Plainly Unique: Schisandra chinensis Sam Schmerler

he plants of the Arnold Arboretum dis- into elongated fruits with numerous bright red, play incredible floral diversity. Magnolia berrylike fruitlets. Winter will reveal exfoliating Tmacrophylla’s huge waxy blooms open bark resembling that of climbing hydrangea. twice, partly closing in between for an over- Evolutionary biologists (including Arboretum night sex change. Helwingia japonica sprouts director Ned Friedman) have discovered that tiny green umbels in the center of otherwise Schisandra and the other Austrobaileyales can unremarkable leaves. Davidia involucrata for- offer insight into many key events in the his- goes petals entirely, but shelters its reproductive tory of flowering plants. Aspects of Schisandra’s organs with massive white bracts. Even wild vascular system may represent an early step in Viola sororia, flagging down bees with its iconic the development of vessels, the structures that violets, surreptitiously sends out discrete, self- allow most flowering plants to rapidly trans- pollinating flowers underground. port water and ecologically dominate hot and With all this bizarre and beautiful reproduc- dry habitats. Schisandra also retains a relatively tion going on, most of us overlook the most simple anatomy during its haploid stage, with evolutionarily distinctive flowering plant in only four nuclei and one developmental module the collection: Schisandra chinensis. An unas- in each female gametophyte (almost all flower- ing plants have eight nuclei and two modules). suming woody vine, it represents a unique and The endosperm of Schisandra seeds conse- ancient lineage that parted ways with most other quently contains only one complement of genes flowering plants at least as far back as the early from each of its parents, while most flowering Cretaceous, before even “living fossils” like plants acquire an additional copy of their moms’ Magnolia. This ancient group, the Austrobai- genes. Schisandra likely shares these character- leyales, is now recognized as the third-oldest istics with the extinct ancestors of all flowering remaining branch on the phylogenetic tree of plants, a living link to the distant past. flowering plants, diverging after only Amborella But while it retains many archaic anatomi- (a strange New Caledonian shrub) and the Nym- cal features that are long lost in most flower- phaeales (a group of herbaceous aquatics that ing plants, Schisandra has evolved a unique and includes water lilies). This means that all the medically promising biochemistry. Traditional other flowering plants in our collection—from Chinese herbalism prescribes S. chinensis for creeping crowberries to towering tuliptrees—are a whole host of ailments and as a general tonic more genetically similar to each other than any and adaptogen. Recent science has isolated sev- of them are to Schisandra. eral new types of lignans (a class of polyphenols) We can’t grow the other Austrobaileyales here, from the fruits; these have anti-oxidant and since they hail from warmer forests in North anti-inflammatory properties. Schisandra lig- America, Asia, and Oceania, but Schisandra nans have been shown to protect brain cells from chinensis, from temperate northeastern Asia glutamate and liver cells from a variety of toxins; (China, Korea, northern Japan, eastern Russia), they may also inhibit platelet aggregation, tumor can reliably survive Boston winters. This dioe- proliferation, and possibly even HIV replication. cious vine doesn’t appear particularly primitive. As chemists in the food and medical industries Visually, it doesn’t stand out much at all. Our increasingly explore these lignans, it’s likely that two specimens (343-97-B, a male plant from demand for S. chinensis as a pharmaceutical pre- Changbaishan, China, and 409-97-B, a female cursor and “functional food” will increase. from Chiaksan, South Korea) twine unobtru- Even though Schisandra may not dazzle, this sively up his-and-hers trellises in the Levintritt vine’s exciting chemistry and singular evolu- Shrub and Vine Garden and tend to blend in with tionary history prove it truly stands alone. Next their neighbors. Their simple, medium-green time you visit the Arboretum be sure to check leaves are perfectly innocuous, eventually turn- out Schisandra chinensis—it tends to reward ing a bland butter yellow. In late spring, small, closer inspection. white, sweet-smelling flowers droop on thin pedicels in a passable impersonation of nearby Sam Schmerler recently completed his appointment Actinidia (kiwi). The female’s flowers develop as a Curatorial Fellow at the Arnold Arboretum.