A total of 60 ornamental plant species (including six varieties and one subspecies) belonging to 37 families and 48 genera associated with Buddhist figures were identified from China (Table 1). Among the 60 plants, 25 were tree species (41.67%, 10 evergreen and 15 deciduous), 13 shrubs (21.67%, nine evergreen and four deciduous), 13 herbs (21.67%), and nine vines (15.00%). Thirty nine species (65.00%) were native to China, whereas 21 (35.00%) were introduced from other countries. Among the identified species, 43 species (71.67%) were associated with Shakyamuni Buddha, 13 (21.67%) with Bodhisattva, and four (6.67%) with Arhat. It can be concluded that Shakyamuni Buddha, who can guide human moral behavior and deter various evils [2], is the most popular Buddhist figure in China.

Table 1 Characteristics of ornamental plants associated with Buddhist figures in ChinaOrnamental plants associated with BuddhaOrnamental plants associated with Buddha’s birth, enlightenment, and nirvana

Buddha was believed to be born under a Saraca asoca tree, regarded as the original Asoka tree [3] with drooping tender leaves that look like Buddhist kasaya. Asoka and its expanded species S. dives, originated from tropical Asia and grew in S China, but cannot perform well in C and N China because of different climatic conditions. In these regions, the local species Sapindus saponaria has been planted as an alternative to the original Asoka tree. For instance, a 250-year-old S. saponaria tree was cultivated in the Guanyin Temple, Xuchang (Henan Province). The Chinese name for Sapindus, “Wu huan zi”, means have children, which is equivalent to birth, like the Asoka tree. Like the Asoka tree, S. saponaria has pinnately compound leaves with similar leaflets. Additionally, the seeds of S. saponaria are regarded as Bodhi beads “Gui jian chou” [8].

The original Bodhi tree Ficus religiosa, under which the Buddha is believed to have meditated and attained enlightenment, has heart-shaped leaves with long drip tips (Fig. 2A), symbolizing magnanimity, enlightenment, and wisdom [9]. While the species can be planted in southern tropical and subtropical regions to commemorate Buddha and his enlightenment, it cannot grow well in temperate regions [5] and is substituted by climatically suitable local tree species with heart-shaped (or inverted heart-shaped) leaves (Table 1). For instance, F. religiosa was substituted by Syringa sp. (Fig. 2B) in N China, by Celtis bungeana (gold-yellow leaves in autumn, Fig. 2G) in N and E China, by Tilia sp. (Fig. 2E) and Catalpa bungei (Fig. 2F) in N, E, and C China, by Ficus virens (Fig. 2D) in SW China, and by Ginkgo biloba (golden leaves in autumn, Fig. 2C) in C, E, N, NW, and SW of China. These substitute species have been planted as ornamental trees in temples, urban green spaces, courtyards, and indoors as bonsai in China [10,11,12,13].

Fig. 2

The original Bodhi tree and its substitutes. A Ficus religiosa; B Syringa oblata; C Ginkgo biloba; D F. virens; E Tilia sp.; F Catalpa bungei; and G: Celtis bungeana

The most common alternative species used to replace the Bodhi tree was Ginkgo biloba (Fig. 2, OF = 74.23%), the Chinese Bodhi tree [14]. This substitution of the species dates back to at least 1400 years ago when a ginkgo tree was planted by Shimin Li, the second emperor of the Tang Dynasty, in Guanyin Temple, Xi'an, China. Similarly, in NW China, the substitute species S. reticulata for the Bodhi tree traced back to 1379 when the Taer Temple was built around a S. reticulata tree at Xining, Qinghai Province, China.

It is believed that Buddha attained nirvana under a Shorea robusta tree, which is native to the tropical rainforests of Asia [15] and cannot be grown in temperate areas. In the temperate regions, master Xuanzang brought Aesculus chinensis to Tongchuan City 1300 years ago to substitute S. robusta because Sakyamuni gathered his disciples for the first time under the A. chinensis tree [16]. Subsequently, the species was cultivated in Buddhist temples in N, E, and C China. For example, the Great Ci'en Temple in Xi’an, the Wofo Temple in Beijing, and the Lingyin Temple in Hangzhou, China, harbored more than 1000 years old A. chinensis trees commemorating Buddha. In S China, the Couroupita guianensis replaced the original Sal tree. Its flowers and fruits develop together all year round [17], implying reincarnation after death.

Ornamental plants associated with Buddha’s body

During the spread of Buddhism, nine ornamental plants were adopted to commemorate Buddha's body. For instance, the adoption of Annona squamosal (Fig. 3A) was linked to its fruit resembling Buddha’s head. Similarly, the succulent stem of Larryleachia cactiformis (Fig. 3B) and the swollen stem of Phyllostachys edulis “Heterocycla” (Fig. 3H) resembled the spiral hair of Buddha’s head and face, respectively, and were adopted to commemorate Buddha’s body. Some other species adopted to commemorate Buddha included Bambusa ventricosa (Fig. 3D), Jatropha podagrica (Fig. 3E), and Brachychiton rupestris, as their swollen stems resemble Buddha’s belly. Moreover, the fruit of Sechium edule (Fig. 3C) and Citrus medica “Fingered” (Fig. 3F) fruits looked similar to Buddha’s closed and open hands, respectively, and were adopted during the expansion of Buddhism to commemorate Buddha. In addition, the leaves of Sedum lineare (Fig. 3G) resemble Buddha’s fingernails, and the plant was adopted to worship Buddha. Besides adopting to celebrate Buddha’s body, these plant species were widely used as potted ornamentals and planted across the urban landscape and agricultural parks.

Fig. 3

Ornamental plants associated with Buddha’s body. A Annona squamosa; B Larryleachia cactiformis; C Sechium edule; D Bambusa ventricosa; E Jatropha podagrica; F Citrus medica “Fingered”; G Sedum lineare; and H Phyllostachys edulis “Heterocycla”

Ornamental plants associated with Buddha as lotus throne, bamboo monastery, and Bodhi beads

Buddha is often depicted sitting on a lotus throne while lecturing. The original lotus that Sakyamuni sat was the Nymphaea tetragona (Fig. 4A), which has rosette flowers and heart-shaped leaves, representing the symbol of love. Survey results showed 13 plants with lotus-like flowers or leaves were adopted to honor Buddha. For instance, Nelumbo nucifera, Passiflora caerulea, P. coccinea (Fig. 4B), and Trollius chinensis (Fig. 4C) replaced N. tetragona in N China. Curcuma alismatifolia (Fig. 4D) was substituted in S China and Protea cynaroides (Fig. 4E), Lirianthe delavayi (Fig. 4F), Camellia reticulata (Fig. 4G), Musella lasiocarpa (Fig. 4H), and Manglietia insignis (Fig. 4I) in SW China. The remaining Tropaeolum majus (Fig. 4J), Clematis florida, and succulent Echeveria secunda were adopted as a substitute for N. tetragona and to commemorate Buddha. Especially, the flowers of L. delavayi (Fig. 4F) and M. lasiocarpa (Fig. 4H) have a standing upright part in the middle, demonstrating Sakyamuni sitting on a lotus seat.

Fig. 4

Ornamental plants associated with Buddha as lotus throne. A Nymphaea tetragona; B Passiflora coccinea; C Trollius chinensis; D Curcuma alismatifolia; E Protea cynaroides; F Lirianthe delavayi; G Camellia reticulata “Juban”; H Musella lasiocarpa; I Manglietia insignis; and J Tropaeolum majus

It has been suggested that Buddha’s bamboo monastery was the first Buddhist building, which later became a Buddhist temple. Although the original species used in the first bamboo monastery were unclear, some excellent bamboo plants were introduced around Buddhist temples named after bamboo plants. For example, Jin Zhu Temple in Chongqing was named after the bamboo Phyllostachys sulphurea (locally named “Jin zhu”, which means golden bamboo) with golden stalks. The Fang Zhu Temple in Lushan (Jiangxi Province) was named after the Chimonobambusa quadrangularis, with square stalks, called “Fang zhu” in Chinese, which means square bamboo. The Qiong Zhu Temple in Kunming was named after C. tumidissinoda with swollen nodes and is locally called “Qiong zhu”. Additionally, the Senecio rowleyanus was associated with Buddha because its leaves are comparable to Bodhi beads. Nevertheless, these ornamental plants are widely planted in parks, courtyards, and Buddhist temples, as well as indoors, to pray for blessings [3, 18,19,20,21,22,23].

Ornamental plants associated with Bodhisattva

Thirteen ornamental plants were associated with Bodhisattva, including ten species with Guanyin, one with Maitreya with a swollen trunk, one with Manjushri, and one with Sangharama having a homophonic name.

It is believed that the compassionate Bodhisattva Guanyin (known as the Bestower of Children in China) can save and liberate the victims by using the plant branches dip water in her holy bottle and then sprinkle drops of holy water to the human world [24]. The holy branches representing the compassion and softness in Guanyin’s bottle were generally the branches of Salix babylonica (Fig. 5C), S. matsudana, Tamarix chinensis (Fig. 5D), and the leaves of Reineckea carnea (Fig. 5E). The introduced species Alocasia macrorrhizos (Fig. 5F) was associated with Guanyin because its flowers look similar to Bodhisattva Guanyin. It was also believed that Guanyin preaches in the bamboo forest dominated by Phyllostachys nigra (Fig. 5H). The Zizhu temple in Kaohsiung (Taiwan Province, China) was named after P. nigra (Chinese name “Zi zhu”, which means purple bamboo). Additionally, the Bambusa multiplex var. riviereorum (Fig. 5A), Rhapis excelsa (Fig. 5B), and Dracaena sanderiana (Fig. 5G) were regarded as “Guan yin zhu”, which means Guanyin’s bamboo. The plant species associated with Guanyin have been planted around most Chinese Buddhist temples, as well as in parks, courtyards, and indoors [25, 26]. Particularly, the leaves from these plants are cut and used to decorate indoors [25, 26].

Fig. 5

Ornamental plants associated with Bodhisattva Guanyin. A Bambusa multiplex var. riviereorum; B Rhapis excelsa; C Salix babylonica; D Tamarix chinensis; E Reineckea carnea; F Alocasia macrorrhizos; G Crinum asiaticum var. sinicum; and H Gloriosa superba

Ornamental plants associated with Arhat

The Buddhist Arhat, pronounced “Luo han” in Chinese, means everything will succeed. The plants in the genus Podocarpus are called “Luo han song” in Chinese to honor Arhat because their seeds and seed stalks are morphologically similar to Arhat. Especially, P. macrophyllus and P. forrestii have been widely planted in Buddhist temples, urban green spaces, and courtyards and are also potted indoors to pray for wealth and honor [27]. For instance, two ancient P. macrophyllus trees were planted at the Lushan Temple in Changsha City (Hunan Province) when built about 1750 years ago.

Evolving characters of the ornamental plants associated with Buddhist figures

Buddhist figures are popular and most admired in the daily life of Chinese people. Most of the ornamental plants associated with Buddhist figures were planted to admire both plants and Buddhist figures, and to pray for blessings, success, health, and wealth. Some important horticultural plants, such as Annona squamosal and Sechium edule, were associated with Buddhist figures mainly for promoting their commercial market.

Substitution of original plant species associated with Buddhist figures by native species with similar morphological characteristics is considered the main pattern of change for the original plants. For example, the heart-shaped leaves are considered the most prominent morphological feature of the original Bodhi tree, Ficus religiosa, and all nine local substitute species used to commemorate Buddha have heart-shaped leaves. Apart from the shape cues, the color yellow is also an important cue for the adaptation plants, of which 12 species have golden leaves, five species have yellow flowers, and three species bear yellow fruits. Additionally, plants with significant fragrance may help to be selected as the Buddhist figure associated species, such as Curcuma alismatifolia. Another adaptation is introducing non-native species and naming them based on comparable morphological characteristics to Buddhist figures. For example, Jatropha podagrica with swollen stem was introduced from Central America and named “Buddha’s belly tree”. As for the evolving time, the information on the ancient heritage trees in Buddhist temples provides the approximate ages of the beginning of their succession [28].

Multiple use of ornamental plants associated with Buddhist figures

Among the ornamental plants associated with Buddhist figures, 33 (55.00%) were medicinal. Ginkgo biloba is the most commonly used medicinal plant, and the extract from its leaves is used to treat coronary heart disease, angina pectoris, and hyperlipidemia [29]. The Siraitia grosvenorii with Arhat-like roots has significant therapeutic effects on diseases like bronchitis and hypertension [30]. Some plant species were adopted for economic values. For instance, S. grosvenorii has been considered an important economic plant in Guangxi Province for many years because the extract of the species, mogroside, is 300 times sweeter than sucrose and can be used to make beverages [30]. Fifteen out of 60 species (23.33%), including Annona squamosal, Sechium edule, Passiflora caerulea, Nelumbo nucifera, Musella lasiocarpa, Musa basjoo, and bamboo species, have been planted for fruits and vegetables [19, 31]. Some species (Syringa spp. and Tilia spp.) have been planted and used as sources of perfume and nectar [11, 13]. Additionally, bamboo has been used to make papers, walking sticks, and artwork materials [32]. Utility aspects may influence the choices for certain plant species to be placed in Buddhist temples. For example, the species Camellia reticulata were cultivated in the many temples in central Yunnan 400 years ago due to its oil from seeds can be used as Buddhist lamp oil [22].