Lavoisiera pohliana O. Berg ex Triana (1871: 30)

Martins, Angela B. & Almeda, Frank, 2017, A Monograph of the Brazilian endemic genus Lavoisiera (Melastomataceae: Microlicieae), Phytotaxa 315 (1), pp. 448-450 : 448-450

28. Lavoisiera pohliana O. Berg ex Triana (1871: 30) . Type:— BRAZIL. Minas Gerais: “in summitate montium inter Rio Jequitinhonha et Columbi,” J. E. Pohl 3162 (D. 1247) (holotype: W!; isotypes: B, destroyed, BM!, BR!, F!- frag., K!, NY!; photos of B isotype: F!, NY!). The two numbers following Pohl’s name enumerated above are on the same collection. These do not represent two syntypes. Many of Pohl’s collections have two numbers, a field number and a number preceded by “D.” which is a separate number from his diary.

= Lavoisiera fragilis Cogniaux ex C. Munhoz & Proença (2000: 60–63) . syn. nov. Type:— BRAZIL. Goiás [Goyaz]: Almocrafe, Serra dos Cristais [Crystaes], 17 Sep. 1895, A. F. M. Glaziou 21312 (holotype: R-000009389, n.v., online image!; isotypes: B, destroyed, BR-552042, n.v., online image!, BR-552048, n.v., online image!, BR-552075, n.v., online image!, BR-550707, n.v., online image!, C!, F!-frag., G!, K!, MPU-013416, n.v., online image!, P-05317655, n.v., online image!, P-05317656, n.v., online image!, RB-00236670, n.v., online image!, S-053233 , n.v., online image!; photos of B isotype: F!, NY!).

Dichotomously branched shrubs 2–2.5 m tall or low, intricately much-branched trees 3 m with trunk diameter up to 12 cm, the bark corky, especially at the base. Branches and branchlets subquadrangular to quadrangular, longitudinally furrowed on opposite faces, sparsely glandular, the glands sessile to very shortly pedicellate, yellowish-green turning to brown, young branchlets leafy to the base, defoliating basally with age, sometimes branches subrounded and grayish in color; internodes 3–5 mm long with knobby thickenings that persist where a leaf has fallen away, nodes with inconspicuous glandular trichomes. Leaves spreading, sessile, somewhat semi-amplexicaul; blade 7–20 × 5–10 mm, rigidly coriaceous, ovate to oblong-ovate or occasionally oblong-elliptic, base rounded to subrounded or attenuate, apex acute to obtuse-acuminate, the apex curved toward the abaxial surface, margin entire, revolute, subcallose, rarely sparsely toothed and shortly glandular-ciliolate, greenish-gray to yellow-green, glabrous on the adaxial surface, sparsely to moderately beset with minute glands on the abaxial surface, the glands sessile, tiny, 0.1 mm long, yellow-orange turning brown, sometimes with a few scattered stalked glandular trichomes 0.5 mm long, inconspicuously to conspicuously reticulate, 3–5-nerved, rarely 1-nerved or 5–7- nerved. Flowers (5–)6-merous, solitary, terminal at ends of branchlets, becoming central by elongation of lateral shoots, sessile. Hypanthium (at anthesis) 4–5 × 4 mm, campanulate, sparsely to moderately covered with small sessile yellowish glands that are rarely mixed with a few gland-tipped trichomes 0.5–0.7 mm long. Calyx tube ca. 1 mm long; calyx lobes (at anthesis) 5–6 × 2.5–3.5 mm, chartaceous to subcoriaceous, caducous in post-anthesis,

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MARTINS & ALMEDA oblong-ovate, acute at the apex, margins glandular-ciliate, cilia 0.1–0.2 mm long, sparsely beset with sessile glands abaxially, glabrous adaxially. Petals 9–25 × 10–18 mm, white but yellow at the base, sometimes tinged with pink in bud, obovate to spatulate, apex asymmetrically truncate, base attenuate, margin eciliate or shortly glandular-ciliate at the apex. Stamens 10 or 12, dimorphic; large (antesepalous) stamens (5–)6, filaments 7–8 mm long, anther thecae 5–5.5 × 0.8 mm, linear-oblong to oblong, yellow to reddish, rostrum 0.5 mm long, pedoconnective ca. 10 mm long, appendage 1.5–2 mm long, slightly emarginate and bilobed, yellow; small (antepetalous) stamens (5–)6, filaments 6–7 mm long, anther thecae 4.5–5 × 0.8 mm, linear-oblong to oblong, yellow, rostrum 0.5 mm long, pedoconnective 2–3 mm long, appendage 1 mm long, truncate to obscurely bilobed, yellow. Ovary (5–)6-locular, 2/ 3 inferior, style 12–16 mm long, glabrous, slightly curved apically, stigma punctiform. Fruiting hypanthium (not including the caducous calyx lobes) ca. 6 mm long, typically thick and woody. Capsule (at maturity) 6–12 × 6–12 mm, globose to urceolate, woody, light brown, enveloped by the persistent and enlarged woody hypanthium, dehiscing from the apex to the base. Seeds 1.14–2.04 × 0.70–0.82 mm, reniform to angular-obovoid, orangish-red, periclinal cell walls of the testa concave (foveolate), raphal zone about 40–60% the length of the seed. Chromosome number unknown.

Illustration:— Figure 51 ; Munhoz & Proença (2000: 61, Figure 1 , as L. fragilis ).

Phenology:—Flowering January through March and October through December and surely other months; fruiting in February, March, June, September, November, December and probably other months as well.

Distribution and habitat:—The type was collected in eastern Minas Gerais over 140 years ago. One recent collection made in 2006 is known from south of the type locality. This species now appears to be largely restricted to Goiás where all recent collections come from the Serra dos Cristais and Linda Serra dos Topázios (município Cristalina) in rocky cerrado and campo rupestre at 1000–1215 m elev. Figure 33 .

Conservation status:—Some 14 collections of this local species are known to us, most of which were gathered on the Serra dos Cristais. The EOO is 179 km ² and the AOO is 16 km ². Only the population occurring in the private 500 hectare Reserva Particular do Patrimônio Natural Linda Serra dos Tapázios is afforded protection ( Munhoz & Proença 2000). Urbanization, crystal and topaz extraction, and potential fires pose the greatest threats to the habitat preservation of this species. We propose a classification of Endangered (EN): B1ab(iii).

Discussion:—Of the few species of Lavoisiera that can become small trees with a trunk diameter up to 12 cm, only L. pohliana consistently has white flowers. It also has rigidly coriaceous leaf blades that are glabrous adaxially and moderately beset with minute, mostly sessile yellow-orange glands (these often become brown) mostly 0.1 mm long abaxially. This glandular indumentum also occurs on the margins and abaxial surfaces of the apically acute calyx lobes and on the hypanthia. Among the species of Lavoisiera that commonly produce white flowers, L. pohliana is one of two species with prevailingly 6-merous flowers and 6-locular ovaries. The other species is the more widespread L. grandiflora which differs by it larger leaf blades [20–45(–80) × 10–20(–40) mm] that are 7–9-nerved, pedicellate flowers (vs. sessile flowers), persistent calyx lobes, and much larger fruiting hypanthia (25–30 mm) that are conspicuously constricted distally below the torus.

When Munhoz and Proença (2000) validated Cogniaux’s L. fragilis , they compared it to L. pohliana and noted that the latter differed in having a shrubby habit (vs. a tree), persistent calyx lobes in fruit (vs. caducous), and a distribution restricted to the type locality in Minas Gerais. We have compared the type of L. pohliana with the types and several of the paratypes of L. fragilis cited by Munhoz and Proença and find that they are a good match in all details. The habit and calyx lobe characters that they emphasized are not diagnostic since L. pohliana can become a small tree and its calyx lobes are in fact caducous in fruit. Because we cannot find diagnostic characters to circumscribe L. fragilis , we see no compelling rationale to recognize it and here relegate it to synonymy.

Lavoisiera pohliana appears to be closest to L. daviesiana , a new species described here from Minas Gerais and known from few collections. The latter has white petals, 6-merous flowers, and a 5-locular ovary. It also has minute sessile yellowish-orange glandular trichomes but they occur on both leaf surfaces (vs. just the abaxial surface) as well as on both surfaces of the calyx lobes (vs. the abaxial surface only). The leaf apex of L. daviesiana is obtuse to somewhat rounded ( Figure 35B ), the bracts subtending the flowers differ in shape and have a flattened petiole ( Figure 35C ) ca. 1 mm long (vs. sessile), and the calyx lobe margins are beset with stiff evenly spaced eglandular spreading trichomes 0.5–0.7 mm long ( Figure 35D ).

LAVOISIERA ( MELASTOMATACEAE )

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Additional specimens examined:— GOIÁS: Mpio. Cristalina, 4 km N of Cristalina off of the main highway (BR 050), -16.73840, -47.61770, Almeda et al. 9423 (CAS!, UEC!); Serra dos Cristais, Glaziou 21312 (C!, K!, LE!, P!); Mpio. Cristalina, RPN-Linda Serra dos Topázios , 16°44'S, 47°41'W, Guimarães s.n. (CAS!); Mpio. Cristalina, Serra dos Cristais, Hatschbach & Kasper 41683 (C!, MBM!, MO!, NY!, UEC!, US!); Mpio. Cristalina, Serra dos Cristais, Hatschbach & Kummrow 46605 (F!); Mpio. Cristalina, Serra dos Cristais , estrada para Salto do Arrojado, Hatschbach et al. 66118 (ESA!, HUEFS!); Mpio. Cristalina, ca. 5 km S of Cristalina, 17°S, 48°W, Irwin et al. 9738 (CAS!, MO!, NY!, UB!, US-2!); Mpio. Cristalina, ca. 2 km N of Cristalina, 17°S, 48°W, Irwin et al. 13296 (CAS!, MO!, NY!, UEC!, US-2!); Mpio. Cristalina, estrada de terra para Brasília, em frente à estação de luz, Koschnitzke & Matsumoto 35624 (UEC!): Mpio. Cristalina, ca. 4 km N of Cristalina of E side of BR 50, Kral et al. 75908 (NY!, US!); Mpio. Cristalina, RPPN-Linda Serra dos Topázios , 17°0'S, 48°0'W, R. Oliveira et al. 285 (K!,

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MARTINS & ALMEDA

NY!); Mpio. Cristalina , ca. 5 km da cidade, estrada para Paracatu , 16°46'S, 47°37'W, Pirani et al. 1552 ( US!); Mpio. Cristalina, estrada Cristalina-Marajó, 16°45’S, 47°36’W, Romero et al. 5509 ( HUFU, UEC!) : Mpio. Cristalina , ca. 4 km N de Cristalina , lado leste da Rodovia BR 50 em direção a Brasília , Wanderley 1876 ( CAS!, IAC, SP) ; MINAS GERAIS: Diamantina, Cia Suzano Celulose-Gleba A (Buritis) , Vidal 444 (BHCB!).

Figures

FIGURE 1. Images of Lavoisiera species. A. L. adamantium (Almeda et al. 8504). B–C. L. alba (Almeda et al. 9624). D–E. L. arachnoidea (unvouchered image). F. L. belinelloi (Almeda et al. 8532). G. L. bradeana (Almeda et al. 9718). H. L. canastrensis (Almeda et al. 7878). I. L. caryophyllea (Almeda et al. 9172). J–K. L. chamaepitys (Almeda et al. 8500). L. L. confertiflora (Almeda et al. 9725). Image credits: A–C, F–L. Frank Almeda; D–E. Karina Fidanza.

FIGURE 33. Distributions of Lavoisiera cordata, L. gentianoides, L. grandiflora, L. pohliana, and L. setosa.

FIGURE 35. Lavoisiera daviesiana. A. Habit. B. Abaxial leaf surface with detail of revolute margin (left). C. Abaxial bract surface. D. Hypanthium and calyx lobes at anthesis (petals removed) with enlarged surface detail (lower right). E. Stamens (ventral view), antesepalous (left) and antepatalous (right). F. Flower. (A–F, Hatschbach et al. 66393, MBM.)

FIGURE 51. Lavoisiera pohliana. A. Habit. B. Abaxial bract surface. C. Flower. D. Hypanthium and calyx lobes with enlargement of calyx lobe margin (upper right) and hypanthial surface (lower right). E. Ovary cross-section. F. Petal with enlargement of margin detail (lower right). G. Ventral view of antesepalous stamen. H. Ventral view of antepetalous stamen. I. Seed. (Based on: A–B, Koschnitzke & Matsumoto 35624, UEC; C–H, Irwin et al.13296, UEC; I, Romero et al. 5509, UEC.)