“Halesia”的意思、由来-开放百科全书

Halesia, also known as silverbell or snowdrop tree, is a small genus of four or five species of deciduous large shrubs or small trees in the family Styracaceae.

Range

They are native to eastern Asia (southeast China) and eastern North America (southern Ontario, Canada south through Florida and eastern Texas, United States).

Description

They grow to {{convert|5|-|20|m|ft|0|abbr=on}} tall (rarely to {{convert|39|m|ft|0|abbr=on}}), and have alternate, simple ovate leaves 5–16 cm long and 3–8 cm broad. The flowers are pendulous, white or pale pink, produced in open clusters of 2-6 flowers, each flower's being 1–3 cm long. The fruit is a distinctive, oblong dry drupe 2–4 cm long. All species except H. diptera have four narrow longitudinal ribs or wings on fruit; diptera only has two, making it the most distinctive of the group.

Species

Halesia monticola is the largest of the genus, with specimens up to {{convert|39|m|ft|0|abbr=on}} tall known in the Great Smoky Mountains National Park in North Carolina; the second-largest is H. macgregorii, reaching {{convert|24|m|ft|0|abbr=on}} in China. The others rarely exceed {{convert|10|m|ft|0|abbr=on}} tall. H. monticola is considered by some to be a subspecies of H. carolina (aka H. tetraptera).^[3] However, there appears to be a consistent size difference between the two taxa.

Taxonomy

The taxonomy and naming of the American species is confused and extensively disputed. The first dispute is over the exact identity of the specimen first named by Linnaeus as H. carolina; some contend that it is the same as H. parviflora,^[4]^[5]^[6] while others say it is the same as H. tetraptera.^[7]^[8]^[9] The second dispute is over whether H. monticola is sufficiently distinct from the other species to merit specific recognition or not (with its varietal placing depending on the above question, too). Neither question has yet been conclusively answered. The treatment here includes both H. carolina (small) and H. monticola (large).

The genus was named after Stephen Hales by John Ellis, publishing the name in the tenth edition of Linnaeus's Systema Naturae in 1759. The name is conserved as the same name had been used in an obscure earlier publication in 1756 for a different plant.^[5]

Fossil record

One fossil endocarp of †Halesia crassa has been described from a middle Miocene stratum of the Fasterholt area near Silkeborg in Central Jutland, Denmark.^[10]

Cultivation and uses

Silverbells are popular ornamental plants in large gardens, grown for their delicate pendulous flowers in late spring.

References

1. ^{{cite web|title=Halesia carolina L.|url=http://www.theplantlist.org/tpl1.1/record/kew-2838104|website=The Plant List (2013). Version 1.1|accessdate=16 September 2015}}
2. ^{{cite web|title=Halesia tetraptera var. monticola (Rehder) Reveal & Seldin|url=http://www.theplantlist.org/tpl1.1/record/kew-2838137|website=The Plant List (2013). Version 1.1|accessdate=16 September 2015}}
3. ^{{cite web|url=http://plants.usda.gov/java/ClassificationServlet?source=display&classid=HATE3|title=Classification -USDA PLANTS|work=usda.gov}}
4. ^Reveal, J. L., & Seldin, M. J. (1976). On the Identity of Halesia carolina L. (Styracaceae). Taxon 25 (1): 123–140. [https://www.jstor.org/stable/1220420 Abstract]
5. ^¹Germplasm Resources Information Network: Halesia
6. ^USDA Plants Profile: Halesia
7. ^Fritsch, P. W. & Lucas, S. D. (2000). Clinal Variation in the Halesia carolina Complex (Styracaceae). Systematic Botany 25 (2): 197–210. [https://www.jstor.org/stable/2666639 Abstract]
8. ^Florida Institute for Systematic Botany: Halesia carolina
9. ^{{Silvics |volume=2 |genus=Halesia |species=carolina |first=Earl R. |last=Sluder}}
10. ^Angiosperm Fruits and Seeds from the Middle Miocene of Jutland (Denmark) by Else Marie Friis, The Royal Danish Academy of Sciences and Letters 24:3, 1985