The cactus and succulent house at Amagasaki Botanic Garden is a virtual gene bank of rare and endangered plants.

AMAGASAKI, Hyogo Pref. -- Once the site of a factory, Kami-Sakabe Nishi Park is a compact botanical garden with an interesting collection of plants, set in the heart of a large industrial city.

Also known as Amagasaki City Botanic Garden, the park was opened to the public in 1984. It has an area of 3.3 hectares, sandwiched between the Inagawa and Mukogawa rivers, and is only 4 meters above sea level and only a couple of kilometers from Osaka Bay. In this part of the country summers are long and hot, and the close proximity of the sea creates a subtropical microclimate. With this in mind it is interesting to see exactly what plants are cultivated in the garden.

Kami-Sakabe Nishi is home to no less than 2,500 species of plants. It has a good collection of Magnolia kobus (kobushi), which blooms in spring with attractive creamy-white flowers with a splash of red or pink at the base of the petals. This deciduous tree is popular in Japan and other countries with a similar climate.

In early June the Juneberry or serviceberry (Amelanchier lamarckii) is laden with delicious purple-black fruit. An excellent tall, fruiting shrub native to eastern Canada, the Juneberry is not particular about soil type as long as it is not waterlogged. Its soft pale-pink flowers are borne in April and May.

The Chinese wing nut (Pterocarya stenoptera) is a tall deciduous tree with large alternate pinnate leaves. In May and June, 18-cm-long green catkins hang from the branches in large numbers. The botanical name originates from the Greek pteron, a wing, and karyon, a nut. Wing nuts belong to the walnut family (Juglandaceae). This species is of Chinese origin and was introduced to Japan at the beginning of the Meiji Era. It is occasionally used as a street tree and the timber is used in furniture.

Two small streams flow through the garden, Kami-Sakabegawa and Koyagawa, and if you are patient you may see a kingfisher (kawasemi, Alcedo atthis) near one of them. More easy to spot is the black kite (tobi, Milvus migrans), a fairly large bird of prey with a wingspan of 150 cm, a common hunter along Japan's rivers and coasts.

A newly planted section at the back of the garden offers several kinds of bamboo. The black bamboo, Phyllostachys nigra, is a Chinese bamboo long cultivated in Japan. Its stems are indeed black, 2-3 meters high and 2-3 cm thick. New stems take a few years before they turn completely black, though.

The golden bamboo (kin-mei moso, Phyllostachys edulis nabeshimana), a variety of the familiar moso bamboo, has stems that are green and golden in color. Moso (P. edulis) is a Chinese bamboo introduced to Japan during the Edo Period (1603-1868) which is grown widely both for timber and food. It is interesting to note that though Japan was in theory closed to the outside world during the Edo Period, many new plants nonetheless entered from China.

Agave huachucensis

The greenhouse is divided into four sections. The tropical house has a nice papaya tree (Carica papaya), which blooms in June and July.

An interesting plant in this section of the greenhouse is Spanish moss, also known as "old man's beard" (Tillandsia usneoides). Not a true moss, Spanish moss is an epiphytic plant resembling gray lichen, native to the Americas from southern Virginia to northern Argentina. Its drooping fringes hanging from tree branches are almost a symbol of the Florida Everglades. It rarely flowers, but absorbs nutrients and water through tiny pores on the surface of the plant. It is propagated by wind and by birds, who use it to make their nests. Dried Spanish moss is widely used as a packing material; in the U.S. alone some 5,000 tons are used annually.

Another section of the greenhouse has a good collection of begonias, many displayed in attractive hanging baskets. One that caught my eye was B. boisiana, a native of Indochina: many-branched, 30-50 cm high, with lanceolate leaves 8-10 cm long, glossy green with purple veins on the underside. Its flowers are white and pink.

The most important section of this greenhouse, however, is the cactus and succulent house. Though small in size it is like a gene bank containing many rare and unusual desert plants. Many of the succulents come from Africa and Madagascar and are now strictly protected by international law under the Washington Treaty.

Aloe Ramosissima, unusual among the aloe family for its branching stem.

Aloe ramosissima, native to South Africa, is a branched shrub with an attractive trunk. Euphorbia stenoclada, from Madagascar, has no leaves; instead the stems themselves are green, and on the short spurs attached to the main branches there are solitary spines to discourage herbivores.

Pachypodium lameri and P. geayi are also native to Madagascar. These are succulents with a difference. Pachypodiums can grow several meters tall in their native habitat. They are covered with stout spines and have a tuft of long and narrow leaves on top of the trunk. In P. geayi the leaves are dark green and covered top and bottom with soft gray hair. It is a strange sight.

The well-known baobab (Adansonia procera) is native to sub-Saharan Africa. Baobabs can grow to a height of 20 meters and the massive, swollen trunk can be up to 10 meters in circumference. They are reputed to live for 1,000 years or more. Unlike most trees that grow in size each year, baobabs may actually shrink in response to extended drought.

All parts of the baobab are useful to humans. The leaves are eaten as a vegetable; the acid seeds are rich in vitamin C and the trunk yields fiber. There are 10 species of Adansonia and all are native to the African continent.

A strong point in this garden is the "green center," a round building with a keyaki tree (Zelkova serrata) growing up through the center. Here any member of the public can bring questions about their favorite plants to the professional staff. There is a small selection of quality reference books in Japanese. Throughout the year exhibitions are held in the green center.

A current show features some excellent photographs of alpines on high mountains in China, all taken by Kazuo Mori, an alpine specialist. They are a refreshing sight in this sea-level garden, where no alpine plants grow.