Croton fragrans Kunth, 1817

Caruzo, Maria Beatriz Rossi & Cordeiro, Inês, 2013, Taxonomic revision of Croton section Cleodora (Euphorbiaceae), Phytotaxa 121 (1), pp. 1-41 : 22

11. Croton fragrans Kunth (in Bonpland, Humboldt & Kunth 1817: 81) ( Fig. 9F–K ). Type:— COLOMBIA. Tolima: Crescit locis calidis, frondosis prope Honda Novogravatensium , in ripa Magdalenae et in via ad urbem Guaduas in radicibus montis El Sargento , s.dat., A.J.A. Bonpland & F. W. H.A. von Humboldt s.n. (holotype P [00669877]!) .

Shrubs to treelets, 1.5–3.5 m tall; latex clear; multiradiate, rosulate and stellate trichomes; branchlets angled, striate, tomentose, multiradiate and rosulate trichomes. Leaves discolorous, with 1(2) pair of shortly stalked saucer-shaped acropetiolar glands; lamina 8–21 × 3–12 cm, ovate, apex acuminate to long acuminate, base rounded to obtuse, margin serrate to minutely serrate, with glands; upper surface pubescent to sparsely pubescent, simple and stellate trichomes, lower surface densely pubescent to pubescent, multiradiate and stellate trichomes; venation pinnate, craspedodromous; petiole 0.8–1.7 cm long; stipules 6–10 mm long, deeply lacerate, broadly ovate. Inflorescences 8–18 cm long, terminal, lax; inflorescence axis cylindric, striate, tomentose, multiradiate and stellate trichomes; proximal cymules bisexual, with 1 pistillate flower and 1 staminate flower, distal cymules with ca. 3 staminate flowers; bracts 4–7 mm long, lacerate, ovate, apex acuminate, prophylls 2–4 mm long, linear-lanceolate. Staminate flowers 0.8–1.1 cm long, subcampanulate, long pedicellate; pedicels 4–6 mm long; calyx 3–5 mm long, densely pubescent externally, multiradiate and rosulate trichomes, glabrate internally; calyx lobes 5, united up to half of their length, then free for the terminal ca. 2 mm, entire, equal, valvate, ovate, apex acute, margin villose; petals 4–5 mm long, spathulate, apex wavy and indented, margin villose; disk 5-segmented; stamens ca. 15, filaments subulate, margin villose, anthers ellipsoid; receptacle villose with simple trichomes. Pistillate flowers 6–8 mm long, campanulate, shortly pedicellate; pedicels 2–3 mm long; calyx 4–5 mm long, densely pubescent externally, multiradiate and rosulate trichomes, glabrate internally; calyx lobes 5, united at the base, then free for the terminal 3–4 mm, entire, equal, reduplicate-valvate, triangular, apex acuminate; petals absent; disk flatly 5-lobed; ovary subglobose, covered by finger-like glands; styles 3, multifid, united at the base, each one entire up to 1/3 of their length, then branching into ca. 24 terminal arms, covered by finger-like glands, included in calyx. Fruits 1–1.5 cm long, subglobose, 3-angled, smooth, covered by finger-like glands, calyx lobes conspicuously accrescent, inflated, covering the young fruit; seeds 4–5 mm long, subglobose, ribbed.

Common names: —almizolero, sarna.

Distribution and habitat: — Croton fragrans occurs in moist forests on lower slopes of Andes mountain range in Colombia, Venezuela, and on the Caribbean coast of Colombia and Panama, in dry forests, from sea level to 800 m elevation.

Phenology:— Flowering in January, April–December; fruiting in April–November.

Taxonomic notes: —The species can be easily recognized in the field by its tomentose angled branchlets and deeply lacerate stipules. Among other species of Croton section Cleodora , C. fragrans is most similar to C. fragrantulus , but differs from it by the morphology of the branchlets (angled in C. fragrans vs cylindric in C. fragrantulus ), stipules (broadly ovate and deeply lacerate in C. fragrans vs linear and entire in C. fragrantulus ), calyx lobes of the pistillate flowers (united at the base in C. fragrans vs united up to half of their length in C. fragrantulus ) and styles (multifid in C. fragrans vs 4-fid in C. fragrantulus ).

Some collections of Croton fragrans from Panama were erroneously identified as C. hoffmannii . However, both species can be distinguished by the branchlets (angled in C. fragrans vs cylindric em C. hoffmannii ), stipules (deeply lacerate in C. fragrans vs entire in C. hoffmannii ), pistillate flower aestivation (reduplicate-valvate in C. fragrans vs imbricate in C. hoffmannii ) and calyx lobes in fruits (conspicuously accrescent and inflated in C. fragrans vs inconspicuously accrescent and not inflated in C. hoffmannii ).

Selected specimens examined: — PANAMA. Canal Zone: Espave forest along Albrook-Ft. Clayton dump road, fl., 5 August 1963, J.A. Duke & H. W. Mussell 6624 (MO, WIS) . COLOMBIA. Tolima : Mariquita , 500 m, fl., fr., 9 November 1938, O. Haugth 2426 (COL, MO, US) . VENEZUELA . Ticoporo Forest Reserve , 8º15’N, 70º45’W, 350 m, fr., 15 July 1964, F.J. Breteler 4018 (COL, CUVC, IAN, MBM, MER, MO, US) .

Figures

FIGURE 9. A–E. Croton sexmetralis. A. Flowering branch (Breteler 4575). B. Stipule (Breteler 4575). C. Bract (Breteler 4575). D. Pistillate flower (Breteler 4575). E. Fruit (Breteler 4575). F–K. Croton fragrans. F. Flowering branch, detail of extrafloral nectaries (Léon 192). G. Stipule (Caruzo et al. 136). H. Pistillate flower, gynoecium detail (Liesner & Guariglia 11511). I. Bract (Liesner & Guariglia, 11511). J. Fruit (Breteler 4018). K. Pistillate flower aestivation.