Viviania linostigma R.Knuth, Pflanzenr., 1912

Ferreira, João Paulo Ramos, Hassemer, Gustavo, Campestrini, Sérgio, Weigend, Maximilian & Trevisan, Rafael, 2016, A revision of the extra-Andean Vivianiaceae, Phytotaxa 246 (1), pp. 23-36 : 33-34

Viviania linostigma R.Knuth, Pflanzenr. 4 (129): 573, 1912. ( Fig. 1 M–R ; 2 A )

≡ Linostigma petiolatum Klotzsch, Linnaea 10: 439, 1836. Type:—“ Brasilia ”, s.d., Sellow 3839 (†B). Viviania petiolata (Klotzsch) Reiche, Nat. Pflanzenfam. 3(4): 14, 1897, hom. illeg. Blocking name: Viviania petiolata Hook. & Arn.

Lectotype (designated here):—“ Brasilia ”, s.d., Sellow s.n. (K000531419! photo). Syntype: K000531418! photo.

Decumbent herbs, with sprawling steams, usually radicant in the lower nodes, internodes 1–5.2 cm. Stems subcylindrical, hirsute. Leaves opposite, petiolate, petiole 0.2–1.3 cm length, pilose. Blades 1–2.7 × 1–2.6 cm, generally as wide as long, ovate to broadly ovate, base truncate, subcordate, less commonly obtuse, margins crenate, dark green adaxially with sparce pubecence between the veins, abaxially albo-tomentose. Flowers tetramerous, arranged mainly in the axils of the upper nodes of the stems in groups of 3 per node, subtended by four leaves. Peduncles (1.5–) 2.5–6.5 cm, filiform, tomentose. Calyx tomentose, campanulate, 5–7 mm, united for 1/2–3/5 of its length, calyx lobes acute, with prominent veins. Petals 4, light pink, obtriangular, apex crenate, 0.7–1.5 × 0.5–0.7 cm. Four glands at the base of insertion of filaments, emarginate, divided up to approx. half of their length, surrounding the ovary. Stamens 8, in two series, the larger ones growing above the glands and the smaller ones growing in the space between the glands. Anthers dorsifixed, dehiscence longitudinal. Ovary 2-locular, hirsute, trichomes concentrated at the apex. Stigma bifid, 4 mm, deepely fissured. Style absent or 0.5–1 mm. Locules uniovulate, placentation axial. Fruit a capsule, hirsute. Seeds brown, glabrous, smooth.

Phenology: Flowering August–December, fruiting November–December.

Distribution and habitat: Southeastern Santa Catarina to extreme northeastern Rio Grande do Sul. It is endemic to Araucaria Forest formations in the “Aparados da Serra Geral”.

Conservation status: Vulnerable (VU—B2a, b[i,ii,iii,v]).

Typification: Klotzsch(1836) mentioned as the type of Linostigma petiolatum the collection Sellow3839 “ Brasilia ” ( Brazil), with no specific indication of locality and herbarium. Knuth (1912) analysed the type collection made by Sellow 3839 and 3939, mentioning that they were deposited in herbarium B. However, Lefor (1975) discovered that the type material deposited in the B herbarium was lost. Nevertheless, analysing the images of materials K000531418 and K000531419 we found that their herbarium specimens are from B, likewise have the same information described in Klotzsch (1836) mentioned above, except lacking the Sellow collector´s number. Besides, those K sheets present labels indicating a donation from B and they are annotated by Klotzsch under the name of L. petiolatum. Moreover, Knuth (1912) examined the K000531419 material and have put another label identifying it as Viviania linostigma . Therefore, we consider both materials deposited in K herbarium as syntypes of V. linostigma .

Observations: In contrast to the synonymization of Viviania linostigma under V. albiflora proposed by Lefor (1975) through his analysis of 170 herbarium materials, we verified through analysis of 215 examined materials that there are some characteristics related to the species description that allow its separation from V. albiflora .

The analysed material of Viviania linostigma ( = Linostigma petiolatum) in the present work, as well as the K collection for this species, always represented long-petiolate leaves, with strongly crenate margins and subcordate to truncate, but also less commonly obtuse base. The reproductive features seen in our materials faithfully follow the generic description given by Klotzsch (1836) for Linostigma : tetramerous flower with eight stamens, four glands that surround the ovary, bicarpelar gynecium with present stylus and bifid stigmas, bilocular ovary, uniovulated per locule.

Although Reiche (1897) and Knuth (1912) placed Linostigma petiolatum in Viviania sect. Linostigma under the name of V. linostigma , which they supposed to include specimens with pentamerous flowers, it was not found in the material seen for the present analysis. Moreover, the description of V. linostigma provided by Knuth (1912) cites that only 4 calyx lobes were found, showing that pentamerous flowers were not seen in Viviania sect. Linostigma as pointed out by those authors.

Even more, Viviania linostigma possess a striking feature in the apex of its petals, found in all records of this taxon. The petals of V. linostigma have crenate apex, without an intramarginal vein ( Fig. 1 P ), what does not occur in V. albiflora . This information contradicts not only the drawing found at the Flora Brasiliensis ( Progel, 1872) for the petals of L. petiolatum, which shows that they possess entire and rotund apex, but also Knuth (1912) who determined V. linostigma has petals with rotund apex based on his interpretation under his herbaria analysis and Klotzsch (1836), Reiche (1897), Progel (1872) works. On the other hand, the petals within Caesarea section are differentiated by having entire, or nearly so, truncate apex with venation ending in a intramarginal vein ( Fig. 1 J ), best represented in the illustration of C. albiflora made by Lefor (1975) and Cambessédes (1829) than the one made by Progel (1872) who also draw a rotund apex for this species.

The fact is that flower characteristics shown in the identification key are sufficient to discern reliably Viviania linostigma from V. albiflora . Thus, we propose that V. linostigma must be treated as a distinct species from V. albiflora . Although we accept the name Linostigma petiolatum as synonym of V. linostigma , this should not be seen as an acceptance of the description made by Reiche (1897) and Knuth (1912) for Viviania sect. Linostigma , since we would be agreeing that the scope of variation of this species includes pentamerous flowers, while V. linostigma only has tetramerous flowers.

We allocated the species within the genus Viviania because Weigend (2007) placed all known genera in tribe Vivianieae as synonyms of Viviania and Palazzesi et al. (2012) corroborated this position through molecular analysis. Besides that, it is necessary to determine the actual position of V. linostigma through molecular phylogenetic analysis involving other members included in Viviania by Weigend (2007) and Palazzesi et al. (2012) before to decide segregate in a different genus.

Viviania linostigma is restricted to the states of Santa Catarina and Rio Grande do Sul, endemic to Araucaria Forest formations of “Aparados da Serra Geral” ( Fig. 4 ). This shows that when Lefor (1975) synonymised V. linostigma under V. albiflora , he concealed the distribution of a restricted endemic species amidst to a common species found in Araucaria Forest formation. This synonymisation of V. linostigma left the species “invisible” in the eyes of conservation actions, putting it at risk of extinction in face of the increasing degradation of its habitat. Moreover, the reestablishment of this name will help us to plan for the conservation and management of Araucaria Forest areas within “Aparados da Serra Geral”, being one more element indicative of threatened biodiversity in southern Brazil.

Material examined: : BRAZIL. RIO GRANDE DO SUL: Bom Jesus: entre Bom Jesus e Rio Pelotas , 23 October 1961, E. Pereira 6422 & Pabst 6249 (B; RB) ; SANTA CATARINA: Bom Jardim da Serra: Serra do Oratório , 1400 m, 21 August 1958, R. Reitz & R.M. Klein 6986 (B; F; HBR; MBM; S) ; São Joaquim: Invernadinha , 17 November 2008, J.M. Silva et al. 7278 ( MBM) ; Urubici: Salto Avencal , alto, 17 October 2004, G.G. Hatschbach et al. 78165 ( MBM) ; Parque Nacional ( PARNA) São Joaquim , 28.09379S, 49.38137W, 1519 m, 8 December 2013, R. Trevisan 1423 ( FLOR) ; Urupema: Cachoeira que congela, 27°55’39”S, 49°51’19”W, 1561 m, 6 November 2011, A.C. Cervi et al. 10148 ( MBM) .

Figures

FIGURE 1. Illustrations of Viviania albiflora and V. linostigma. A–L. Viviania albiflora: A–C. General morphological variation. D–H. Leaf variation. I. Flower. J. Petal. K. Stamens and gynoecium. L. Detail of gynoecium.M–R. V. linostigma: M. Habit. N. Leaf. O. Flower. P. Petal. Q. Stamens and gynoecium. R. Detail of gynoecium. Herbarium specimens: A,D,E,F: M. Poloni et al. s.n. (FLOR 16291); B,G: S. Campestrini et al. 476 (FLOR); C,H: R. Reitz & R.M. Klein 11340 (FLOR); M–R: R. Trevisan 1423 (FLOR). Illustrations by Leandro Lopes de Souza.

FIGURE 2. Species of Viviania that occur in Brazil. A. Floriferous branch of V. linostigma. B. Habit of V. albiflora. C. Flower of V. albiflora. Photos by Rafael Trevisan.

FIGURE 4. Distribution of Viviania linostigma.