Croton organensis Baillon (1864: 324)

Caruzo, Maria Beatriz Rossi & Cordeiro, Inês, 2013, Taxonomic revision of Croton section Cleodora (Euphorbiaceae), Phytotaxa 121 (1), pp. 1-41 : 12-14

publication ID

https://doi.org/ 10.11646/phytotaxa.121.1.1

persistent identifier

https://treatment.plazi.org/id/03EC87F5-FFE4-0378-FF11-BE84FDC0FDF6

treatment provided by

Felipe

scientific name

Croton organensis Baillon (1864: 324)
status

 

5. Croton organensis Baillon (1864: 324) View in CoL ( Fig. 5A–C View FIGURE 5 ). Type:— BRAZIL. Rio de Janeiro: Serra dos Orgãos ,

May 1839, J.B.A. Guillemin cat. 938 (holotype P[00634527]!).

Croton platycladus Müller Argoviensis (1865: 123) View in CoL . Type :— BRAZIL. Bahia: 1832, J. Lhotsky s.n. (lectotype G-DC!, here designated); Bahia: s.dat., A.M.A.C. Limminghe s.n. (syntype G-DC!).

Croton oxyphyllus Müller Argoviensis (1873: 100) View in CoL . Type:— BRAZIL. Rio de Janeiro: “in silvis primaevis prope Bananal, 800–1000 ped. supra maré”, s.dat., C.F.P. von Martius 318 (holotype M!).

Trees 4–15 m tall; latex clear; simple, stellate and dendritic trichomes; branchlets strongly flattened, striate, floccose, covered by dendritic trichomes. Leaves discolorous, with a pair of sessile basilaminar glands, inconspicuous and maculate, greenish, covered by stellate trichomes; lamina 7–26(30) × 2.5–10 cm, ovatelanceolate to elliptical, apex acuminate to long acuminate, rarely acute, base subcordate, obtuse to cuneate, margin irregularly serrate, with glands; upper surface pubescent with scattered simple trichomes, stellate trichomes concentrated in midvein, lower surface pubescent, pale, stellate trichomes; venation pinnate, eucamptodromous, secondary veins parallels between them; petiole ca. 2.5 cm long; stipules linear, ca. 1 cm long. Inflorescences 7–22 cm long, terminal, lax, pendant; inflorescence axis flattened, striate; proximal cymules bisexual, with 1 pistillate flower and 1 staminate flower, distal cymules with ca. 2 staminate flowers; bracts entire, linear-lanceolate, ca. 5 mm long, prophylls linear, inconspicuous. Staminate flowers ca. 1.5 cm, subcampanulate, long pedicellate; pedicel ca. 7 mm long; calyx ca. 5 mm long, pubescent externally, greenish-white, stellate trichomes, glabrate internally; calyx lobes 5, united at the base, ca. 4 mm long, entire, equal, valvate, rhomboidal, apex acute to obtuse, margin villose; petals ca. 4 mm long, oblong, apex obtuse, margin villose; disk 5-segmented; stamens ca. 15; filaments filiform, villose at the base, anthers globoseellipsoid; receptacle villose with simple trichomes. Pistillate flowers ca. 1.5 cm long, flask-shaped, pedicellate; pedicels 2–3 mm long; calyx ca. 7 mm long, pubescent externally, ferrugineous at the base, greenish at the apex, stellate trichomes, glabrate internally; calyx lobes 5, ca. 6 mm long, united at the base, entire, equal, quincuncial, rhomboidal, apex obtuse; petals absent; disk 5-segmented; ovary globose, pubescent, stellate trichomes; styles 3, multifid, united into a short column at the base, each one entire half of their length, then branching into ca. 24 terminal arms, exserted from calyx. Fruit ca. 2.5 cm long, ellipsoid, smooth, pubescent; calyx lobes inconspicuously accrescent; seeds ca. 1 cm long, subglobose, ribbed.

Distribution and habitat: —This species occurs in southeastern Brazil, in the states of Minas Gerais, Rio de Janeiro, and São Paulo, in montane rain forests, located at Serras do Mar and Mantiqueira, at 800– 300 m elevation. The collection from the state of Bahia, the lectotype of C. platycladus , would represent an unusual disjunct pattern. However, we found no other collections from Bahia, an indication that perhaps the given locality of the type collection is not correct.

Phenology:— Flowering in October and December; fruiting in January, February, March, April, November and December.

Taxonomic notes: — Croton organensis grows in sympatry with other arborescent species of C. sect. Cleodora , namely C. campanulatus and C. salutaris . However, it is distinguished from them due to its indument (stellate in C. organensis vs lepidote in C. campanulatus and C. salutaris ), leaves (ovate-lanceolate to elliptical in C. organensis vs ovate in C. campanulatus and C. salutaris ) and venation pattern (eucamptodromous in C. organensis vs brochidodromous in C. campanulatus and C. salutaris ).

Most herbaria collections of Croton organensis were lacking staminate flowers in their proximal cymules, because they soon wither and fall. Nevertheless, in the field we have found individuals with bisexual proximal cymules.

Selected specimens examined: — BRAZIL. São Paulo: Campos do Jordão , fl., 26 October 2004, M.B.R. Caruzo et al. 72 (SP, SPF, WIS) .

WIS

University of Wisconsin

Kingdom

Plantae

Phylum

Tracheophyta

Class

Magnoliopsida

Order

Malpighiales

Family

Euphorbiaceae

Genus

Croton

Loc

Croton organensis Baillon (1864: 324)

Caruzo, Maria Beatriz Rossi & Cordeiro, Inês 2013
2013
Loc

Croton oxyphyllus Müller Argoviensis (1873: 100)

Muller Argoviensis, J. 1873: )
1873
Loc

Croton platycladus Müller Argoviensis (1865: 123)

Muller Argoviensis, J. 1865: )
1865
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