Dendrophorbium capixabense J. Calvo & Roque, 2018

Calvo, Joel & Roque, Nádia, 2018, Dendrophorbium capixabense (Compositae, Senecioneae), a new species from Espírito Santo, Brazil, Phytotaxa 344 (1), pp. 47-52 : 48-51

Dendrophorbium capixabense J. Calvo & Roque , sp. nov. ( Fig. 1 , 2 )

Type: — BRAZIL. Espírito Santo: Vargem Alta, Morro do Sal , lower areas of the valley slopes near the village, 20º41’07’’S 41º00’23’’W, 610 m, 5 Aug 2017, J. Calvo 7568 (holotype: RB 743008 ; isotypes: ALCB 129285 , BHCB, MBML, NY, SPF, US).

Species morphologically similar to D. bradei and D. fruticosum . From the former it can be distinguished by the glabrous leaf abaxial surface, the glabrescent synflorescence branches with uppermost synflorescence bracts linear and not foliose, and by having 8(–10) involucral bracts, 5(–8) ray florets, and linear supplementary bracts. It differs from the latter in having the leaf margin denticulate only on the upper two thirds and in the striking violaceous color of the leaf abaxial surface.

Shrub 2–6 m tall, not branched or only at the upper part. Stem fistulous, up to 2 cm diam. at the base, terete, violaceous, glabrous, with leaves only on the upper part as time passes. Leaves lanceolate, subcoriaceous; lamina 9–18.5 cm long, 3–5.9 cm wide, apex acute, base cuneate to attenuate, finely dentate on the upper two thirds, glabrous on both faces, green above (usually with violaceous venation), violaceous beneath; petiole 0.5–1.9 cm long. Synflorescence corymbiform, with bracts similar to the upper cauline leaves that strongly decrease in size upwards and become linear; synflorescence branches glabrescent, violaceous. Capitula heterogamous, radiate, on pedicels 2–4.5 cm long, glabrescent. Involucre ca. 4.5 mm in diam., ca. 9 mm long, cylindrical; involucral bracts 8(–10), 7–7.5 mm long, 1.5–3 mm wide, linear, glabrous, green and violaceous at the apex; supplementary bracts 4–6, 2–3 mm long, 0.6–0.8 mm wide, linear to slightly subulate, almost a third as long as involucral bracts, glabrous, usually violaceous. Ray florets 5(–8), female, 14–18 mm long (limb 9–12 mm long, 3–3.5 mm wide, 3-toothed at the apex), yellow; disc florets 13–16(–22), bisexual, 8–9 mm long, 5-lobed, yellow; style branches truncate with sweeping-hairs at the apex; filament collar balusterform; anther bases caudate, almost as long as the filament collar. Achenes glabrous (mature ones not studied); pappus ca. 6 mm, rather persistent, whitish. Chromosome number: unknown.

Distribution and habitat: —Species known from the surroundings of Vargem Alta and Castelo (Cachoeiro de Itapemirim, southern Espírito Santo). It grows in Atlantic ombrophilous dense forest remnants, between elevations of 600–1700 m.

Phenology: —Flowering from July to August.

Etymology: —The epithet derives from the term capixaba, which comes from the Tupi indigenous language and was used by the natives to name corn and manioc plantations. Consequently, the settlers from Vitoria began to apply the word capixaba to the natives living in the region, which later became a popular gentilic for anyone born in Espírito Santo State. Montanhas Capixabas is the Portuguese name of the mountainous region where this species thrives in.

Additional specimens examined (paratypes): — BRAZIL. Espírito Santo: Castelo, Braço do Sul , 20º28’S 41º04’W, 6 Aug 1948, A. C. Brade 19151 ( RB) ; Castelo, Forno Grande , região elevada, 12 Aug 1948, A. C. Brade 19257 ( RB) ; Cachoeiro do Itapemirim, Vergem Alta, Morro do Sal , 21 Aug 1948, A. C. Brade 19333 ( RB) ; Cachoeiro do Itapemirim , July 1950, J. de Nascimento s.n. ( RB 70728 ) ; Cachoeiro do Itapemirim, Vergem Alta, Morro do Sal , 16 Aug 1981, V. F. Ferreira 1831 ( MBM) ; Castelo, Parque Estadual do Forno Grande, Pico do Forninho , 20º31’S 41º05’W, 7 Aug 2013, R. C. Forzza et al. 7663 ( VIES) ; Castelo, Parque Estadual do Forno Grande, afloramento por baixo do Mirante , 20º30’S 41º05’W, 16 July 2008, L. Kollmann & A. P. Fontana 11087 ( RB) ; Castelo , distrito de Forno Grande, trilha para piscinas, 20º30’S 41º05’W, 17 July 2008, M. M. Saavedra et al. 785 ( RB) ; Castelo, distrito de Forno Grande, localidade Balança , 20º31’S 41º06’W, 18 July 2008, M. M. Saavedra et al. 806 ( RB) .

Discussion: —Herbarium specimens studied at RB revealed that the new species was widely misidentified as D. bradei , a species described from Serra dos Orgãos (Rio de Janeiro State). However, several characters let anyone to easily realize that the specimens from Montanhas Capixabas correspond to a distinct species. These characters are the indumentum of the leaf abaxial surface, type of synflorescence, indumentum of synflorescence branches, and type of synflorescence bracts, as well as the number of involucral bracts, number of ray florets, and shape and size of supplementary bracts.

Dendrophorbium capixabense has the leaf abaxial surface glabrous, even when young ( Fig. 2D ), whereas those of D. bradei have a lax arachnoid indumentum beneath that usually become glabrescent as time passes. The synflorescence is corymbiform in D. capixabense ( Fig. 1A ) and paniculiform in D. bradei . Since the capitula of this latter species have shorter pedicels (1–2.2 cm long vs. 2–4.5 cm long in D. capixabense ), its synflorescence is also clearly more congested. The indumentum of the synflorescence branches and pedicels is another useful character (glabrescent in D. capixabense vs. densely arachnoid in D. bradei ), as well as the uppermost synflorescence bracts (reduced, linear, and glabrous or almost so in D. capixabense vs. foliose, lanceolate, with arachnoid trichomes on the margins in D. bradei ). The architecture of the capitulum is also distinctive; D. capixabense displays lower number of involucral bracts (8(–10) vs. 12–14 in D. bradei ), which are shorter (7 − 7.5 mm long vs. 9 − 9.5 mm long), and lower number of ray florets (5(–8) vs. 12–14). The supplementary bracts are linear and glabrous or almost so in D. capixabense , while those of D. bradei are bigger (3–7 × 1.2–2.5 mm vs. 2–3 × 0.6–0.8 mm), lanceolate, with arachnoid indumentum on the margins (see Fig. 3 for comparing characters of the involucre). It also has to be noted that in D. capixabense is very characteristic the violaceous color of the stem, synflorescence branches, and leaf abaxial surface ( Figs. 1A , 2 D-E-F). This character is very striking on living plants, but less noticeable on dry specimens. On the basis of the studied dry specimens of D. bradei , it does not seem that they have the mentioned violaceous coloration.

Dendrophorbium fruticosum is another similar species from southeastern Brazil, cited by Cabrera (1957) from Rio de Janeiro and Espírito Santo. However, the specimens from the latter state are misidentified and should be placed under the new species. Dendrophorbium fruticosum also displays subcoriaceous glabrous leaves, corymbiform synflorescence, ca. 8 involucral bracts, and 5–6 ray florets. These species can be differentiated by the leaf margin (dentate almost along the whole margin vs. denticulate only on the upper two thirds in D. capixabense ), and the color of the leaf abaxial surface (greenish vs. violaceous in D. capixabense ).

Figures

FIGURE 1. Dendrophorbium capixabense. A. Upper part of the plant. B. Synflorescence. Pictures from the type locality.

FIGURE 2. Dendrophorbium capixabense.A. Capitulum.B. Detail of the involucre, supplementary bracts, and uppermost synflorescence bracts. C. Leaf adaxial surface. D. Leaf abaxial surface. E. Petioles. F. Basal part of the stem. G. Stem section at the basal part. Pictures from the type locality.

FIGURE 3. Characters of the involucre. A. Dendrophorbium capixabense. B. Dendrophorbium bradei. Ib. Involucral bracts. Sb. Supplementary bracts.Arrows show the indumentum of the pedicels, glabrescent in D. capixabense vs. arachnoid in D. bradei.