Pterocarya x rehderiana

Position: Full sun to light shade

Flowering period: Late spring

Soil: Moist, well drained

Eventual Height: 20m

Eventual Spread: 20m

Hardiness: 6a, 6b, 7a, 7b, 8a, 8b, 9a

Family: Juglandaceae

Pterocarya x rehderiana, commonly known as Rehder Wingnut, is a vigorous deciduous tree with a rounded, spreading habit. Pterocarya x rehderiana is hybrid between Pterocarya fraxinifolia and Pterocarya stenoptera. Its mid green leaves are compound. Its flowers are light green and appear as pendulous catkins that are up to 40cm long. These are followed by green winged nutlets. These nutlets mature to brown in late summer and remain on the tree during the winter months. Pterocarya x rehderiana may be used as a specimen tree for sunny locations, where space allows.

Pterocarya x rehderiana (28/07/12, Kew Gardens, London)

Pterocarya x rehderiana Flower (28/07/12, Kew Gardens, London)

Pterocarya x rehderiana Leaf (28/07/12, Kew Gardens, London)

Pterocarya x rehderiana Bark (28/07/12, Kew Gardens, London)

Landscape Architecture

Juglans major

Juglans major (15/08/15, Kew Gardens, London)

Position: Full sun

Flowering period: Late spring to early Summer

Soil: Moist, well drained

Eventual Height: 15m

Eventual Spread: 15m

Hardiness: 7a, 7b, 8a, 8b, 9a, 9b

Family: Juglandaceae

Juglans major is a fast growing,  deciduous tree with a broad crown. Its bright green leaves are odd-pinnate, composed of up to 19 leaflets and up to 32cm long. Its leaflets are lanceolate with serrulate margins, hairy when young, up to 10cm long and 4cm across. Its branches are light grey with rufous hairs when young, becoming dark grey to brownish black and glabrous as they mature. Its trunk may achieve a diameter of 1.3m. Its bark is grey/ black and deeply furrowed. The species is monoecious. Male yellow/ green flowers are in the form of drooping catkins which are up to 20cm. Its green female flowers are small and insignificant, are terminal and appear solitary or occasionally in pairs. Its fruit are green/ brown, almost round, up to 3.5cm across when ripe in autumn and contain edible walnuts.

Juglans major Leaf (15/08/15, Kew Gardens, London)

Juglans major, commonly known as the Arizona Walnut, Arizona Black Walnut or Nogal Silvestre, is native to south west North America, predominantly Mexico. In its native habitat it usually grows in dry rocky ravines and stream beds. Juglans major is synonymous with Juglans elaeopyren, Juglans microcarpa var. major and Juglans rupestris.

The etymological root of the binomial name Juglans is from the classical Latin name for Juglans regia. Major is derived from the Latin meaning ‘greater’.

The landscape architect may find Juglans major useful as a large fruiting tree, it may be suitable for a community garden where space allows. It is also suitable as an attractive parkland tree. Care should be taken in locating this tree as its roots, leaves and nut husks secrete a substance, Juglone, into the soil which inhibits the growth of some plants.

Juglans major Bark (15/08/15, Kew Gardens, London)

Ecologically, Juglans major fruit are attractive to some birds and mammals who eat its nuts.

Juglans major  prefers moist, humus rich, deep, well-drained soils. It tolerates most pH of soil. It is especially tolerant of alkaline conditions.

Juglans major requires little maintenance. Necessary pruning should be carried out in late summer to early autumn while the tree is fully dormant. Suckers should be removed as the appear.

Landscape Architecture

Pterocarya stenoptera

Pterocarya stenoptera (15/08/15, Kew Gardens, London)

Position: Full sun

Flowering period: Summer

Soil: Moist, well drained

Eventual Height: 20m

Eventual Spread: 15m

Hardiness: 6a, 6b, 7a, 7b, 8a, 8b, 9a

Family: Juglandaceae

Pterocarya stenoptera Fruit (15/08/15, Kew Gardens, London)

Pterocarya stenoptera is a fast growing deciduous tree with a spreading habit. Its bright green leaves are even pinnate (rarely odd pinnate) and are up to 25cm long and composed of up to 25 leaflets. Its leaflets are elliptic to lanceolate with serrulate margins and are up to 12cm long and 3cm broad. In autumn its leaves turn yellow before they fall. Its trunk can reportedly reach up to 2.5 meters in diameter. Its grey bark has deep fissures which are coloured orange. Its monoecious flowers are pale green, racemose, up to 45cm long when female, 18cm long when male (however some studies have found functional hermaphroditic flowers) and wind pollinated. Its fruit are a nutlet, up to 7mm across with two wings up to 6mm across and ripen in late autumn to early winter.

Pterocarya stenoptera, commonly known as the Chinese Wingnut, is native to eastern Asia. In its native habitat it grows on mountainsides and along river and stream banks.

Pterocarya stenoptera Leaf (15/08/15, Kew Gardens, London)

The etymological root of the binomial name Pterocarya is derived from ancient Greek meaning ‘winged-nut’.  Stenoptera is from the Greek stenos meaning ‘narrow’ and pteron meaning ‘wing’.

The landscape architect may find  Pterocarya stenoptera useful as an unusual specimen tree with attractive hanging fruit suitable for damp soils, particularly on river edges.

Pterocarya stenoptera Bark (15/08/15, Kew Gardens, London)

Ecologically,  Pterocarya stenoptera fruit are attractive to some birds and mammals.

The Royal Horticultural Society have given the cultivar Pterocarya stenoptera ‘Fern Leaf ’ their prestigious Award of Garden Merit in 2012.

Pterocarya stenoptera prefers moist, fertile, well-drained soils. It tolerates most pH of soil.

 Pterocarya stenoptera requires little maintenance. Pruning should be carried out during the summer months to prevent bleeding.

Landscape Architecture