Croton campinarensis Secco, A.Rosário & P.E.Berry, 2012

Secco, Ricardo De S., Do Rosário, Alessandro S. & Berry, Paul E., 2012, Croton campinarensis (Euphorbiaceae), a new species from eastern Amazonian Brazil, Phytotaxa 49 (1), pp. 1-5 : 2

Croton campinarensis Secco, A.Rosário & P.E.Berry , sp. nov. ( Figs. 1A–J , 2 )

Type:— BRAZIL. Pará: Município do Acará, campina do Guajará , Alça Viária , 20 November 2009 (fl., fr.), R.S. Secco & A.S. Rosário PEA 928 (holotype MG!; isotypes K!, MICH!, NY!, RB!, SP!) .

Folia nervatura actinodroma , ad basin trinervia; inflorescentia 5 floribus pistillatis, 1 ad basin et 4 supra, illis staminatis quiescentibus secundus axin insertis; flores staminati 14–15 staminibus; flores pistillati sepalis (lobis) inaequalibus, stylis 12 ramis terminalibus.

Shrubs 1–2 m to small trees 3–4 m tall, densely branched and forming a dense tangle. Branches spreading, sometimes decumbent, densely pilose with stellate trichomes, becoming dark brownish-black when dried. Leaves alternate, chartaceous, 4–12 x 2–4.5 cm, deflexed, looking wilted, elliptic to elliptic-ovate, rough to the touch, venation actinodromous, trinerved at base, secondary veins noticeable on both sides, immersed on the adaxial side, prominent on the abaxial side; adaxial surface with stellate trichomes concentrated along the veins, the abaxial surface with a dense covering of stellate trichomes; base cordate, margin dentate-serrulate to incised-crenate, with stipitate abaxial glands in the sinuses between the teeth, apex acuminate; petiole 0.5–1.0 cm long, pilose, with a dense covering of stellate trichomes, and a pair of cupuliform, stipitate acropetiolar glands; stipules basal, lanceolate, pilose, caducous. Inflorescence with pistillate flowers generally 5, the basalmost one more distantly spaced than the distal ones, the staminate flowers more numerous and distal along the rest of the axis, the axis (2.0–)3.0– 6.5 cm long. Staminate flowers with pedicel 1.5 mm long, pubescent, ferrugineous, trichomes stellate, bracts 0.5–1.5 mm long, lanceolate, pubescent, early deciduous; sepals 5, free, 1.8–2 mm long, elliptic-ovate, externally pubescent, trichomes stellate, glabrous internally, margin with simple trichomes; petals 5, free, 2 mm long, ovate-spathulate to ovate-elliptic, glabrous externally, pilose internally, with a densely villous indument, especially at the base, margin villose; stamens 14–15, one of these in the center, 2.5–3 mm long, emerging from a tuft of simple trichomes, disk basal, lobed. Pistillate flowers with pedicel 1.5–2 mm long, pilose, ferrugineous, trichomes stellate, bracts 1.5–2.5 mm long, lanceolate, pubescent, quickly caducous; sepals basally connate, the calyx campanulate, lobes 5(–6), slightly unequal, becoming nearly equal in fruit, 3 of them elliptic-lanceolate, 4–4.5 mm long, the other 2(–3) elliptic-ovate, 5.5–6.0 mm long, with a dense covering of stellate trichomes externally, pubescent internally; petals 5, 1.0– 2 mm long, narrow, aciculate, reduced or obsolete in fruit; ovary subglobose and 3-lobed, 2.5–3 diam., densely pilose with stellate trichomes with a long central radius, styles 3, connate into a column at the base, then each style branched 4 times for a total of 12 tips, covered with stellate trichomes with a long central radius. Capsule 6–6.5 mm long, covered with stellate trichomes, calyx and styles persistent; seeds 4–5 mm long, ovoid, smooth, mottled, carunculate; caruncle winged, 1.0– 1.2 mm long.

Additional material examined (paratypes):— BRAZIL. Pará: approximately 18 km east of Tucuruí and Rio Tocantins, by BR 263, white-sand campina and campina forest (campinarana), 20 October 1981 (fl., fr.), D.C. Daly et al. 982 (IAN!, INPA!, NY!, MG!); Tucuruí, margem direita do Rio Tocantins, campina, 29 May 1981 (fl.), M.G. Silva & C. Rosário 5244 (INPA!, MG!, MO!); south of Belém near mouth of Rio Guamá , white sand savanna, 14 August 1986 (fl., fr.), T.B. Croat 62174 ( MG!, MO!); município do Acará, campina do Guajará, areial, PA068, 29 December 2008, E. Andrade & F. Nascimento 950 ( INPA!, MG!) .

Figures

FIGURE 1. Croton campinarensis. A. Flowering branch. B. Detail of a leaf base, with a pair of acropetiolar glands and a detail of a stalked marginal gland between the teeth. C. Inflorescence with proximal pistillate flowers and distal staminate ones. D. Staminate flower. E. Detail of a petal from a staminate flower, adaxial view. F. Pistillate flower with one sepal bent back. G. Gynoecium, with reduced petals at the base, and style with 12 terminal tips. H. Fruit. I. Seed with caruncle. J. Pistillate flower showing the unequal sepals: three elliptic-lanceolate and two elliptic-ovate. Drawings based on R. Secco & A. Rosário PEA 928.

FIGURE 2. Croton campinarensis. Photograph of the type specimen in situ; plant 1.5 m tall.