Map（Major gardens & Forest Models）

This arboretum contains 250 Japanese tree species arranged in the following order: evergreen broadleaf trees, deciduous broadleaf trees, and conifers. Visitors can learn about various characteristics of Japanese native trees, including their shapes, bark, leaves, flowers, and fruits.

This arboretum contains exotic Cupressaceae species, such as dawn redwood (Metasequoia), coastal redwood (Sequoia), swamp cypress (Taxodium), and Chinese swamp cypress (Glyptostrobus). In 1941, the late Dr. Shigeru Miki, former director of the Gardens, named the Metasequoia genus based on his discovery of tree fossils. Living specimens were subsequently discovered in Sichuan Province (now Hubei Province), China, and the sole species within this genus was termed a "living fossil." Seeds of Metasequoia glyptostroboides germinated in America, and 100 seedlings were sent to Japan in 1950. One of these trees continues to thrive in the Osaka Metropolitan University Botanical Gardens today.

This arboretum comprises ornamental trees with attractive flowers or distinctively shaped leaves from North America or East Asia, including flowering dogwood (Cornus florida), Formosa sweetgum (Liquidambar formosana), American sweetgum (Liquidambar styraciflua), Western catalpa (Catalpa bignonioides), hardy rubber tree (Eucommia ulmoides), tulip tree (Liriodendron tulipifera), Chinese parasol tree (Firmiana simplex), and tree of heaven (Ailanthus altissima).

Outside of the tropics, East Asia possesses the greatest diversity of tree species. Because of East Asia's proximity to the Japanese archipelago, many tree species native to East Asia are taxonomically closely related to trees in Japan. Furthermore, numerous trees have been introduced to Japan since ancient times for cultivation in gardens and other settings, as ornamental plants or for their medicinal properties. Examples of familiar trees in Japan native to East Asia include Chinese arborvitae (Platycladus), orange-flowered sweet olive (Osmanthus), and Chinese quince (Pseudocydonia).

Many taxonomically related plant species grow in both eastern North America and East Asia, despite their separation by the vast Pacific Ocean. For example, Liriodendron species (Magnoliaceae) include the American tulip tree (L. tulipifera), distributed in eastern North America, and the Chinese tulip tree (L. chinense), found in East Asia. Tree families with parallel species distributions in eastern North America and East Asia include Juglandaceae, Magnoliaceae, Sapindaceae, and Hamamelidaceae.

Eurasia is Earth's largest continent. Due to differing soil and climate conditions between western Eurasia and Japan, few tree species native to Eurasia can grow in the Gardens. Among these are trees with familiar names from literature and paintings, such as the Norway spruce, horse chestnut, and European elm.

This collection contains typical Australian plant species, including those in the genera Eucalyptus, Callistemon, and Callitris. Eucalyptus is a large genus of evergreen trees in the Myrtaceae family, mainly native to Australia. Their flowers have inconspicuous petals, with numerous long stamens as their most distinctive feature. The fruit is a hard, capsule-like structure that splits open to release seeds upon maturity. Eucalyptus trees grow rapidly, and some species are known to be the tallest broadleaf trees worldwide. These trees are economically and ecologically important due to their unique characteristics and extensive range of applications, including timber, paper pulp, essential oils, medicinal purposes, and horticulture.

Callistemon (family Myrtaceae) is a genus of evergreen shrubs or small trees commonly known as "bottlebrushes" due to their distinctive brush-like inflorescences. The flowers form dense, cylindrical or conical spikes characterized by long stamens that protrude like bristles. Flower colors are diverse, including red, pink, purple, white, and yellow; bright red flowers are particularly common. The entire genus is endemic to Australia.

Callitris (family Cupressaceae) is a genus of coniferous trees native to the Southern Hemisphere, widely distributed across Australia and New Caledonia.

The cherry blossom is the national flower of Japan. Among the ten wild cherry tree species native to Japan, the Gardens contain seven, including the Japanese mountain cherry (Cerasus jamasakura) and C. kumanoensis. This garden also includes 68 cultivars. Annually, cherry blossoms reach their peak viewing period over approximately 2 months, beginning with the 'Ohkanzakura' cultivar in late February, followed by single-flowered cultivars such as 'Itozakura', double-flowered cultivars such as 'Kanzan' and 'Baigoji Juzukakezakura' from mid-April, and concluding with the late-blooming 'Nara no Yaezakura'. Visitors can also see six cultivars with green cherry blossoms, including 'Shinnishiki'.

The plum tree holds cultural significance in Japan for its beautiful flowers and fruit. It blooms from late winter to early spring (January to March). The flowers, either single or double, appear in various colors including white, pink, and red. Plum tree flowers bloom before leaf expansion, enhancing their visual impact, and emit a fragrant scent. This garden contains approximately 40 plum tree varieties, among which the 'Genpei' cultivar is particularly distinctive, producing separate white and red flowers on each tree, occasionally on the same branch.

This garden contains approximately 260 camellia cultivars, including about 30 varieties of foreign origin. Varieties bred in the Edo period include 'Kingyo Ba Tsubaki', whose leaf shape resembles the tail fin of a goldfish. The flowers of the five-colored 'Goshiki Chiri Tsubaki' variety have a variegated pattern that combines multiple colors such as white, red, and pink, along with ornamental spots or streaks.

Maple trees or shrubs belong to the genus Acer in the family Sapindaceae and are widely distributed in temperate regions of the Northern Hemisphere. Maple leaves exhibit a characteristic palmate shape, with five to seven deep lobes in many species. Although leaf shape varies among maple species, all are aesthetically pleasing. From spring to summer, the leaves are lush and green; in autumn, they transform into vibrant hues of red, yellow, and orange. Maples are particularly renowned for their autumn leaves. This garden contains Japanese maples and various cultivars derived from the native species. The best time to view the autumn leaves is from mid-November to early December.

Magnolia trees are favored by many gardening enthusiasts. Their petals are thick and firm, with diverse flower colors including white, pink, purple, yellow, and cream. During bloom, their petals open wide, presenting an ornate display. Many magnolia species emit a sweet, pleasant scent to attract insect pollinators. In this garden, visitors can enjoy the attractive flowers and charming fragrance of the Kobushi magnolia (Magnolia kobus), willow-leaved magnolia (Magnolia salicifolia), purple magnolia (Magnolia liliiflora), southern magnolia (Magnolia grandiflora), and the cultivar Magnolia × wieseneri.

Palms, evergreen species belonging to the Arecaceae family, are widely distributed in tropical and subtropical regions. Many palms possess a single, straight trunk, often displaying remnants of leaf bases. Palm leaves have two forms: pinnate leaves, which spread symmetrically like feathers, and palmate leaves, which spread out like the palm of a hand. The leaves are exceptionally large, reaching several meters in length in some species. This garden contains species such as the windmill palm (Trachycarpus fortunei), jelly palm (Butia capitata), and Canary Island date palm (Phoenix canariensis).

Bamboos, plants belonging to the subfamily Bambusoideae of the Poaceae family, are widely distributed from temperate to tropical regions worldwide, mainly in Asia. The height of bamboos significantly varies among species, ranging from a few meters in smaller species to over 30 m in larger species. Typically, bamboos have straight, hollow stems divided at nodes, which are light and strong. The stem color can be green, yellow, or black, depending on the species. Our garden mainly collects bamboo of the genus Phyllostachys, as well as several southern bamboos that form clumps.

Dwarf bamboos are also widely distributed, particularly in East Asia. They range in height from several tens of centimeters to a few meters. These plants are often used as ground cover because of their tendency to expand laterally along the ground.

We cultivate flowering shrubs from Japan and overseas for ornamental purposes. These plants enhance gardens, parks, and roadsides, enriching the landscape with their attractive flowers. The flowers vary in color, shape, and size depending on the species; a variety of flowers bloom throughout the seasons. For example, witch hazel blooms in spring, hydrangeas bloom in summer, and camellias bloom in winter.

Summer-blooming hibiscus cultivars produce vibrant flowers in colors such as red, pink, and purple during hot summer months, adding color to gardens and other landscapes. These flowers attractively contrast with the blue summer sky and green leaves.

The rose of Sharon, a heat-tolerant flowering tree, successively produces pink, purple, and white flowers throughout the summer.

Cotton rosemallow flowers are large and showy, measuring 10 to 15 cm in diameter. They exhibit diverse colors, including white, pink, and red. The flowering season extends from July to October. Although individual flowers last only a single day, new blooms successively appear, allowing for prolonged enjoyment.

Crape myrtle, a deciduous tree, produces flowers with distinctive shapes in pink, red, white, and purple from summer to autumn. It is frequently planted in gardens and parks.

Oleander flowers have five petals and exhibit various colors, including red, pink, and white, depending on the variety. The flowering period is long, with blooms successively appearing from early summer until autumn. Oleander grows rapidly, reaching a height of 2 to 4 m and a width of 2 to 3 m. The entire plant is poisonous, with toxins particularly concentrated in the leaves, flowers, and sap.

In arid climates, land plants exhibit special morphological and physiological adaptations that enable survival with minimal rainfall. These plants may possess fleshy leaves or stems for water storage to withstand prolonged periods of drought. Some plants also reduce transpiration, a process in which plants lose water, by developing smaller or more needle-like leaves. For example, Yuccas have sword-shaped leaves and deep roots for growth in dry environments; puya leaves are sword-shaped, hard, with sharp spines, and arranged in a rosette; and agave leaves are thick, hard, sword-shaped, and have sharp spines. These adaptations prevent water loss in arid conditions.

This garden contains desert plants from North and Central America, creating a landscape characteristic of arid climates. Our Agave americana and Puya alpestris plants first successfully flowered decades after transplanting. Yucca australis blooms only once every few years.

Tropical and subtropical plants are usually grown in our greenhouse, which is closed to the public from October to June. These plants are accessible outdoors only during summer. Our collection of tropical and subtropical plants emphasizes species useful in daily life for food, clothing, and architecture. Many plants in this garden are used to produce luxury grocery items such as tea and coffee, as well as cosmetics. Numerous others are intricately linked to human culture and spiritual activities.

Many aquatic plants are in danger of extinction due to habitat loss caused by human activities, land development, and water quality deterioration. Aquatic plants collected from the suburbs of Osaka are preserved here as refugees. Approximately 80 species of aquatic plants, including endangered species, are grown here, along with horticultural lotus, water lily, and iris varieties.

Species at high risk of extinction and those with endangered wild populations require ex situ conservation efforts. These efforts may include cultivation under controlled conditions, with the expectation of future reintroduction into the wild. This garden exhibits rare plants, including species such as Persicaria attenuata subsp. pulchra, Persicaria japonica var. taitoinsularis, Polygonatum cryptanthum, and Tricyrtis perfoliata, which appeared on the Japanese Red List published in May 2018 by the Ministry of the Environment.

Wetlands in Japan are decreasing in area due to various factors such as land reclamation for development, and many wetland plant species face extinction. In this garden, visitors can see wetland plants, including rare species collected for ex situ conservation, such as marsh club moss (Lycopodiella inundata).