I thought that for a change, I’d write about something in the Garden I had not written about previously. I settled on weird fruit. In the colloquial (familiar) sense a fruit is a juicy and sweet tasting food. From a strictly botanical standpoint, however, a fruit is a closed vessel that encloses developing seeds. There is, of course, considerable overlap, but most people would not recognize as fruits, a dandelion “parachute,” a maple seed “helicopter” or a string bean—they are fruits, nevertheless. Some need convincing that a tomato is a both a fruit and a vegetable (vegetables are an example of a “folk classification,” where, in this case, edibility without sweetness, rather than relatedness, determines inclusion in the group). But I digress. Only flowering plants produce fruits, and UBC Botanical Garden has plenty of these worth talking about in August. There are so many, in fact, that one needn’t delve into the so-called “fruits” of yews, podocarps, plum-yews and ephedras—none of which are true flowering plants, and all of which bear seeds with animal-attracting appendages. Those fruit-like structures are sufficiently fascinating for discussion at a later date.
Some of the most talked about summer fruits in the Garden (besides the edible ones) are those of the magnolias. Although there are several distinctive magnolia fruit types, there are three basic magnolia fruiting structures that visitors should be able to recognise among the species in the Botanical Garden’s collections. Technically, magnolias produce an aggregate fruit: a follicetum, which is an aggregation of follicles. A follicle is a common fruit type, a dry capsule that splits open along its length by a natural suture to release its seeds. Magnolia fruits look the way they do because of the structure of the magnolia flower, and the common feature that makes a magnolia fruit a follicetum is the spiral arrangement of many tiny separate ovaries that sit on a central conical core (a torus). In all cases, once ovules within the ovaries are fertilized, they become seeds. This signals the torus to expand. In some cases, the ovaries fuse together with the expanding torus, and in other cases, they remain on the surface, unfused, or fuse with the torus but pull away from each other as the torus elongates. When ripe, the Magnolia follicetum dries out such that the individual ovaries (now seed-containing follicles) separate. Before the follicles are completely dry, though, the seeds, which are covered in a bright orange, oil-rich, animal-attracting coating, start to push out through the sutures.
The southern magnolia, Magnolia grandiflora (an evergreen species from the American South), produces an upright follicetum that is about the size and shape of a pine cone. The ever-reliable M. grandiflora cultivar ‘Edith Bogue’ is located next to the Arbour in the Contemporary Garden and frequently produces folliceta, but these seldom expand—probably because Vancouver lacks the late summer heat to ripen them. Southern magnolia is often celebrated for the size of its flowers, but those of Magnolia macrophylla (bigleaf magnolia) are larger. A deciduous species from the southeastern US, bigleaf magnolia also produces a cone-like follicetum, and the earliest produced of these sometimes ripen. Because of the fusion of the follicles they can initially they look like extruded plastic. There are several bigleaf magnolias in the Carolinian Forest Garden and even at a distance they are easily-recognized by their enormous powdery-white-backed leaves. Expanding folliceta are readily seen on the specimen facing southeast in the Fraser Grove.
The yulania (lily flowered) magnolias, of which there are scores in the David C. Lam Asian Garden, are mostly very early blooming large trees that produce long, often contorted, club-shaped folliceta 20 to 35 cm long. These generally turn bright pink to red as they ripen. Unfortunately, the ubiquitous eastern grey squirrel (an invasive species) often harvests them before the seeds are ripe enough to attractively burst out of the follicles. Just as in the southern and bigleaf magnolias, each seed-containing ovary develops into a follicle and is represented by a distinctive bulge in the follicetum. Fruit crops are often inconsistent from individual to individual and from year to year—probably due to weather and pollinator issues. This year, however, the Magnolia sargentii closest to the Ting was already laden with early-ripening folliceta in July. A slightly later-ripening group of fruits is present on the Magnolia sprengeri located where Siebold Trail meets Cox Trail.
A third follicetum type is exemplified by the michelia group of magnolias. This group includes many subtropical trees, but a few species are cold-hardy and present in the Asian Garden. In the case of the michelias, the torus elongates and stretches between the individual follicles. These sometimes resemble pearls on a string. Binoculars are required to see the stringy upright folliceta of the lofty Magnolia ernestii (look waaaay up, across the “creek” from Decaisne Trail downstream of Rock Trail—the Thujopsis dolobrata is directly opposite). An easier subject in this group is the shrubby, evergreen, Magnolia laevifolia (several along the entrance boardwalk and Straley Trail). Both this and the later-ripening taller species regularly produce masses of small flowers and then folliceta comprising pale yellow, globose follicles that burnish pink or red with exposure. No magnification is required to see those of the M. laevifolia, nor the previous year’s occasional dried de-seeded remains, as these are all borne mostly at eye level. But please don’t alert any squirrels.
Written by:
Douglas Justice
Associate Director, Horticulture and Collections
UBC Botanical Garden
