Croton siderophyllus Baillon (1864: 305)

Medeiros, Débora, Valle, Luci De Senna, Esser, Hans-Joachim & Alves, Ruy José Válka, 2016, Floristic and taxonomic treatment of Croton subsect. Medea (Euphorbiaceae) from Brazilian campos rupestres, Phytotaxa 263 (3), pp. 167-201 : 189-190

8. Croton siderophyllus Baillon (1864: 305) .— Croton claussenianus var. tomentellus Müller Argoviensis (1865: 129) . Lectotype (designated here):— BRAZIL. Minas Gerais: Serra da Caraça, 1839 (fl), P. Claussen 110 (P 00634674!, isolectotypes A 00277220!, G-DC 00312522!, P 00634673!, SP 000666!). ( Fig. 15 , A–L)

Croton claussenianus var. hirsutus Müller Argoviensis (1865: 129) .— Croton siderophyllus var. hirsutus (Müll.Arg.) Müller Argoviensis (1866: 650) . Type:— BRAZIL. Minas Gerais: Serra Moeda, no date, F. Sellow s.n. (holo B).

Shrubs, 0.4−1.4 m, branches irregularly dichotomous, dense, reddish. Leaves concentrated at the branch apices, not imbricate, petiolate with the 7−10 mm long; leaf blade ovate-lanceolate, 3.5−4 × 1.3−1.5 cm, base acute, asymmetric, margin irregularly serrate except the base, with a sessile gland on each tooth, apex acute, trichomes stellate on both surfaces, nearly absent (subglabrous) on the adaxial one, penninerved, venation conspicuous up to ¼ or ½ of the length; stipules linear-lanceolate, laciniate-glandulose, 2−2.5 cm long, trichomes stellate on the adaxial surface, persistent, inconspicuous. Inflorescences 1−3 cm long; bracts lanceolate, laciniate-glandulose, trichomes stellate on the adaxial surface, absent on the abaxial one, 3 mm long in the staminate flowers, 3−3.5 mm long in the pistillate flowers. Staminate flowers 18−20 per inflorescence, pedicel 1.3 mm long; sepals 5, ovate-lanceolate, 2 × 1.2 mm, margin entire, trichomes stellate on the adaxial surface, absent on the abaxial one; petals 5, ovate-lanceolate, 1.8 × 1 mm, margin entire, ciliate; stamens 11, filaments 2.1 mm long, anthers elliptic, 0.7 × 0.5 mm, glabrous. Pistillate flowers 2−3 at the base of the inflorescence, sessile; sepals 5, obovate-lanceolate, 3.5−4 × 1−1.2 mm, margin stipitate-glandulose, stipitate parts 0.5 mm, concentrated at the base of the sepal, trichomes stellate on the adaxial surface; petals 5, glanduliform, inconspicuous, 0.2 mm long, sessile; ovary globose, 1.3 × 1.3 mm; styles multifid, 4−6 times branched at the base, 1.5−2 mm long, apex rolled, trichomes stellate at the basal ⅔ of the length, persistent, glabrous. Capsules globose, 4 × 4 mm diam., trichomes stellate whitish in fresh material; seeds ellipsoid, 3 × 1.5 mm, maculate.

Distribution: — Bahia State, Espinhaço Range, Serra do Gentio, 1130 m elevation, and Minas Gerais, Planalto Diamantino, 1082−1548 m elevation ( Fig. 16 )

Additional specimens examined: — BRAZIL. Bahia: Abaíra, 13 o 30’S, 41 o 59’W, 30 May 1994, W. Ganev 3270 (HUEFS). Piatã, São Bartolomeu, Serra do Gentio, 13º02’04”S, 41º54’14”W, 9.3 km ao norte de Piatã na Rodovia BA-148 e 7.1 km na estrada vicinal para Inúbia e 6.8 km a nordeste desta, 28 December 2004 (fl), R.C. Forzza & R. Mello-Silva 2795 (RB). Minas Gerais: Belo Horizonte, Reserva da Mutuca , COPASA, 16 November 1989 (fl), N.C. Attala et al. 117 (BHCB) ; Serra do Curral , 30 January 1970 (fl), E. Pereira 2459 & Pabst 3295 (RB) ; Serra do Taquaril , no date (fl), M. Barreto 2700 (BHCB 63300) ; Betim, entre os municípios Betim e Brumadinho , 05 March 1940 (fl), M. Barreto 10681 (BHCB) ; Diamantina, Biribiri, 1904 (fl), C.A.W. Schwacke s.n. (BHCB 586); Biribiri , perto do Rio das Pedras, 18º09’S, 43º36’W, 14 February 1991 (fl), M.T.V.A. Campos et al. 5056 (SPF) ; Biribiri, estrada para Mendanha BR-367, 18º10’29”S, 43º30’52” W, 22 January 2004 (fl, fr), R. Mello-Silva et al. 2470 (SPF 163753) ; Biribiri , 20 January 2005 (fl, fr), D. Medeiros 332 & A.M. Werneck (R) ; D. Medeiros 333 & A.M. Werneck (R); D. Medeiros 334 & A.M. Werneck (R); D. Medeiros 341 & A.M. Werneck (R); D. Medeiros 342 & A.M. Werneck (R); D. Medeiros 343 & A.M. Werneck (R); D. Medeiros 344 & A.M. Werneck (R); Biribiri , 22 January 2005 (fl, fr), D. Medeiros 389 & A.M. Werneck (R) ; D. Medeiros 390 & A.M. Werneck (R); D. Medeiros 391 & A.M. Werneck (R); D. Medeiros 392 & A.M. Werneck (R); D. Medeiros 393 & A.M. Werneck (R); D. Medeiros 394 & A.M. Werneck (R); D. Medeiros 395 & A.M. Werneck (R); D. Medeiros 396 & A.M. Werneck (R); D. Medeiros 397 & A.M. Werneck (R); D. Medeiros 398 & A.M. Werneck (R); D. Medeiros 399 & A.M. Werneck (R); D. Medeiros 400 & A.M. Werneck (R); D. Medeiros 401 & A.M. Werneck (R); estrada de Diamantina para Couto de Magalhães de Minas, cerca de 1.5 km a leste da ponte sobre o Córrego Carrapato , 18 o 07’S, 43 o 32’W, no date (fl), no collector (SPF 143276) ; Rio Vermelho, Pedra Menina, Fazenda Vargem do Anjo , Morro do Espigão do Meio , 13 October 1984 (fl), R. Mello Silva et al. s.n. (SPF 35324) .

Taxonomic notes: —In fresh material and recently dried material, the fruits are white due to the indumentum. This character easily distinguishes this species from the remainder of the subsection.

Figures

FIGURE 15. Croton siderophyllus. A. Branch; B. Stipule; C. Inflorescence; D. Staminate flower: E. Stamen, F. Petal (ventral side), G. Sepal (ventral side); H. Pistillate flower: I. Sepal (ventral side), J. Gynoecium; K. Fruit; L. Seed (dorsal and ventral side) (after D. Medeiros 396 & A.M. Werneck (R)).

FIGURE 16. Distribution map of Croton siderophyllus.