The World of Magnolias

Extrait :

MAGNOLIA SUBGENUS YULANIA

SPECIES OF MAGNOLIA

Magnolia kobus DC.

[Buergeria obovata Siebold & Zuccarini, Magnolia borealis (Sargent) Kudo, M. glahca var. a Thunberg, M. kobus var. borealis Sargent, M. praecocissima Koidz., M. praecocissima var. borealis (Sargent) Koidz., A4. thurberi Parsons ex W. Robinson, M. tomentosa Thunberg, Yulania kobus (DC.) Spach.] Regni Vegetabilis Systema Naturale 1:456. 1817. Type specirnen: not designated. Plates 41-42.

Plants of Magnolia kobus are deciduous trees or srhrubs to 80 ft. (24 m) tall with rough, brownish or silvery gray bark. Twigs are yellow-green becoming brown and pubescent. The terminal buds are covered with yellowish or silvery hairs. Leaves are obovate to oblanceolate, 4-8 in. (10-20 cm) long, 2-4 in. (5-10 cm) wide, dark green and glabrous above, and pale green beneath. The leaf apex is abruptly acuminate; the base is attenuate to cuneate. Petioles are about 1 in. (2.5 cm) long, yellow-green and pubescent. The white flowers are fragrant, with 9-12 tepals. The inner 6-9 petaloid tepals are about 2-3 in. (5-7.6 cm) long. The 3 outer sepaloid tepals are about 1 in. (2.5 cm) long and white to greenish. Stamens are about 0.5 in. (1.3 cm) long, usually purple or rose-colored at the base. The pedicel is about 0.5 in. (1.3 cm) long and more or less pubescent. The follicetum is cylindric in shape or distorted, 2-5 in., (5-12.7 cm) long, and reddish brown. The outer seed coat is red. Chromosome number: 2n = 38.

Magnolia kobus is native to forests and thickets of Japan and is also found on Quelpaert Island, South Korea. The wood of M. kobus is used by the japanese for utensils, engravings, matches, and fuel. This species was first described by de Candolle in 1817. His description was based on several earlier accounts, including a figure by E. Kaernpfer (1712), a description by R. A. Salisbury (1806) of M. gracilis (now considered a synonym for M. liliiflora), and his own specimens.

de Candolle gave this species the epithet kobus because this was given by Kaempfer as the Japanese vernacular narne. The correct vernacular name, however, is Kobushi. Ueda (1986b) has attempted to show that de Candolle's narne M. kobus is invalid by virtue of his inclusion of a reference to M. gracilis (M. liliiflora). But considering the nature of this inclusion, and the inclusion of Kaempfer's plate, it is my opinion that Ueda does not present a suffïciently strong case to warrant changing the long-standing epithet of this species.

In 1908 Sargent described Magnolia kobus var. borealis, a more northerly form of the species, reputedly more vigorous and attaining a greater size than its southern counterpart. johnstone (1955; see "Magnolia Books," chapter references) was the first to question the distinction of this variety, followed by Spongberg (1976) and Gardiner (1989 ; see "Magnolia Books" chapter references). The characters defining the varieties are not consistent, and single plants showing characters of both typical M. kobus and M. kobus var. borealis are not uncommon. Therefore, recognition of a separate botanical variety does not appear justified. Variety borealis is included here within typical M. kobus. It may be important in the horticultural trade to differentiate between typical M. kobus var. kobus and the larger, more vigorous forms previously known as M. k@bus var. borealis. In this case the use of the cultivar narne 'Borealis' is suggested to differentiate.

Magnolia stellata and M. x loebneri are here recognized as M. kobus var. stellata and M. kobus var. loebneri, respectively. A discussion of the evidence leading to this decision is presented in the introduction to this section.

Magnolia kobus is closely related and similar in appearance to M. salicifolia, yet differs in having pubescent buds and pedicels, and in having leaves which are broadest in shape abave the middle. It differs from its variety stellata in having a larger, treelike habit flowers with fewer tepals (usually 9, the outer 3 sepaloid), and larger leaves.

This species was collected, together with var. stellata ' by Dr. George Rogers Hall during his trip to Japan about 1861. Hall then gave plants of Magnolia kobus to Parsons Brothers Nursery of Long Island, New York, in 1862. Parsons named it M. thurberi and distributed it under that name until it was realized that it was actually M. kobus. It was probably introduced into England about 1879 by Charles Maries, a collector for Veitch Nursery.

Magnolia kobus is adaptable to many situations and is also quite cold hardy. Seed germinates readily, but seedlings will require a variable ten to thirty years to flower. Plants propagated from grafts or cuttings take approximately ten years to flower. The species is often used as a hardy, vigorous rootstock in grafting many species of Magnolia. Flowers March-April; fruits August-September. Zones 4-7(8).

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