Siphocampylus antonellii Lagom. & D. Santam., 2016

Lagomarsino, Laura P. & Santamaria-Aguilar, Daniel, 2016, Two new species of Siphocampylus (Campanulaceae, Lobelioideae) from the Central Andes, PhytoKeys 58, pp. 105-117 : 107-110

Siphocampylus antonellii Lagom. & D. Santam. sp. nov. Figs 1 , 2

Diagnosis.

Siphocampylus antonellii is similar to Siphocampylus elfriedii , but differs in its smaller, linear-oblanceolate leaves, ventral corolla lobe>1.3 cm long, and pleasant, lemon-like odor emitted from living plants.

Type.

Peru. Cusco: Calca, Lares, Calle entre Amaparaes y Suyo, Arriba de Amaparaes, 12°58'902"S, 077°50'W, 3799 m, 10 December 2012 (fl), L. Lagomarsino, D. Santamaría, J. Wells, F. Farro 400 (holotype: A!; isotypes: GB!, MO!, NY!).

Shrub 1.5 m tall, branching 20 cm above the base, with soft wood; branches 0.2-0.6 cm in diameter, solid and fistulose, light brown to reddish purple in living material, glabrescent or white-tomentose; internodes 0.2-1.0 cm long; latex white. Leaves spirally arranged, distributed evenly along the branches, producing lemon-like odor; petiole 0.1-0.5 cm long, sometimes subsessile, villous, the trichomes whitish, adaxially canaliculate, abaxially rounded to triangular; lamina 3.8-5.2 × 0.3-0.55 cm, linear-oblanceolate, not rugose, appearing glabrous but densely pubescent with diminutive, whitish, stellate to echinoid trichomes; base attenuate to decurrent, sometimes with uneven sides; apex acuminate; margin sinuate, subentire, or diminutively dentate, 11-25 teeth per side, rounded to uncinate, sometimes appearing as a glandular callosity; venation reticulate, with 5-10 pairs of lateral nerves, ascending, impressed or indistinct adaxially, flat abaxially. Flowers solitary, axillary, generally towards the apex of branch; pedicel 3.0-5.0 cm long, straight for almost the entire length, but curved below the hypanthium, cylindrical or flattened, densely pubescent, bibracteolate; calyx lobes 5, 0.7-1.6 × 0.1-0.12 cm, linear-oblanceolate, margins diminutively dentate with 3-5 teeth per side, densely pubescent on both surfaces, straight, the apex acuminate; corolla (2.8-) 3.9-5.1 cm long, tube pink with yellow to light green lines parallel to the lobes, lobes light green-yellow externally, light yellow to cream colored inside, completely pubescent externally, pubescent internally with stellate to echinoid trichomes; tube 2.7-3.5 × 0.4-0.6 cm, constricted at the base and widening distally, straight at anthesis; corolla lobes 5, lanceolate to narrowly triangular, apex acute to acuminate, the two dorsal lobes 1.0-1.6 cm long, the two lateral lobes 1.3-1.5 cm long, the ventral lobe 1.4-1.9 cm long; staminal tube 3.5-4.5 × 0.1 cm, straight, glabrous, cream-colored to light green in living material, exserted between the two dorsal lobes; anther tube 0.5-0.7 × 0.2-0.21 cm, dark gray, glabrous, ventral anthers 0.4-0.6 cm long, penicillate at the apex, the trichomes white or yellowish gold, dorsal anther 0.45-0.6 cm long, glabrous. Fruits not seen.

Distribution and habitat.

Siphocampylus antonellii is endemic to Peru, where it grows on rocky slopes in puna habitat at ~3800 m in elevation. It is only known from the type collection.

Phenology.

Individuals were collected in flower in December; the rest of the phenology of this species remains unknown.

Etymology.

It is an honor to name this attractive species for Dr. Alexandre Antonelli (1978-), a biogeographer and phylogeneticist at the University of Gothenburg. Antonelli has made many important contributions to our understanding of Neotropical biodiversity through space and time, and to the evolution of various taxa, including Lobelioideae . His efforts in the latter brought the second author to the field in Costa Rica in 2005 in search of Campanulaceae , and helped to inspire the first author to study Centropogon , Siphocampylus , and Burmeistera .

Conservation status.

Siphocampylus antonellii is endemic to a narrow stretch of high-elevation grassland (puna) in Calca, Peru, where it is locally abundant. Only a single population of this species is known, from which the type collection was made. Due to its small area of occurrence and the threat of future deforestation in its habitat, we tentatively consider this species to be Vulnerable ( IUCN 2014). Its vulnerable status is further justified by its roadside occurrence, near major construction efforts.

Discussion.

Siphocampylus antonellii is most similar to Siphocampylus elfriedii E. Wimm. (Fig. 3C ) and Siphocampylus parvifolius E. Wimm., which are both also endemic to Peru. These species share a shrubby habit (Fig. 2A ), generally high elevation occurrence ([1050-] 2100-3800 m), bibracteolate pedicels (Figs 1C , 2F ), pink or pinkish-purple corolla tubes with yellow-green lobes (Figs 2F-G , 3C ), glabrous anthers (except at the apex of the ventral anthers) (Figs 1F , 3C ), and turbinate ovaries (Figs 1C , 2F , 3C ). Both Siphocampylus antonellii and Siphocampylus elfriedii produce echinoid trichomes, following Batterman and Lammers 2004. However, Siphocampylus antonellii can be easily distinguished by the differences enumerated in Table 1 and by the agreeable lemon-like smell that it emits.

This new species would be placed near Siphocampylus nobilis E. Wimm. and Siphocampylus rosmarinifolius G. Don in the dichotomous key of genus in Wimmer (1953). In addition to being restricted to Peru, these species share linear leaves, turbinate ovaries, and narrow corolla lobes. However, these two species have glabrous sepals and corolla (vs. pubescent in Siphocampylus antonellii ), ebracteolate, glabrous pedicels (vs. bibracteolate and pubescent), and different corolla colors: reddish orange with yellow lobes in Siphocampylus rosmarinifolius and purple in Siphocampylus nobilis (vs. pink with yellow-green lobes [Fig. 2F ]). Siphocampylus nobilis can be further distinguished from Siphocampylus antonellii by its vining habit (vs. shrubby), long, narrow leaves (6.0-8.0 × 0.2-0.3 vs. 3.8-5.2 × 0.3-0.55 cm), and glabrous branches, leaves, pedicels, and hypanthium (vs. pubescent [Fig. 1 ]). Siphocampylus rosmarinfolius can be further distinguished by its longer leaves (8.0-11.5 cm vs. 3.8-5.2 cm), the rugose, glabrous adaxial leaf surface (vs. not rugose and pubescent), and revolute leaf margins (vs. not revolute).

Molecular phylogenetic analysis places Siphocampylus antonellii in a well-supported clade that includes Siphocampylus actinotrix E. Wimm. (Fig. 3B ), Siphocampylus elfriedii (Fig. 3C ), Siphocampylus vatkeanus Zahlbr., Siphocampylus veteranus E. Wimm. (Fig. 3A, D ), and Siphocampylus rictus Lammers; within this clade, Siphocampylus antonellii is sister to Siphocampylus veteranus ( Lagomarsino et al. 2014). This clade as a whole is composed of generally tall, woody shrubs. The placement of Siphocampylus elfriedii in this clade is not surprising, as it is quite similar to Siphocampylus antonellii (see above). However, it is more difficult to find similarities with the remaining species, which can be easily distinguished from Siphocampylus antonellii by a series of putative adaptations to pollination by bats: long pedicels (7.0-15 cm), wide corolla apertures, and longer corollas (3.2-5.0 cm) that are generally dull in color (either green, cream-colored, white or yellowish, sometimes mottled with reddish pigmentation) (Fig. 3A-B ). Additionally, these species have longer leaves (6.0-13.5 cm vs. 3.8-5.2 cm) and a glabrous or only sparsely pubescent corolla (but with echinoid-stellate pubescence in Siphocampylus actinothrix [Fig. 3B ]). Despite the similarities discussed above, Siphocampylus rosmarinifolius falls outside of the clade that includes Siphocampylus antonellii ( Lagomarsino et al. 2014); Siphocampylus nobilis and Siphocampylus parvifolius have not yet been sampled in a molecular phylogenetic analysis.

Figures

Figure 1. Siphocampylus antonellii. A Flowering branch B Leaf, abaxially, including detail of leaf margin and stellate hairs that cover surface C Staminate-phase flower, including bibracteolate pedicel, with detail of sepal and stellate hairs that cover the outer corolla surface D Longitudinal section of a pistillate-phase flower, showing the insertion of staminal tube to corolla, style and stigma as situated relative to the stamens, and bilocular ovary with axile placentation E Corolla lobe detail F Detail of anther tube, including apical hairs on ventral anthers, and stigma. Drawing by Bobbi Angel from the type.

Figure 2. Siphocampylus antonellii. A Habit and high-elevation grassland (puna) habitat B Flowering branch C Cross-section of stem showing woody habit D Adaxial leaf surface E Abaxial leaf surface F Lateral view of flower in staminate phase G Anterior view of a flower, showing corolla aperture. All photos of the type collection, taken in the field by L. Lagomarsino.

Figure 3. Closest relatives of Siphocampylus antonellii, based on molecular phylogeny of Lagomarsino et al. (2014). A Flower of Siphocampylus veteranus B Flower of Siphocampylus actinothrix C Flower of Siphocampylus elfriedii D Cross-section of main stem of Siphocampylus veteranus, showing a much more robust habit than Siphocampylus antonellii, but similar wood structure. All photos taken in the field by L. Lagomarsino. A, D L. Lagomarsino et al. 388 B L. Lagomarsino et al. 403 C L. Lagomarsino et al. 387.