Eremanthus ovatifolius Loeuille & Pirani, 2016

Loeuille, Benoît & Pirani, José Rubens, 2016, Two new syncephalous species of Eremanthus (Asteraceae: Vernonieae) from southeastern Brazil, Phytotaxa 243 (2), pp. 128-136 : 132-135

Eremanthus ovatifolius Loeuille & Pirani , sp. nov. ( Fig. 1 , 4 )

Species Eremantho erythropappo simile, sed foliis ovatis interdum obovatis (nec oblanceolatis nec ellipticis) et capitulis inter 1/4 ad dimidio pro longitudinem connatis (non dimidio ad per totam longitudinem) differt.

Type:— BRAZIL. Minas Gerais: Alvarenga, Pico da Aliança, 19° 24’ 06.74” S, 41° 40’ 35.02” W, 996 m, fl. fr., 4 August 2014, B. Loeuille et al. 898 (holotype: SPF!, isotypes: BHCB!, K!, MBM!, P!, RB!, SP!, US!).

Treelet up to 2.5 m; bark fissured longitudinally. Stems branched in upper part, formerly leafy, later becoming leafless, brown-greyish lepidote with triangular leaf-scars following leaf falls, younger branches frequently flattened and furrowed. Leaves alternate, simple; petiole 0.4–1.9 cm long, strongly discolorous; blade ovate, sometimes obovate, 2.7–7 × 1.3–3.8 cm, venation brochidodromous, midrib prominent abaxially, sometimes slightly furrowed, adaxially glabrate, lepidote when young, abaxially dirty white, densely lepidote, tomentum of branched, 3- to 5-armed, bladder-like trichomes, subcoriaceous to coriaceous, margins entire, flat, apex obtuse or slightly acute, base acute, sometimes asymmetrical. Capitula fused in a syncephalium (secondary order inflorescence), organized in a terminal compound cyme of 8–30 syncephalia. Syncephalium 7.8–10.9 mm tall, 8.2–14.3 mm in diam., hemispherical; bracteoles 1–2, 3.2–8 mm long, leaf-like, ovate; secondary bracts ovate, dirty white to stramineous, sometimes upper part leaf-like, densely tomentose, 2–4 mm long. Capitula 4–17, homogamous, discoid, sessile, fused for 1/4–1/2 of their length; involucre 3.2–5.3 mm tall, 1.7–3 mm in diam., 4–5-seriate, obconical; outer phyllaries ovate or obovate, 1.6–3.7 × 0.7–1.3 mm, imbricate, greenish, upper half purple, apex obtuse, sometimes apiculate, densely tomentose to lanulose; inner phyllaries lanceolate or oblanceolate, 4–5.6 × 0.9–1.1 mm long, loosely imbricate, margins scarious, greenish or purple, glabrescent, apex acute, frequently apiculate, tomentulose, purple; receptacle convex, with some isolated fimbriae to c. 0.5 mm. Florets 3–4 per capitulum, bisexual, fertile; corollae actinomorphic, deeply 5-lobed, white to lilac, glandular-punctate, corolla tube 2.3–4.1 × 0.7–1.1 mm, glabrous, corolla lobes 2.4–3.2 × 0.5–0.7 mm, glandular-punctate, glabrescent, apex acute; anther whitish or lilac, apical anther appendages trullate, acute, anther base sagittate, acute; style shaft 4.2–5.5 mm long, white or pale lilac, glabrous throughout except for pubescent upper 0.6–1 mm beneath style-arms, style-arms 1.1–3 mm long, apex acute, pubescent outside, hairs acute, style-base glabrous, lacking basal node. Cypsela (immature) cylindrical to turbinate, 1.35–1.65 × 0.6–0.9 mm, strongly 10-ribbed, glabrous, densely glandular-punctate; carpopodium minute; pappus setae 3–4-seriate, purple or white, setose, deciduous, ± barbellate, frequently slightly twisted throughout length, outermost series 1–3.3 mm, innermost series 4.1–5.4 mm.

Distribution: —This species is currently known only from Pico da Aliança in the middle area of the Doce River Valley, Minas Gerais state, southeastern Brazil ( Fig 3 ). It grows in campos rupestres, which are open formations on rocky to sandy soils, at elevations of 900–1430 m.

Conservation Status: —The species is known from a single locality and population, which is not situated within any protected area. Although locally abundant, with up to 200 individuals, the species is restricted to Pico da Aliança, and absent from Pico do Padre Angelo, a nearby locality with the same type of habitat. It presents AOO = 8 km 2 and one known location. Considering the use attributed to the species (wood used for small bridge construction because it does not rot easily), it results in a continuing decline of the area of occupancy, quality of habitat, subpopulations and number of mature individuals. According to criteria B2ab (ii, iii, iv, v) ( IUCN 2014), this species is considered critically endangered (CR) ( Negrão 2015b).

Etymology: —The specific epithet refers to the ovate leaves of the new species.

Additional specimens examined (paratypes): — BRAZIL. Minas Gerais: Alvarenga, Pico da Aliança , 9 July 2014, 19° 23’ 43.22” S 41° ‘40’ 08.93” W, 1430 m, Gonella et al. 700 ( SPF!) ; ibid., 4 August 2014, 19° 23’ 47.98” S, 41° 40’ 19.65” W, 1300 m, Loeuille et al. 903 ( SPF!, US!).

Discussion: —The new species belongs to Eremanthus sect. Vanillosmopsis because of its obconical heads partially fused into a syncephalium and glabrate cypselae with frequently twisted deciduous pappus. Only two other species of Eremanthus also display ovate leaves: E. auriculatus MacLeish & Schumacher (1984: 86) and E. hatschbachii Robinson (1995: 390) . The new species differs from E. auriculatus by its acute leaf bases (vs. auriculate), heads with 3–4 florets (vs. one) and glabrous cypselae with setose deciduous pappus (vs. pubescent cypselae with paleaceous persistent pappus). From E. hatschbachii the new species is distinct in its larger leaves (2.7–7 vs 0.9–1.5 cm long.) and heads fused into a syncephalium (vs. a glomerule without a tissue fusion). Moreover, E. auriculatus is restricted to Goiás and Mato Grosso states and E. hatschbachii is endemic to Mucugê (Bahia state). The new species co-occurs at lower altitudes of Pico da Aliança (Minas Gerais state) with E. erythropappus and E. incanus ( Lessing 1829: 342) Lessing (1831: 682) ; both species display oblanceolate to elliptic leaves (vs. ovate) and syncephalia with a higher degree of heads fusion (from 1/2 to nearly entire length vs. 1/4 to 1/2 of their length). So far no morphological intermediates have been found in field that would indicate putative hybrids between these species. The Pico da Aliança is located in a poorly collected region, and several species of angiosperm families as Asteraceae , Droseraceae , Orchidaceae and Bromeliaceae have been recently described from this peak or from the proximate Pico do Padre Angelo ( Campacci 2014, Gonella et al. 2015, Leme et al. 2013, 2014). However, E. ovatifolius is absent from the latter peak.

Key to Eremanthus

The following key is based on the interactive multi-entry key available at http://www.xper3.fr/xper3GeneratedFiles/ publish/identification/-4671204629593634295/mkey.html; this digital key also contains pictures of live and dried parts of each species of Eremanthus , mostly of the characters used in the key.

1. Heads fused in syncephalium (secondary receptacle, frequently with secondary bracts)..................................................................2

- Heads solitary or in glomerule, sometimes slightly appressed basally but without secondary receptacle......................................14

2. Stem indument felted..........................................................................................................................................................................3

- Stem indument tomentose................................................................................................................................................................10

3. Cypsela glabrous; pappus setose........................................................................................................................................................4

- Cypsela pubescent; pappus subpaleaceous to paleaceous..................................................................................................................7

4. Involucre obconical; florets 3–4 per head..........................................................................................................................................5

- Involucre cylindrical; floret 1 per head ...................................................................................................................... E. polycephalus

5. Heads fused for 1/4–1/2 of length......................................................................................................................................................6

- Heads fused more than 1/2 of length........................................................................................................................ E. erythropappus

6. Leaves elliptic to lanceolate, rarely narrowly ovate, base attenuate (Rio de Janeiro and São Paulo states)............. E. praetermissus

- Leaves ovate, sometimes obovate, rarely elliptic, base acute (Minas Gerais state)....................................................... E. ovatifolius

7. Syncephalium hemispherical; heads fused less than 1/2 of length.....................................................................................................8

- Syncephalium spherical; heads fused more than 1/2 of length..........................................................................................................9

8. Leaf blades 6–16 cm long; heads fused 1/4–1/2 of length; pappus deciduous ...................................................... E. mattogrossensis

- Leaf blades 2–7 cm long; heads fused up to 1/4 of length; pappus persistent ............................................................ E. rondoniensis

9. Leaf blades green to dark green; pappus subpaleaceous and deciduous (Bahia and Minas Gerais states)......................... E. incanus

- Leaf blades silvery; pappus paleaceous and persistent (Goiás state) ............................................................................... E. argenteus

10. Syncephalium hemispherical............................................................................................................................................................11

- Syncephalium spherical....................................................................................................................................................................13

11. Heads fused more than 1/2 of length................................................................................................................................................12

- Heads fused 1/4–1/2 of length.................................................................................................................................... E. glomerulatus

12. Secondary bracts small, inconspicuous, not surrounding each syncephalium; involucre ovoid.................................... E. goyazensis

- Secondary bracts large and conspicuously surrounding each syncephalium; involucre obconic ........................................ E. cinctus

13. Shrub; leaves oblong to lanceolate; heads fused more than 1/2 of length; pappus biseriate................................................. E. mollis

- Treelet or tree; leaves trullate to ovate; heads fused 1/4–1/2 of length; pappus 3–5-seriate......................................... E. auriculatus

14. Leaf blades silvery............................................................................................................................................................................15

- Leaf blades green to dark green........................................................................................................................................................17

15. Leaf blades 2–2.5 cm long; cypsela glabrous; pappus setae twisted.............................................................................. E. brevifolius

- Leaf blades 3–12 cm long; cypsela pubescent; pappus setae straight..............................................................................................16

16. Stem indument felted; involucre cylindrical; florets 3–4 per head; pappus setose and persistent .................................. E. elaeagnus

- Stem indument tomentose; involucre campanulate; florets 8–11 per head; pappus paleaceous and caducous to deciduous .............. ................................................................................................................................................................................... E. veadeiroensis

17. Treelet or tree; leaf blades membranaceous to subcoriaceous, 2.4–8.3 cm long; pappus 3–5-seriate.............................................18

- Shrub; leaf blades coriaceous, 0.9–1.5 cm long; pappus biseriate .............................................................................. E. hatschbachii

18. Floret 1 per head; involucre always cylindrical...............................................................................................................................19

- Florets 3–5 per head; involucre obconic, rarely cylindrical.............................................................................................................20

19. Heads 3–9 per glomerule; phyllaries apically purple ........................................................................................................ E. uniflorus

- Heads 1–2 per glomerule; phyllaries apically brown .................................................................................................... E. brasiliensis

20. Heads 2–4(–5) per glomerule; apices of phyllaries brown (Ceará state) .......................................................................... E. arboreus

- Heads 6–9 per glomerule; apices of phyllaries purple (Bahia, Goiás, Minas Gerais, Pernambuco and Sergipe states)...................... ........................................................................................................................................................................................... E. capitatus

Figures

FIGURE 1. Eremanthus praetermissus. A. Flowering branch. B. Corolla, androecium and style. C. Cypsela and pappus. D. Leaf, abaxial surface. E. Syncephalium. Eremanthus ovatifolius. F. Flowering branch. G. Leaf, abaxial surface. H. Syncephalium. A–E. Loeuille et al. 830 (SPF). F–G. Loeuille et al. 898 (SPF).

FIGURE 3. Distribution of Eremanthus erythropappus (blue circle), E. praetermissus (red triangle) and E. ovatifolius (yellow star).

FIGURE 4. Eremanthus ovatifolius. A. Syncephalium, lateral view. B., C., D. Flowering branch. E. Habit. A.–E. by B. Loeuille.