Croton gnidiaceus Baillon (1864: 354)

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 : 176

3. Croton gnidiaceus Baillon (1864: 354) . Lectotype (designated here):— BRAZIL. Minas Gerais: Tiradentes, Serra de São José , 1816−1821 (fl, fr), A. Saint Hilaire cat. B2 2385 (P 00634790!, isolectotype F 0056130F). ( Fig. 5 , A–L)

Subshrubs, 0.4−0.6 m tall. Leaves imbricate and concentrated at the branch apices, subsessile with the petiole 1 mm long; leaf blade ovate-lanceolate, 0.6−1.3 × 0.3−0.7 cm, base acute, symmetric, margin entire, glandulose, apex rounded-obtuse, trichomes stellate, whitish on both surfaces, although appearing glabrous at first sight, palminerved at the base; stipules lanceolate, laciniate-glandulose, 0.6−0.9 mm long, caducous. Inflorescences 1−1.5 cm long, with a naked sterile zone between basal pistillate flowers and apical staminate ones, trichomes stellate; bracts linear-lanceolate, laciniate-glandulose, 1−2.5 mm long on the staminate flowers, 3 mm long on the pistillate ones, trichomes stellate on the adaxial surface. Staminate flowers 10−18 per inflorescence; pedicel 2 mm long; sepals 5, obovate, 2 × 0.8 mm, margin entire, trichomes stellate on both surfaces; petals 5, obovate, 1,5 × 1 mm, margin entire, ciliate; stamens 10−14, filaments 1.2 mm long, anthers ovoid, 1 × 0.5 mm, glabrous. Pistillate flowers 1−2 at the base of the inflorescence; subssessile; sepals 5, triangular-lanceolate, 7 × 2.8 mm, margin entire with sessile glands, trichomes stellate on the adaxial surface; petals 5, subflabelliform, whitish, 3 × 0.6 mm, margin entire, ciliate; ovary ovoid, 2.8 × 2.4 mm, trichomes stellate; styles multifid, 4−5 times branched at the base, 1.5−2 mm long, glabrous. Capsules globose, 4 mm diam., trichomes stellate brownish; seeds ellipsoid, 2.5 × 2 mm.

Distribution:—This species occurs in Serra de São José, 1430 m elevation, Tiradentes, and in Serra do Lenheiro, 1218 m elevation, São João del Rei, both located in Minas Gerais State. ( Fig. 6 ).

Additional specimens examined: — BRAZIL. Minas Gerais: São João del Rei, Serra do Lenheiro, 10 July 2004 (fl), D. Medeiros 240 & A.M. Werneck (R), D. Medeiros 241 & A.M. Werneck (R), D. Medeiros 242 & A.M. Werneck (R). Tiradentes, Serra de São José , Cachoeira do Mangue , June 2001 (fl), D. Medeiros 66 (R) ; Serra de São José, trilha entre Cachoeira do Mangue e Cachoeira do Bom Despacho , 11 July 2004 (fl), D. Medeiros 247 & A.M. Werneck (R), D. Medeiros 248 & A.M. Werneck (R) .

Taxonomic Notes: — Croton gnidiaceus differs from other species of subsect. Medea by its subflabelliform petals in the pistillate flowers. The leaf indumentum is lanose, but at first sight leaves seem to be glabrous. It works well as a distinctive character in the field. This species was recently rediscovered ( Medeiros et al. 2008).

Figures

FIGURE 5. Croton gnidiaceus. A. Branch; B. Stipule; C. Inflorescence; D. Staminate flower: E. Sepal (ventral side), F. Sepal (dorsal side); G. Petal (ventral side); H. Pistillate flower: I. Sepal (ventral side), J. Petal (dorsal side); K. Fruit; L. Seed (ventral side) (after D. Medeiros 66 (R); from Medeiros et al. 2008).

FIGURE 6. Distribution map of Croton gnidiaceus.