Magnolia sprengeri Pamp.

This well known plant is one of the decisively tree-forming species of Section Yulania, making a small to medium tree whose big flowers on naked twigs early in spring can make a spectacular show, frosts permitting. A convoluted taxonomic history (see note above) has helped nobody’s understanding, but for the gardener there are simply white flowered and (more commonly) pink ones (now respectively known as var. sprengeri and var. diva). M. sprengeri and M. campbellii are distinguished from M. dawsoniana and M. sargentiana by their upright rather than horizontal or drooping flowers. M. sprengeri differs from the even larger M. campbellii in its more or less obovate (as opposed to more or less ovate) leaves, and in its tepals usually lacking a claw. The recently described M. wufengensis, said to differ in its 9 red-pink tepals, long petioles and persistent pubescence on the midvein beneath (Ma et al. 2006) is recognized in the Chinese research literature but is usually included within M. sprengeri by Western authors (e.g. Royal Botanic Gardens, Kew 2021).

M. sprengeri was described in 1915 from a poor herbarium specimen (see Taxonomic Note above); Pampanini’s specific epithet honours the German nurseryman Carl Sprenger, who could have had no direct connection with the tree. The species became known in cultivation through Ernest Wilson’s 1901 seed introduction from Hubei (Wilson for Veitch 688), an earlier collection from the same expedition failing to germinate. At first unidentified, then confused with M. denudata (Treseder 1978), three unflowered seedling trees passed from Veitch’s Coombe Wood Nursery on its closure in 1913 to Kew, Bodnant (N Wales) and Caerhays Castle (Cornwall). The Kew and Bodnant trees eventually proved to have white flowers (with a purple-pink streak outside in the Bodnant tree), while the Caerhays individual flowered pink and became the type clone of both var. diva and cultivar ‘Diva’: Otto Stapf of Kew equated them with M. sprengeri, the difficulties with varietal names beginning at that point. Wilson later came to believe that he had mixed two collections (Howard 1980). Pink-flowered var. diva is now far more common in gardens than white-flowered var. sprengeri, although the history of name changes means they are not always labelled in this way.

While the name var. sprengeri refers to any white-flowered clone, most in gardens are derived from the original Wilson introduction. In addition to the colour difference, the Wilson stock has shorter, narrower tepals than the original var. diva introduction (Treseder 1978). Philippe de Spoelberch (pers. comm. 2022) highlights the need to conserve this stock as named clonal cultivar(s) just as has been done with var. diva ‘Diva’ (see below), since its distinctiveness is likely to be lost in future seedling generations and among future introductions of more diverse wild material. No name has yet been proposed, however.

The species is hardy enough to grow well in the British Isles, France and the Low Countries, with specimens recorded as far north as Gothenburg, Sweden, and east at least to Bonn, Germany (Gothenburg Botanical Garden 2021; Bonn University Botanic Garden 2021). It thrives in a moisture-retentive acidic soil, in sunny but sheltered sites. Large specimens are spread widely around Britain, away from the coldest central areas. Most are of var. diva, which is arguably the more attractive variety, and certainly the most often planted: examples include trees at Borde Hill, W Sussex (23 m × 203 cm, 2015) and Trewithen, Cornwall (19 m × 324 cm, 2014). Good specimens of var. sprengeri can be seen at Nymans, W Sussex (14 m × 102 cm, 2016) and Caerhays Castle, Cornwall (13 m × 131 cm, 2016 – The Tree Register 2021).

In North America it suits milder areas, especially with influence from the ocean or the Great Lakes. It probably performs best on the Pacific Coast, from San Francisco (where it grows in the Strybing Arboretum), north to Vancouver, BC.

Var. diva has been an important parent of garden hybrids, var. sprengeri less so, although it has been used at Arboretum Wespelaar, Belgium to produce hybrids including ‘Joli Pompon’ (q.v.).