Croton campanulatus Caruzo & Cordeiro (2008: 261)

Caruzo, Maria Beatriz Rossi & Cordeiro, Inês, 2013, Taxonomic revision of Croton section Cleodora (Euphorbiaceae), Phytotaxa 121 (1), pp. 1-41 : 6-8

2. Croton campanulatus Caruzo & Cordeiro (2008: 261) ( Fig. 2A–K ). Type:— BRAZIL. Rio de Janeiro: Município de Itatiaia, Parque Nacional do Itatiaia , estrada para a piscina do Maromba , ao longo da estrada, 950 m, 22º26’10’’S, 44º36’49.4’’W, mata atlântica, 6 February 2006, M.B.R. Caruzo, R. Riina & N. Camps 93 (holotype SP!, isotypes K!, NY!, SPF!, WIS!) .

Trees 4–5 m tall; latex reddish; indument rufous-silvery; trichomes lepidote subentire without a central ray, pale, reddish or sometimes with a reddish center and a pale margin; branchlets cylindric, strongly striate, rufoussilvery, covered by reddish and scattered pale trichomes. Leaves discolorous, with a pair of stalked saucershaped acropetiolar glands; lamina 3.5–17.5 × 1.5–9.5 cm, ovate, upper surface green with scattered pale trichomes and lower surface silvery with scattered reddish trichomes or trichomes with a reddish center and a pale margin, apex acuminate, base rounded to truncate, margin entire, upper surface lepidote, lower surface densely lepidote; venation pinnate, brochidodromous; petiole 0.7–9 cm long; stipules 3–5 mm long, linearlanceolate, deciduous. Inflorescence 4–12 cm long, terminal, lax; inflorescence axis appressed, striate, lepidote, rufous-silvery; proximal cymules bisexual, with 1 pistillate flower and 1–2 staminate flowers, distal cymules with ca. 3 staminate flowers; bracts 4–9 mm long, entire, ovate-lanceolate, prophylls 1–2 mm long, lanceolate. Staminate flowers 8–10 mm long, campanulate, pedicels 2–3 mm long; calyx 3–4 mm long, lepidote externally, rufous-silvery, covered by reddish and scattered pale trichomes, glabrate internally; calyx lobes 5, united half of their length, 1.5–2 mm long, entire, equal, valvate, deltate to ovate, apex acute; petals 5 mm long, spathulate, apex obtuse to rounded, lepidote externally; disk 5-segmented; stamens ca. 25, filaments subulate, villose at the base, anthers ellipsoid; receptacle villose with simple trichomes. Pistillate flowers 8–10 mm long, campanulate, not fleshy, sessile to short pedicellate; calyx 7–9 mm long, lepidote externally, rufous-silvery, covered by reddish and scattered pale trichomes, glabrate internally; calyx lobes 5, 7– 9 mm long, equal, quincuncial, broadly ovate, not fleshy, slightly united at the base; petals reduced to ovoid glands; disk entire, deeply 5-lobed; ovary globose, lepidote; styles 3, 4-fid, slightly united at the base, then branching into 12 terminal arms, inserted in calyx. Fruits 10–15 mm long, globose, lepidote, calyx strongly accrescent and inflated, covering the young fruit, pedicel inconspicuously accrescent; seeds 6–8 mm long, globose-elliptic, smooth.

Distribution and habitat: — Croton campanulatus is endemic from Itatiaia massif in Mantiqueira mountains range in southeastern Brazil (Minas Gerais and Rio de Janeiro). It is found along streams and roadsides in montane rain forests of the “Mata Atlântica” domain, at 900–1500 m elevation.

Phenology:— Flowering in January–May, September, November and December; fruiting in April, May, August, November and December.

Taxonomic notes: —Among the species of Croton section Cleodora , C. campanulatus is most similar to C. hemiargyreus Müller Argoviensis (1865: 81) , but they differ by the color of indument, foliar margin, and number of stamens (see table 1). In addition, several herbarium collections of C. campanulatus have been erroneously identified as C. salutaris Casaretto (1845: 89) , another member of C. sect. Cleodora , but the two species can be separated by several floral and vegetative characters (see table 1).

Figures

FIGURE 2. A–K. Croton campanulatus. A. Flowering branch. B. acropetiolar gland. C. lepidote subentire trichomes. D. Pistillate flower. E. Gynoecium detail. F. Disk at the base of the gynoecium. G. Fruit. H. Seed. I. Staminate flower. J. Pistillate flower aestivation. K. Staminate flower aestivation. (Caruzo et al. 93; illustration from Caruzo et al. 2008).