Lavoisiera firmula Martius & Schrank ex Candolle (1828: 104)

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

15. Lavoisiera firmula Martius & Schrank ex Candolle (1828: 104) . Type:— BRAZIL. Minas Gerais: "in Brasiliae montibus excelsis Itambé et Serro Frio" ( Diamantina ), C. F. P. Martius s.n. (holotype: M-0174609-n.v., online image!, photos: CAS!, UEC!, isotype: G-DC-n.v., online image!).

= Lavoisiera firmula var. macrocalyx Cogniaux in Martius (1883: 140). syn. nov. Type:— BRAZIL. Minas Gerais: "in locis saxosis ad Serra da Lapa ” ( Serra do Cipó ), L. Riedel 1318 (holotype: LE!; isotypes: LE!, P!, W!) .

Erect, densely branched shrubs 0.3–1(–2) m tall, essentially glabrous throughout. Branches and branchlets quadrangular to subquadrangular, slightly furrowed longitudinally on opposite faces, sometimes flushed red, defoliating and decorticating basally with age, then becoming subrounded; internodes 6–12 mm long, with knobby thickenings that persist where a leaf has fallen away, nodes with short, red, copious glandular trichomes at adaxial base of blades. Leaves sessile, semi-amplexicaul, spreading to subimbricate and congested on the branchlets distally, sometimes branchlets leafy to the base; blade 15–35 × 6–17 mm, subcoriaceous, elliptic-oblong to elliptic-obovate, base rounded to subauriculate, apex acute and mucronulate, margins entire or rarely subserrulate-ciliate, narrowly subcallose, slightly revolute and flushed pink, flat, pale and glaucous, whitish-green or bluish-green when fresh on both surfaces, sometimes flushed red on the adaxial surface, rarely and anomalously with some (but not all) leaves (Stehmann & Sobral 1137) having a single line of sparse glandular trichomes ca. 1 mm long with each one nestled in small clusters of sessile glands just in from the margin on the abaxial surface, 1–3(–5)-nerved, only the midvein conspicuous. Flowers (5–)6-merous on pedicels 1.5–2 mm long, solitary or in a pseudo-dichasia, at first terminal but becoming central or lateral by the elongation of one or two lateral branches. Bracts subtending the flowers sometimes becoming gradually wider but otherwise similar to or undifferentiated from the principal leaves. Hypanthium (at anthesis) 4–6 × 3–4(–7) mm, oblong-campanulate, slightly granulose and typically fluted (appearing longitudinally striolate), yellowish-green to glaucous; calyx tube ca. 1 mm long with a ring of glandular

LAVOISIERA ( MELASTOMATACEAE )

Phytotaxa 315 (1) © 2017 Magnolia Press • 89 trichomes at the adaxial base, calyx lobes (at anthesis) 2.5–3 × 1.5 mm, triangular, acute, slightly keeled and pungent at the apex, margins entire, glabrous or minutely glandular-puberulent especially at the base adaxially, glabrous abaxially, persistent, pale green abaxially but often pigmented deep red adaxially. Petals 20–25 × 15–20 mm, magenta with a horizontal patch of white at the adaxial base, obovate to subspatulate, apex obtuse to subemarginate, base attenuate, margin inconspicuously glandular-ciliolate. Stamens 10 or 12, dimorphic; large (antesepalous) stamens (5–)6, filaments 10–11 mm long, yellowish-pink, anther thecae 3–4 × 1 mm, oblong, yellow turning brown following pollination, rostrum 0.5 mm long, pedoconnective 6–7 mm long, appendage ca. 1 mm long, yellow, obscurely bilobed; small (antepetalous) stamens (5–)6, filaments 6–7 mm long, anther thecae 3.5–4 × 1 mm, oblong, yellow, rostrum 0.5 mm long, pedoconnective 3–4 mm long, appendage 1–1.5 mm long, rounded to barely lobed, yellow. Ovary 6-locular, 2/3 inferior, style 9 mm long, straight, glabrous, stigma punctiform. Fruiting hypanthium (including calyx lobes) 12–14 × 6–8 mm, strongly constricted above the ovary, greenish-red to brown. Capsule (at maturity) 8–10 mm long, enveloped by the persistent hypanthium and calyx lobes, dehiscing from the base to apex. Seeds 0.74–0.95 × 0.51–0.56 mm, oblong to subreniform, dark grayish-brown, periclinal cell walls of the testa concave (foveolate), raphal zone about 60–70% the length of the seed. Chromosome number unknown.

Illustration:— Figure 36 .

Photographic images:— Figures 2G, H .

Phenology:—Flowering January, June, August and September; the only known fruiting specimens with recorded dates were collected in September.

Distribution and habitat:—Endemic to the Cadeia do Espinhaço of Minas Gerais where it is largely centered on the Serra do Cipó in campo rupestre at 1100–1260 m. Figure 16 .

Conservation status:—This uncommon species is known from a dozen collections, all of which were gathered on the Serra do Cipó. Many of the collection localities are imprecise; we have coordinates only for the single collection we made during field expeditions for this study. We are therefore unable to assess the full extent of its geographic range and local abundance. Future research may warrant threatened status. Until more information is available we regard the status of this species as Data Deficient (DD).

Discussion:— Lavoisiera firmula is a glabrous shrub with flexuous branches that can be copiously leafy to the base. Its leaf blades are comparatively small (15–35 mm long) and the uppermost ones are pale and glaucous, whitish-green to bluish-green when fresh like the hypanthium ( Figure 2G ). The short-pedicellate flowers are modally 6-merous, the petals are a deep magenta with a horizontal band of white at the base, the hypanthium is somewhat lobed or fluted, the calyx lobes are triangular and persistent, and the ovary is 6-locular.

The collections studied are fairly uniform morphologically but some leaves on one collection (Stehmann & Sobral 1137) have a single line of inframarginal glandular trichomes (to 1 mm long) that extend along the basal third or half of the blade on the abaxial surface. Each of these trichomes is nested in a small cluster of sessile glands like those of L. glandulifera and L. harleyi . The shape, color, and glaucous nature of the leaves of Lavoisiera firmula are reminiscent of L. macrocarpa and L. cordata , both of which are also largely restricted to the Serra do Cipó. The former is readily distinguished by its open, divaricately branched habit ( Figure 4A ), prevailingly 8- merous flowers, pink, pink-orange or reddish antesepalous anther thecae ( Figure 4B ), and (7–)8-locular ovary.

Lavoisiera cordata has 6–7-merous flowers and a mostly 6-locular ovary but its petals are creamy white with conspicuous translucent venation ( Figures 2A, C ), its calyx lobes are glandular-ciliolate along the margins, and its calyx lobes are tardily caducous in post-anthesis.

Additional specimens examined:— MINAS GERAIS: Mpio. Santana do Riacho, Serra do Cipó, about 23–24 km from the bridge over the Rio Cipó on the road from Serra do Cipó (formerly Cardeal Mota), about 38 km S of Conceição do Mato Dentro on a temporary detour road while the main Serra do Cipó/Conceição road was being paved, 19˚14’49.3”S, 43˚30’42.7”W, Almeda et al. 9197 (BHCB!, CAS!, MO!, P!, UEC!); Mpio. Santana do Riacho, Serra do Cipó, Damazio 2023 (G!); exact locality not specified, Gardner 4582 (BM!, F!, G!, K!, NY!, P!, US!, W-2!); S. Cabeça de Boi, a 5 km de Itambé, Hensold et al. CFCR 2843 (SPF!, US!); Mpio. Santana do Riacho, Serra do Cipó, P. Oliveira s.n. (RB!); Mpio. Santana do Riacho, Km 134 ao longo da Rodovia Belo Horizonte-Conceição do Mato Dentro, Pinheiro & Esteves CFSC 8569 (CAS!, SPF!, US!); Mpio. Santana do Riacho, Serra do Cipó, ca. Km 130 of Lagoa Santa-Morro do Pilar road, ca. 12 km from Chapéu do Sol, Renner 2128 (CAS!, US!); Mpio. Santana do Riacho, Serra do Cipó, Schwacke 12568 (W!); Mpio. Itambé do Mato Dentro, estrada para a Serra da Cabeça de Boi, Stehmann & Sobral 1137 (CAS!, UEC!); Zuccarini s.n. (M!). MINAS GERAIS?: Blanchet 213 (W!).

90 • Phytotaxa 315 (1) © 2017 Magnolia Press

MARTINS & ALMEDA

Figures

FIGURE 2. Images of Lavoisiera species. A. L. cordata (Almeda et al. 7798). B−C. L. cordata (Almeda et al. 9696). D. L. crassifolia (Almeda et al. 8442). E. L. crassifolia (Almeda et al. 7807). F. L. crassifolia (Almeda et al. 9051). G−H. L. firmula (Almeda et al. 9197). I. L. gentianoides (Almeda et al. 8314). J. L. glandulifera (Almeda et al. 9700). K. L. glandulifera (Almeda et al. 9199). L. L. glandulifera (unvouchered image). Image credits: A−K. Frank Almeda; L. Livia Echternacht.

FIGURE 4. Images of Lavoisiera species. A−C. L. macrocarpa (Almeda et al. 9173). D. L. mucorifera (Almeda et al. 9607). E. L. pulchella (Almeda et al. 9830). F−G. L. pulcherrima (Almeda et al. 9666). H−I. L. punctata (Almeda 9709). J. L. rigida (Almeda et al. 9089). K. L. rigida (Almeda et al. 9604). L. L. rigida (Almeda et al. 9635). Image credits: A−L. Frank Almeda.

FIGURE 16. Distributions of Lavoisiera adamantium, L. firmula, L. humilis, L. pulcherrima, and L. subulata.

FIGURE 36. Lavoisiera firmula. A. Habit. B. Adaxial leaf surface. C. Hypanthium and calyx lobes with enlarged detail of adaxial lobe sinus (right). D. Ovary cross-section. E. Petal with enlarged detail of margin (lower left). F. Ventral view of antesepalous stamen. G. Ventral view of antepetalous stamen. H. Seed. (Based on: A–H, Stehmann & Sobral 1137, UEC.)