Detail of a leaf base showing the acropetiolar gland. H. Staminate flower. I. Pistillate flower. (F−I: R. C. Sodré, M. J. Silva & L.L.C. Antunes 938).