Terra Nostra Garden 2023 dataset of Camellia species, hybrids and their cultivars (Azores, Portugal)

Abstract Background Camellias cultivars collections, comprising an exquisite array of meticulously bred and curated camellia varieties, emerged as indispensable elements within the resplendent 19th century gardens that adorned landscapes across the globe. The heart of Terra Nostra Garden, nestled within the captivating surroundings of the Furnas volcano on S. Miguel Island (Azores, Portugal), started in the year 1782 as an enchanting fishpond garden, strategically positioned in front of the summer house belonging to the esteemed Thomas Hickling, the American vice-consul. Soon this garden was enlarged and embellished with species from several continents. This tradition continued during all the 19th century with the Viscount Duarte Borges da Câmara Medeiros (1848-1872) and his son the Marquis António Borges Medeiros Dias da Câmara e Sousa (1872-1913). In 1933, the 12 hectares property was acquired by the Terra Nostra Society, led by Vasco Bensaude and increased to 12.5 hectares. In 1935, the current Terra Nostra Garden Hotel was inaugurated and, two years later, the Terra Nostra Society reopened the botanical garden attached to the hotel, now called Terra Nostra Garden. Beginning in 1982, the Head Gardener embarked on a transformative journey, dedicating his expertise to the meticulous renovation and expansion of numerous botanical collections nestled within the garden's enchanting landscapes. Amongst the remarkable transformations, the revered camellias collection received special attention, as it underwent a comprehensive rejuvenation process under his skilful guidance. The recent publication of a global digital dataset of Camellia names provides the opportunity to publish the dataset of Camellia species, hybrids and its cultivars currently cultivated at Terra Nostra Garden with their validated names. New information In June 2023, a total of 669 Camellia phenotypes were identified across the 12.5 hectares of Terra Nostra Garden. These phenotypes include 38 species, 178 hybrids and 637 cultivars. Camelliajaponica represents 81.7% of the 459 species cultivars, while C. x williamsii accounts for 32% of 178 hybrid cultivars. The most prevalent genotypes in Camellia hybrids with known parentage are those of C.japonica, C.saluenensis and C.reticulata present respectively in 64.1%, 45.5% and 37.9% of the hybrids. Regarding cultivar registration, 46.9% were registered in the US, followed by 13% from Japan and 10.8% from Portugal. Although the most ancient cultivar registered growing at the garden is Camelliareticulata Lindl. 'Damanao' from 1621, the majority (69.4%) of cultivars in the garden were registered in the 20th century, followed by the 19th century cultivars (20.7%). One cultivar, Camellia 'Patrícia Bensaude Fernandes', was produced and registered specifically by this garden.


Introduction
Camellia gardens are important for their horticultural value ( Kay et al. 2011), cultural significance (Xin et al. 2015, tourism and recreational opportunities (Chen and Sun 2018), conservation and research efforts (Blackmore et al. 2011, Mounce et al. 2017) and environmental benefits (Primack and Miller-Rushing 2009). They are cherished spaces that celebrate the beauty and significance of Camellia species, while contributing to various aspects of human well-being (Waylen 2006) and ecological balance (Donaldson 2009). th th th th Therefore, gardens of exotic plants offer a therapeutic and immersive experience (Hsieh et al. 2021), connecting individuals with nature (Oh et al. 2022), stimulating creativity, providing educational opportunities, promoting physical exercise and recreation and raising awareness about environmental conservation. Gardens of native plants are also highly relevant for educational puposes, as well as for research and native species conservation (Bishop et al. 2016).
In Azorean Islands, there are very important urban gardens with cultural and aesthetic importance (e.g. Jardim António Borges; Jardim Duque da Terceira, Jardim José do Canto, Jardim do Palácio de Sant'Ana, Terra Nostra Garden), but also an urban garden of native plants (Botanical Garden of Faial Island) (Arteaga et al. 2020). These urban gardens provide not only spaces for relaxation and enjoyment, but also play a significant role in preserving the region's botanical heritage, showcasing local and international plant species and contributing to the overall beauty and cultural fabric of the islands (Sousa 2000, Albergaria et al. 2021).
Of particular relevance is the Terra Nostra Garden (Carvalho 2022). Nested inside the caldera of Furnas active stratovolcano, in Furnas Village, São Miguel Island (Azores Archipelago, Portugal) ( Fig. 1), this garden has more than two centuries of history, an impressive landscape architecture and a range of botanical collections that are of global importance. One of the highlights of the garden is undoubtedly the Camellias Collection, which was awarded with the prestigious title of 'Camellia Garden of Excellence' by the International Camellia Society in 2014 (Costa et al. 2023b).
Terra Nostra Garden has seen a significant boost in tourism in the last two decades, with an impressive 268,044 entries in 2022. This influx of visitors has provided ample opportunity for maintenance, recovery and innovation efforts to be carried out within the garden. Today, the continued garden's improvement requires a management approach, based on digital technology, comprehensive information about the various specimens, their locations and the necessary maintenance actions essential for maintaining the beauty and integrity of Terra Nostra Garden (Costa et al. 2023b).
In this comprehensive contribution, our primary objective is to provide a detailed list of all Camellia species, hybrids and cultivars presently cultivated at Terra Nostra Garden, located in São Miguel, Azores, Portugal. This marks the initial step of an ambitious project dedicated to cataloguing the entire flora within the urban gardens of São Miguel Island.

General description
Purpose: In this paper, we present the dataset of Camellia species, hybrids and cultivars currently cultivated at Terra Nostra Garden, along with their internationally accepted names according to the DICR (Wang et al. 2021, Wang 2023. Additionally, we provide a concise description of the collection.  . 2), nestled within the captivating surroundings of the Furnas volcano (Fig. 3).

Design description:
The georeferencing of garden areas was made in UTM coordinates, using official local reference coordinate system (PTRA08). The survey was possible after the installation of a permanent dense network of aesthetic topographic markers.

Sampling description:
The sampling procedure followed the "Plant Species Prospection" Darwin Core approach using direct observations in 20 plots/sections, located within the Terra Nostra Garden. The codes and coordinates of the 20 plots/sections can be consulted in the GBIF event table in Costa et al. (2023a). From an initial list of 774 names, five names corresponded to synonyms; 16 names are not registered in the International Camellia Register; 20 phenotypes once cultivated were found dead; 64 species cultivars remain to localise; therefore, efforts will be made to identify them in the next blooming periods.

Temporal coverage
Notes: Start date of sampling on 10-01-2023 and end date on 28-04-2023.  year Year of the event.
month Month of the event.
day Month of the event.
habitat Description of the habitat in which the Event occurred (Garden).
locationID An identifier for the set of location information (specific to the dataset).
islandGroup Name of the archipelago of the sampling site (Azores).
island Name of the island of the sampling site (São Miguel).
country Name of the country of the sampling site (Portugal).
countryCode The standard code for the country in which the Location occurs (PT).
stateProvince An identifier for every single event and specific to the dataset (Azores).
municipality Municipality of the sampling site (Furnas).
locality Name of the locality (Terra Nostra Garden). institutionID An identifier for the institution having custody of the object(s) or information referred to in the record.
collectionID An identifier for the collection or dataset from which the record was derived.
institutionCode The name in use by the institution having custody of the object(s) or information referred to in the record.
collectionCode An identifier for the collection or dataset from which the record was derived. datasetName The name identifying the dataset from which the record was derived (Inventory of Terra Nostra Garden Plant Taxa). basisOfRecord The specific nature of the data record (Human Observation).
occurrenceID An identifier built as a "Globally Unique IDentifier". identifiedBy Names of people who assigned the Taxon to the subject.

dateIdentified
The date on which the subject was determined as representing the Taxon. scientificName Full scientific name, with authorship and date information, if known. When identification to species level was not possible, then it is the name in the lowest level taxonomic rank that can be determined.
kingdom Scientific name of the kingdom in which the taxon is classified (Plantae).
phylum Scientific name of the phylum in which the taxon is classified (Magnoliophyta).
class Scientific name of the class in which the taxon is classified (Magnoliopsida).
order Scientific name of the order in which the taxon is classified (Ericales).
family Scientific name of the family in which the taxon is classified. (Theaceae).
genus Scientific name of the genus in which the taxon is classified (Camellia). specificEpithet The species epithet of the scientific name.
infraspecificEpithet Name of the lowest or terminal infraspecific epithet of the scientific name. cultivarEpithet The cultivar epithet of the scientific name. taxonRank The taxonomic rank of the most specific name in the scientific name.
scientificNameAuthorship The authorship information related to the scientific name. Table 1.
Camellia species present at Terra Nostra Garden in June 2023. Some species are not represented by the taxon rank species, but either by a variety or a cultivar.
Camellia japonica represents 81.7% of the 459 species cultivars, while C. x williamsii accounts for 32% of 178 hybrid cultivars (Tables 2, 3). The most prevalent genotypes in Camellia hybrids with known parentage are those of C. japonica, C. saluenensis and C. reticulata (Fig. 4) present respectively in 64.1%, 45.5% and 37.9% of the hybrids (Table 4).    Regarding cultivar registration, 46.9% were registered in the US, followed by 13% from Japan and 10.8% from Portugal (Table 5). Although the most ancient cultivar registered growing at the garden is Camellia reticulata Lindl. 'Damanao' from 1621, the majority (69.4%) of cultivars in the garden were registered in the 20 century, followed by the 19 century cultivars (20.7%) ( Table 6). One cultivar, Camellia 'Patrícia Bensaude Fernandes', was produced and registered specifically by this garden. In this study, we listed 669 Camellia phenotypes that are available across the 12.5 hectares of Terra Nostra Garden. These phenotypes include 38 species, 178 hybrids and 637 cultivars. This collection can contribute to the preservation and conservation of worldwide Camellia plant diversity. Many Camellia species and varieties are endangered or threatened in their natural habitats, so maintaining a collection in a protected environment can help prevent their extinction. Moreover, this collection serves as an important educational resource, allowing visitors to learn about different Camellia species, their th th th th th th st Table 5.
Number of cultivars released per country. Table 6.
Number of cultivars released per century.
characteristics and growing requirements. In addition, Camellias are valued for their attractive and vibrant flowers and the Terra Nostra Garden collection is providing a visually appealing and relaxing environment for visitors to enjoy.