Magnolia grandiflora southern magnolia

Magnolia grandiflora flower, leaves, and trunk; Branner Hall. Sairus Patel, 19 Jul 2017

Magnolia grandiflora leaf. From Trees of Stanford and Environs, Ronald Bracewell

Milk-white and luminous, the flowers of Magnolia grandiflora – the most renowned of the evergreen magnolias – open one by one from late spring through summer, in contrast with deciduous relatives such as the saucer magnolia, which bloom all at once on bare branches in late winter. Each broad, bowl-like blossom measures 5 to 10 inches – and occasionally more than a foot – across; hence the name grandiflora. Individual flowers, studded across the deep green crowns, are visible from high above in aerial views. Their scent – sweet, citrusy, rather like lemon pudding – drifts downward on warm evenings, sometimes surprising even those standing directly beneath, since the flowers may be hidden from view. The tepals are thick; it is said that a message gently inscribed upon them will darken with time, becoming legible in brown script hours later; this could be a useful way to pass on a secret – though not disappearing! – message.

The leaves are equally distinctive: 8 to 10 inches long and half as wide, thick, leathery, and a lustrous deep green above, often coated beneath in a warm russet felt – though this indumentum varies widely in extent and color. The species is hexaploid, carrying six sets of chromosomes rather than the usual two, and is notably variable, especially in its leaves; such polyploidy can foster novel traits and may aid adaptability to diverse environments.

Also variable is the tree’s form. Consider the quartet in the courtyard of Branner Hall: the two at the front have grown much wider than tall, so much so that a full quarter of their spread had to be pruned away on the building side. By contrast, the older one on the back left has clearly invested in growing tall while remaining relatively narrow. The youngest, a replacement, was planted in 2021. Roble Hall’s northwest courtyard has several younger examples. Balconies and upper-story windows are ideal points from which to view and enjoy the blossoms’ fragrance.

The bark is a silvery gray, smooth but finely nubbled, often cracking into broad plates with age. With experience, you can identify the tree by bark alone. Given room, its lower limbs may sweep to the ground; in the South, they sometimes root where they touch soil, forming extended colonies. The leathery leaves decompose slowly and are best left as a natural mulch beneath the canopy. Once fallen, they harden, scraping noisily across hardscaping in gusts of wind; you can break them in two with a satisfying snap, like a thick-cut tortilla chip.

The cone-like fruit, an aggregate of follicles, is studded with seeds that mature to a bright orange-red and are pecked at by birds. These striking fruits are decorative in themselves; many students first notice the species by encountering one fallen on a path. When sliced crosswise, they make an organic printing stamp.

The magnolia is the state flower of both Mississippi and Louisiana, though Mississippi is the Magnolia State. In the South, the tree is known as the bull bay, a name recorded since the late 1700s – with “bull” probably referring to its robust form and “bay” to a regional name for evergreen trees with laurel-like foliage.

See southern magnolias in front of the Post Office. Three remain from a group at the east end of Salvatierra Street; several were replaced by fern podocarpus in 2010.

Cultivar ‘Little Gem’ has become increasingly favored in constrained spaces, with its narrow form and more modest stature; its leaves and flowers are smaller, and its bloom season is greatly extended. One grows in the sunken courtyard at the southwest corner of Old Chemistry. Four more examples flank the lawn in front of Encina Hall, planted in 2019 when the area was reconfigured; compare them with the older magnolias along the building’s facade. In the courtyard behind Encina Hall, at its east end, grows a pair of ‘Samuel Sommer’ – upright in form, with cupped leaves felted rusty-brown beneath, and notably large blossoms.

One magnolia, said to have been a gift from Lou Henry Hoover, stood at 570 Alvarado Row, the original site of the Griffin-Drell house before it was relocated for the Munger Graduate Residence in 2006. A screen of cultivar ‘St. Mary’ ran the length of Sequoia Lane, now the Science and Engineering Quad.

Palo Alto’s more than four thousand southern magnolias line older streets. Along University Avenue, their glinting canopies form a stately entry into Palo Alto, beginning just past the San Francisquito Creek bridge and continuing to Middlefield Road; the first few blocks of this stretch were planted around 1930 through the efforts of the Garden Club, while some recent replacements have been ‘Little Gem’. Several large specimens stand in front of City Hall, their trunks still faintly tinted cobalt blue, a remnant of a 2018 public art project. And at Filoli in Woodside, a magnificent specimen to the left of the house has branches that almost touch the ground, forming an enchanting hideout within.

Illustrations: leaf | Detail of venation.