Chionanthus pygmaeus Small

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Credits

Julian Sutton (2022)

Recommended citation
Sutton, J. (2022), 'Chionanthus pygmaeus' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/chionanthus/chionanthus-pygmaeus/). Accessed 2024-05-29.

Common Names

  • Pygmy Fringetree

Glossary

Critically Endangered
IUCN Red List conservation category: ‘facing an extremely high risk of extinction in the wild’.
endemic
(of a plant or an animal) Found in a native state only within a defined region or country.
USDA
United States Department of Agriculture.
androdioecious
With only male or only hermaphrodite flowers on individual plants.
Critically Endangered
IUCN Red List conservation category: ‘facing an extremely high risk of extinction in the wild’.
xeric
(of habitat or site) Arid. (Cf. mesic.)

Credits

Julian Sutton (2022)

Recommended citation
Sutton, J. (2022), 'Chionanthus pygmaeus' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/chionanthus/chionanthus-pygmaeus/). Accessed 2024-05-29.

Deciduous shrub very much resembling C. virginicus, differing in the following ways: usually a shrub to 2 m (rarely 4 m) in height (versus shrub or small tree to 10 m); corolla lobes shorter, about 1 cm long (versus 1.5–3 cm); tips of anthers blunt or acute, but not prolonged (versus tips prolonged); drupe larger, 2–2.5 cm long (versus 1–1.5 cm), purple-brown when ripe. Leaves elliptic, towards the small end of the range seen in C. virginicus, 3–9 cm long. (Small 1924; Hardin 1974; Bender & Stoll 2010; Dirr 2009).

Distribution  United States Lake region of south-central Florida

Habitat Scrub communities on sandy soils.

USDA Hardiness Zone 7-9

RHS Hardiness Rating H4

Conservation status Endangered (EN)

Endemic to a small part of Florida, endangered as a wild plant, and still little known in cultivation, Chionanthus pygmaeus deserves more attention from gardeners as a comparatively dwarf and potentially very floriferous, if less hardy relative of the more familiar C. virginicus.

C. pygmaeus was first described as distinct from C. virginicus by Small (1924), one of a tranche of new Floridian species he named; the specific epithet refers to the plant’s relatively small stature. Unlike some other segregates of C. virginicus such as C. henryae, it has generally been accepted as a distinct species. The range of variation in C. virginicus is such that without careful observation of the flower and fruit characters listed above, identification can prove tricky (Costner 2021). However, its habitat is quite distinct.

Pygmy Fringetree is a component of several types of scrubby vegetation on deep sand-based soils. These are hot, sunny, xeric habitats, and their plant communities are fire-dependent. Its roots are shallow and wide-ranging, allowing quick uptake of rain or dew (Costner 2021). Regeneration after fire seems to be primarily by suckering from the base; seedling recruitment is rarely observed (Bender & Stoll 2010). Habitat loss is a real threat to this species, with land being given over to building, ranching and agriculture – mainly citrus growing. It is listed as Endangered at both Florida State and US Federal levels, with conservation plans in place (Bender & Stoll 2010).

While its reproductive biology has not been thoroughly studied, casual observation suggests that it is probably functionally dioecious, like C. virginicus. Honeybees and bee flies have been seen visiting flowers of wild plants (Bender & Stoll 2010). It seems that in the American Southeast flowers often emerge just before rather than with the new leaves, giving a superficially Hamamelis-like effect (Costner 2021; Nichols Nursery 2022). The larger fruits are another attraction.

Experience in Florida suggests that this is a floriferous and very desirable garden shrub (Costner 2021). More surprisingly, it is now grown much more widely in North American botanic gardens, which have perhaps been encouraged to test its hardiness by the species’ status as an endangered native plant. In the mid-Atlantic region it is grown at Mt Cuba Center, Delaware (Lady Bird Johnson Wildflower Center 2022), the Scott Arboretum, Pennsylvania (Royal Botanic Garden Edinburgh 2022) and the US National Arboretum, Washington, DC (US National Arboretum 2022) – all USDA zone 7. Further north but on the Pacific seaboard it has been grown for some years on the rock garden at the University of British Columbia Botanical Garden, USDA zone 8 (University of British Columbia 2022). Dirr (2009) reports that the species has survived –25°C, and on this basis suggests it might be hardy to zone 6, perhaps even zone 5. C. pygmaeus is available, if rarely, in the North American nursery trade. As a federally endangered species its garden distribution has probably been limited by the requirement for a costly licence to trade it across US state lines. At the time of writing it is offered at least by Nichols Nursery, NC (grafted plants, sold only within the state – Nichols Nursery 2022) and wholesaler Klyn Nurseries, OH (Klyn Nurseries 2022).

Chionanthus pygmaeus is vanishingly rare in European gardens, despite its potential. Two specimens from American cultivation were grown for some years from 2004 in ordinary garden soil at the Sir Harold Hiller Gardens, Hampshire. They stayed compact, flowered beautifully (with the leaves), but died during a wet winter, despite having survived the very cold winters of 2010 (B. Clarke pers. comm. 2022).

Propagation of C. pygmaeus is problematic. Cuttings do not root readily, and seed dormancy appears to be unusually complex, long-lived, and resistant to a range of dormancy-breaking techniques (Eads & Stewart 2010). Grafting is probably the best available option, with C. virginicus a likely rootstock.