Croton rottlerifolius Baillon (1864: 327)

Caruzo, Maria Beatriz Rossi & Cordeiro, Inês, 2013, Taxonomic revision of Croton section Cleodora (Euphorbiaceae), Phytotaxa 121 (1), pp. 1-41 : 27-29

16. Croton rottlerifolius Baillon (1864: 327) ( Fig. 10F–H ). Type:— BRAZIL. Minas Gerais: 1838, P. Claussen

788 (holotype P!, isotypes A, G).

Croton warmingii Müller Argoviensis (1873: 105) . Type:— BRAZIL. Minas Gerais: Uberaba, 1848, A.F. Regnell 1077 (lectotype UPS! designated by Caruzo & Cordeiro 2007: 582, isolectotypes A!, MO!, S!); Brasil, Minas Gerais, Lagoa Santa, 2 December 1864, Warming 1649 (syntypes C!, G-DC!); Brasil, Minas Gerais, s.dat., Riedel 1381, 1382 (syntype LE).

Shrubs to treelets 2.5–6 m tall; latex clear; stellate and appressed-stellate trichomes; branchlets cylindric, slightly striate, pubescent, pale stellate trichomes, scattered blackened trichomes. Leaves discolorous, with a pair of sessile saucer-shaped orange acropetiolar glands; lamina 5.5–18.5 × 3.5–17.5 cm, ovate to broadly ovate, apex acute, base cuneate to slightly truncate, margin entire to minutely serrate, with glands; upper surface glabrescent, simple trichomes, lower surface pubescent to sparsely pubescent, appressed-stellate trichomes, porrect; venation pinnate, brochidodromous; petiole 2–8 cm long; stipules ca. 2 mm long, entire, linear. Inflorescences ca. 18 cm long, terminal, lax, pendant, sometimes apparently branched; inflorescence axis cylindric, slightly striate, pubescent, stellate trichomes; proximal cymules bisexual, with 1 pistillate flower and 1–2 staminate flowers, distal cymules with 1–2 staminate flowers; bracts ca. 2 mm long, entire, linear to lanceolate; prophylls ca. 1 mm long, linear. Staminate flowers ca. 6 mm long, campanulate, pedicellate; pedicels ca. 3 mm long; calyx ca. 3 mm long, pubescent externally, pale stellate trichomes, glabrate internally; calyx lobes 5, united up to half of their length, then free for ca. 1.5 mm long, entire, equal, valvate, slightly imbricate, ovate, apex acute, margin villose; petals ca. 3 mm long, oblong-lanceolate, apex obtuse, simple trichomes externally, glabrate internally, margin villose; disk 5-segmented; stamens ca. 15, filaments filiform, villose, simple trichomes; anthers ellipsoid; receptacle villose with simple trichomes. Pistillate flowers ca. 7 mm long, campanulate, pedicellate; pedicels ca. 2 mm long, usually thicked and angled at the apex; calyx ca. 5 mm long, pubescent externally, grey-greenish, stellate trichomes, sometimes with a central strip covered by brown trichomes, glabrate internally; calyx lobes 5, united up to half of their length, then free for the terminal ca. 2.5 mm, entire, equal, imbricate, ovate to rhomboidal, sometimes with borders with a different texture, apex acute to obtuse, margin villose; petals absent; disc entire, flatly 5-lobed; ovary globose, pilose, stellate trichomes; styles 3, 4-fid, united at the base, then branching into 12 terminal arms, covered by stellate trichomes at the base, exserted from calyx. Fruits ca. 1.5 cm long, subglobose, smooth, pubescent, grey at the base, blackened at the apex, stellate trichomes; calyx lobes persistent, inconspicuously accrescent; seeds ca. 6 mm long, oblong; smooth to inconspicuously warty.

Distribution and habitat: —Endemic to Brazil, in states of Bahia, Minas Gerais, São Paulo and Mato Grosso do Sul, where it occurs in seasonally dry forests.

Phenology:— Flowering in January, March, September–December; fruiting in January–April and October–December.

Taxonomic notes: —Among the other species of Croton section Cleodora , C. rottlerifolius is most similar to C. fragrantulus , from seasonally dry forests of Bolivia and Peru, and C. hoffmannii , from moist and dry forests of Central America and northern South America, but differs from them in several features (table 2).

Selected specimens examined: — BRAZIL. São Paulo: Campinas, Fazenda Santa Elisa , semi-deciduous forest, 650m, 22°52’S, 47°04’W, fl., 10 October 1984, G.L. Webster & J.Y. Tamashiro 25380 (DAV, MBM, MICH, MO, UEC, UB) .

Figures

FIGURE 10. A–E. Croton pseudofragrans. A. Flowering branch (Coello 213). B. Bract 3-lobed (Coello 213). C. Pistillate flower (Coello 213). D. Gynoecium (Coello 213). E. Staminate flower (Coello 213). F–H. Croton rottlerifolius. F. Flowering branch, detail of the acropetiolar glands (Melo & Santos 984). G. Pistillate flower (Melo & Santos 984). H. Fruit (Caruzo et al. 111).