Solanaceae

Stevens

2022

American J of Botany

The inflorescences of Solanaceae are unique and complex, which has led to long-standing disputes over floral symmetry mainly due to different interpretations of the cyme-like inflorescence structure. The main disagreements have been over how the phyllomes associated with the flower were arranged relative to the inflorescence axis especially during early flower initiation. Methods: Here we investigated the evolution of inflorescences in Solanaceae by analyzing inflorescence structure in the context of phylogeny using ancestral state reconstruction (ASR) to determine the evolutionary transitions between loosely arranged and tightly clustered inflorescences and between monochasial-like and dichasial-like cymes. We also reconstructed two-and three-dimensional models for 12 solanaceous species that represent both inflorescence and phylogenetic diversity in the family. Results: Our results indicate that the most recent common ancestor of Solanaceae had a loosely arranged and monochasial-like cyme, while tightly clustered inflorescences and dichasial-like cymes were derived. Compared to the known process of scorpioid cyme evolution, Solanaceae achieved their scorpioid cyme-like inflorescences through a previously undescribed way. Along the pedicel, the two flower-preceding prophylls are not in the typical transverse position of dicotyledonous plants; they frequently have axillary buds, and the main inflorescence axis continues in a sympodial fashion. As a result, the plane of symmetry of the flower is 36°from the median, and the inflorescence axis and the two flower-preceding prophylls are symmetrically located along that plane. Conclusions: A better understanding of the morphological evolution of solanaceous inflorescence structure helped clarify the floral symmetry of Solanaceae.

Section: Figurementioning

confidence: 85%

Evolution and development of inflorescences and floral symmetry in Solanaceae

Stevens

2022

American J of Botany

“…Solanaceae is a medium‐sized, cosmopolitan family of mostly shrubs and herbs in the order Solanales, consisting of approximately 99 genera and 2700 species (D’Arcy, 1991; Barboza et al, 2016). Historically, its taxonomy has been based on reproductive characters, from androecium structure to seed traits and fruit type, both at the level of major clades (Olmstead et al, 1999; Hunziker, 2001) as well as at the generic and specific levels (Zhang and Lu, 1999; Zhang et al, 2005).…”

Section: Figurementioning

confidence: 99%

New physaloid fruit‐fossil species from early Eocene South America

Deanna

Wilf

Gandolfo

2020

American J of Botany

PREMISE: Solanaceae is a scientifically and economically important angiosperm family with a minimal fossil record and an intriguing early evolutionary history. Here, we report a newly discovered fossil lantern fruit with a suite of features characteristic of Physalideae within Solanaceae. The fossil comes from the early Eocene Laguna del Hunco site (ca. 52 Ma) in Chubut, Argentina, which previously yielded the only other physaloid fruit fossil, Physalis infinemundi. METHODS: The fruit morphology and calyx venation pattern of the new fossil were compared with P. infinemundi and extant species of Solanaceae. RESULTS: Physalis hunickenii sp. nov. is clearly distinct from P. infinemundi in its fruiting calyx with wider primary veins, longer and thinner lobes, and especially in its venation pattern with high density, transverse tertiary veins; these features support its placement in a new species. In comparison with extant physaloid genera, the calyx venation pattern and other diagnostic traits reinforce placement of the new fossil, like P. infinemundi, within the tribe Physalideae of Solanaceae. CONCLUSIONS: Both species of fossil nightshades from Laguna del Hunco represent crown-group Solanaceae but are older than all prior age estimates of the family. Although at least 20 transoceanic dispersals have been proposed as the driver of range expansion of Solanaceae, the Patagonian fossils push back the diversification of the family to Gondwanan times. Thus, overland dispersal across Gondwana is now a likely scenario for at least some biogeographic patterns, in light of the ancient trans-Antarctic land connections between South America and Australia.

“… Fabiana is endemic to South America, distributed in southern Peru, Bolivia, Chile, and Argentina, with 15 species of shrubs adapted to the high Andean deserts of Puna, Prepuna, Monte, and Patagonia, growing from sea level to 4900 m elevation in sandy, rocky soils of very low fertility, low organic matter and variable salt content ( Barboza and Hunziker 1993 ; Alaria and Peralta 2013 ; Alaria 2015 ). Fabiana species have characteristic morphological adaptations: leaflessness or small leaves, photosynthetic and resinous stems, and flat or cushion growth habits ( Alaria 2015 ), and they play an important ecological role as codominant shrubs in some plant communities.…”

Section: Introductionmentioning

confidence: 99%

Relationships among Calibrachoa, Fabiana and Petunia (Petunieae tribe, Solanaceae) and a new generic placement of Argentinean endemic Petunia patagonica

Alaria¹,

Chau²,

Olmstead³

et al. 2022

Calibrachoa Cerv., Fabiana Ruiz & Pav., and Petunia Juss. form a clade within tribe Petunieae (Solanaceae). Phylogenetic studies of Petunieae, either as part of a family-wide analysis or focusing on the genera Calibrachoa and Petunia, have either left Fabiana unsampled or included only a single species. These studies have found conflicting relationships among the three genera with all three possible topologies obtained. Petunia patagonica (Speg.) Millán, originally described in the genus Nierembergia Ruiz & Pav., is morphologically distinct within Petunia and geographically disjunct from other members of the genus. For the first time, in this study we include multiple species of Fabiana, Calibrachoa, and Petunia, including P. patagonica. Using three chloroplast DNA regions and the nuclear gene GBSSI, or “waxy,” our results provide strong support for a sister group relationship between Calibrachoa and Fabiana and for the placement of P. patagonica within Fabiana. Since there is already a species Fabiana patagonica Speg., we provide the new name Fabiana australis Alaria nom. nov. to replace Petunia patagonica.