Lavoisiera senae Schwacke (1900: 3)

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

Phytotaxa 315 (1) © 2017 Magnolia Press • 161 37. Lavoisiera senae Schwacke (1900: 3) . [“ Senaei ”]. Type:— BRAZIL. Minas Gerais: “in cacumine montium Serra do Cipó prope Conceicão do Serro, ubi rarissima,” Aug. 1895, J. C. Sena s.n. (Herb. Schwacke 11753) (holotype B, destroyed; lectotype, here designated: RB-40728!, photo, F!; isolectotypes: BR-552889!, P!; photos of B holotype: F!, NY!).

Erect, densely branched shrubs 0.5–1 m tall. Branches and branchlets slender, quadrangular and shortly winged distally to subrounded, furrowed longitudinally on opposite faces, glabrous, defoliating basally with age or sometimes the branchlets leafy to the base; internodes 2–7 mm long, with knobby thickenings that persist where a leaf has fallen away, nodes with inconspicuous glandular trichomes. Leaves sessile or tapering gradually into a poorly defined, flattened petiole up to 1 mm long, spreading on the uppermost branchlets, not imbricate and not concealing the internodes; blade 15–20(–30) × 2–4 mm, linear-oblong to ensiform, base attenuate, apex acute and terminating in a pungent trichome 2.5–3 mm long, margins narrowly and inconspicuously subcallose, entire or obscurely subserrulate, sparsely beset with spreading trichomes 2.5–3.5 mm long, glabrous on both surfaces except for a few long trichomes along the midrib abaxially, greenish-gray or yellowish-green when dry, flat, essentially 1- nerved to inconspicuously 3-nerved. Flowers 6-merous, solitary, at first terminal but soon overtopped by lateral branchlets, sessile. Bracts 4–6, subsessile, petiole 1–1.5 mm long, semi-amplexicaul, 20 × 3 mm, oblong-lanceolate, frequently glandular-puberulous at the base, margin ciliate, persistent and subimbricate, 3(– 5)-nerved. Hypanthium (at anthesis) 3–4 × 2 mm, narrowly campanulate, glabrous, inconspicuously granulose. Calyx tube ca. 0.2 mm long; calyx lobes (at anthesis) 5–7 × 1 mm, membranaceous, narrowly triangular, glabrous on both surfaces, acute at the apex tapering to a trichome 3 mm long, margin with simple trichomes 2.5–3 mm long, tardily caducous in post-anthesis. Petals 15–20 × 8 mm, pink but greenish-yellow at the base, frequently blue-green or yellowish with a blue flush when dry, oblong to obovate-oblong, apex truncate to obtuse-rounded and asymmetrically apiculate, base attenuate, margins sometimes sparsely and obscurely beset with minute oblong glandular trichomes. Stamens 12, dimorphic: large (antesepalous) stamens 6, filaments 6–7 mm long, yellow, anther thecae 3 × 0.7 mm, yellow turning brown following pollination, oblong, rostrum ca. 0.4 mm long, pedoconnective 6–7 mm long, appendage 1.5–2 mm long, spatulate to clavate, yellow; small (antepetalous) stamens 6, filaments 5 mm long, yellow, anther thecae 2.2 × 0.6 mm, oblong, yellow turning brown, rostrum ca. 0.4 mm long, pedoconnective ca. 1.5 mm long, appendage 0.5 mm long, yellow, rounded to obscurely lobed. Ovary 6- locular, 4/5 inferior, style 11 mm long, curved at the apex, glabrous, pinkish, stigma truncate to punctiform. Fruiting hypanthium (including calyx lobes) 15 mm long, globose to urceolate, yellowish-green. Capsule (at maturity) 0.5–0.7 × 0.5–0.6 mm, globose, enveloped by the persistent hypanthium, dehiscing from the base to the apex. Seeds 0.33–0.58 × 0.22–0.51 mm, oblong to reniform, light yellowish-brown, periclinal cell walls of the testa convex and low domed becoming concave (foveolate), the raphal zone about 35% the length of the seed. Chromosome number unknown.

Illustrations:— Figure 60 ; Schwacke (1900: t. 2).

Photographic images:— Figures 5G, H ; 13C, D .

Phenology:—Flowering from August through December, and April; fruiting from August through February.

Distribution and habitat:—Endemic to Minas Gerais where it is known only from Serra do Cipó in campo rupestre, sandy meadows, stream margins, and adjacent to gallery forests at 1200–1300 m elev. Figure 28 .

Conservation status:—This species is known from fewer than 25 collections. All of these come from a small area of the Serra do Cipó, Minas Gerais, outside of the official boundary of Parque Nacional Serra do Cipó. The EOO is 12 km ² and the AOO is 12 km ². Like other species of campo rupestre and adjacent habitats, fire is the major long-term threat to the survival of this species since it does not appear to form large populations at its known localities. We assign this species a classification of Endangered (EN): B2ab(iii).

Discussion:—Among the species of Lavoisiera with 6-merous flowers and a 6-locular ovary, L. senae is unmistakable by virtue of its linear-oblong to ensiform leaf blades that are glabrous except for a pungent terminal trichome 2.5–3 mm long and conspicuous widely spaced spreading smooth trichomes along the margins. It is also unusual in having calyx lobes that are at least twice the length of the hypanthia at anthesis. Although the petals of this species are pink with a greenish-yellow base when fresh, they typically dry blue-green or yellowish with a blue flush. This is probably why the label on the type describes the petals as yellow. We have not seen this kind of petal color change on drying in any other species of Lavoisiera .

162 • Phytotaxa 315 (1) © 2017 Magnolia Press

MARTINS & ALMEDA LAVOISIERA ( MELASTOMATACEAE )

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The only other species that is remotely similar is L. subulata but it has narrowly subulate leaves closely appressed to the stems (vs. spreading), lacks the smooth trichomes on leaf and calyx lobe margins, and has anther thecae that are dark reddish-purple to purple (vs. yellow), and filaments and pedoconnectives that are bright red (vs. yellow).

Additional specimens examined:— MINAS GERAIS: Mpio. Santana do Riacho , Serra do Cipó. Between Kms 111 and 112 along the road from Lagoa Santa to Conceição do Mato Dentro, 19°17'S, 43°34'W, Almeda et al. 8551 ( CAS!, MO!, NY!, UEC!) ; Serra do Cipó , Mpio. Santana do Riacho , Km 130 on the road from Serra do Cipó (formerly Cardeal Mota) to Conceição do Mato Dentro just S of and downslope from the Juquinha memorial statue, 19°15.593'S, 43°33.176'W, Almeda et al. 8904 ( CAS!, MO!, UEC!) ; Mpio. Santana do Riacho , Serra do Cipó , 22 km from the bridge over the Rio Cipó on the road from Serra do Cipó (formerly Cardeal Mota ) to Conceição do Mato Dentro, 19°15’50.3”S, 43°33'3.3”W, Almeda et al. 9186 ( BHCB!, BM!, CAS!, UEC!) ; Mpio. Santana do Riacho , Serra do Cipó , Anderson et al. 36197 ( NY!, US!); Mpio. Santana do Riacho , Serra do Cipó , Badini 3830 ( US!); Mpio. Santana do Riacho , Serra do Cipó, Badini & Mello Barreto 3379 ( R!) ; Mpio. Santana do Riacho , Serra do Cipó , Km 134, Duarte 2178 ( B!, F!, G!, M!, MO!, NY!, RB!, UB!, US-2!); Mpio. Santana do Riacho , Serra do Cipó , Km 131, Palácio, Duarte 2271 ( G!, RB!) ; Mpio. Santana do Riacho , Serra do Cipó , Km 134, Duarte 3090 ( F!, M!, NY!, RB!, US!); Mpio. Santana do Riacho , Serra do Cipó , Hatschbach 29912 ( C!, COL!, MBM!, MICH!, MO!, NY!, S!, US!); Mpio. Santana do Riacho , Serra do Cipó, Km 128, Joly & Semir 2946 ( UEC!) ; Mpio. Santana do Riacho , Serra do Cipó , Macedo 3779 ( MO!, RB!, S!, US-2!); Mpio. Santana do Riacho, Serra do Cipó, Kms 134–135 , J. Maria 117 ( UB!) ; Mpio. Santana do Riacho , Serra do Cipó , Km 131, Mello Barreto 183 ( NY!) ; Mpio. Santana do Riacho , Serra do Cipó , Km 131, Mello Barreto 185 ( BHCB ex BHMH!, F-2!, NY!); Mpio. Santana do Riacho , Serra do Cipó , Km 128, Palácio, Mello Barreto 187 ( F!) ; Mpio. Santana do Riacho , Serra do Cipó, Mello Barreto 1312 ( RB!) ; Mpio. Santana do Riacho , Serra do Cipó , Km 124, Mello Barreto 7044 ( F!, NY!) ; Mpio. Santana do Riacho , Serra do Cipó , Km 118, Mello Barreto 8510 ( F!, NY!) ; Mpio. Santana do Riacho , Serra do Cipó, Rodovia Belo Horizonte-Conceição do Mato Dentro-Córrego duas Pontinhas, Pirani et al . CFSC 12717 ( SPF!, US!); Mpio. Santana do Riacho , Serra do Cipó , Km 117, Semir 8670 ( UEC!) ; Mpio. Santana do Riacho , Serra do Cipó , Km 120, Semir et al. 4409 ( NY!) ; Mpio. Santana do Riacho , Serra do Cipó, Sena s.n. ( RB!) ; Mpio. Santana do Riacho , Serra do Cipó, Sena 1143 ( BHCB!) .

Figures

FIGURE 5. Images of Lavoisiera species. A−C. L. rundeliana (Almeda et al. 9667). D, F. L. sampaioana (unvouchered images). E. L. sampaioana (Almeda et al. 9198). G−H. L. senae (Almeda et al. 9186). I. L. subulata (Almeda et al. 8571). J. L. tetragona (Almeda et al. 7808). K−L. L. vestita (Aranha et al. 164). Image credits: A−C, E, G−J. Frank Almeda; D, F. Ernesto Lemes; K, L. Gustavo Shimizu.

FIGURE 13. SEM images of seeds for representative Lavoisiera species showing lateral symmetrical plane (left) and detail of testa cells and cell wall microrelief (right). A–B. L. rundeliana (Kameyama et al. 11255). C–D. L. senae (Anderson et al. 36197). E–F. L. subulata (Figuereido & Kubitski 83-22). Scale bars: A & C=250 µm; B=60 µm; D=30 µm; E=200 µm; F=50 µm.

FIGURE 28. Distributions of Lavoisiera caryophyllea, L. chamaepitys, L. minima, L. senae, and L. vestita.

FIGURE 60. Lavoisiera senae. A. Habit. B. Abaxial bracteole surface. C. Hypanthium, calyx lobes and bracteole. D. Ovary crosssection. E. Petal with enlarged detail of margin (upper right). F. Ventral view of antesepalous stamen. G. Ventral view of antepetalous stamen. H. Seed. (Based on: A–H, Almeda et al. 8551, CAS, UEC.)