Gordonia
I.H. Burkill’s 1917 monograph on Gordonia (Theaceae) is a comprehensive taxonomic treatment that traces the genus from its American origins through its extensive but poorly understood Asiatic radiation, arguing forcefully against the prevailing tendency to split the genus along biogeographic lines and instead proposing its enlargement through the absorption of the Asiatic species of Haemocharris.
Summary
Burkill opens with a detailed account of the nomenclatural history of Gordonia, from Linnaeus’s initial placement of the American Lobolly Bay in Hypericum (1737) through John Ellis’s establishment of the genus (1770) and the subsequent confusion that attended the discovery of Asiatic species, which were variously misassigned to Camellia, Schima, and other genera. The article then surveys the sequence in which over twenty Asiatic species were detected between 1826 and 1916, spanning Java, the Malay Peninsula, Ceylon, Borneo, the Philippines, Sikkim, Tonkin, and South-West China.
The central taxonomic argument of the paper is a rebuttal of Korthals (1839–42) and Pitard (1902), who had each attempted to sever the Asiatic species from the American on the grounds of their discontinuous distribution. Burkill demonstrates that such a distribution pattern is common throughout the allied genera of the Theeae and Ternstroemieae, attributing it to the group’s demand for moist air rather than to any fundamental morphological divide. He further contends that the Asiatic species of Haemocharris—placed there largely on the authority of Miquel—are not distinguishable from Gordonia except for the presence or absence of a style, a character that is itself variable within Gordonia (as in G. singaporiana), and he recommends the two genera be examined with a view to union.
The article also provides practical botanical information: descriptions of timber properties across multiple species, observations on foliage (including the function of mucilage glands on leaf margins), flowering behaviour (noting gynoecism in G. axillaris), seed germination in G. singaporiana, and the sizes attained by various species in the wild. Burkill describes four new species—G. taipingensis, G. concentricatrix, G. Havilandii, and G. lanceifolia—bringing his total count to 28, or well over 30 if the Haemocharris transfer is effected.
Key Findings
- Burkill describes four new species: G. taipingensis (Perak, Taiping Hill, 3,500 ft), G. concentricatrix (Selangor, lowlands between Dindings and Malacca, a 100-foot tree with concentric ring-marked bark), G. Havilandii (Sarawak, Mt. Serapi, 2,800–3,000 ft), and G. lanceifolia (Borneo, near Kuching) (pp. 147–151, 153, 156).
- G. pubescens (L’Heritier, 1784) is reported extinct in a wild state; it was formerly found on the Altamaha River, Georgia, and is distinguished by its wingless seeds and septifragal capsule (p. 146).
- G. Welborni (Elmer, 1908) attains 50 metres (160 feet) with a straight trunk a metre thick, making it the largest known Gordonia; G. singaporiana reaches 43 metres (120 feet) (p. 141).
- The timber of G. hirtella (identified from Cantley’s 1885 collection) has a black heartwood, sinks in water, and is used for durable house posts in the Malay Peninsula (p. 143).
- G. speciosa (Choisy, 1855) is distinguished by deep crimson flowers nearly 10 cm in diameter and stamens united into five groups; it formerly occurred gregariously above Rambodde, Ceylon, at about 4,000 feet but has become very rare due to clearing (p. 156).
- A specimen of G. singaporiana (Tree No. 1505 V, Singapore Botanic Gardens) was measured at 145 cm circumference at 130 cm from the ground, with an estimated height of about 70 feet, recorded for future re-measurement (p. 142).
Conclusion
Burkill’s definitive position is that Gordonia should be neither split along the Pacific nor reduced by the excision of Asiatic species, but rather enlarged by the inclusion of at least the Asiatic Haemocharris, yielding a genus of well over 30 species. He attributes the genus’s discontinuous distribution to climatic constraints on moisture rather than to any morphological discontinuity, and he identifies the re-examination of Sumatran and Bornean type specimens in Dutch herbaria as the most urgent next step toward a stable classification.
Context
- The article draws on material from the Singapore herbarium, the Calcutta herbarium (Royal Botanic Gardens), and references to Dutch collections at Buitenzorg (Bogor), as well as cultivated specimens at Kew and the Singapore Botanic Gardens.
- The study represents a significant contribution to the taxonomy of Theaceae in the Malay region at a time when the genus was in considerable nomenclatural flux, and it directly engages with the monographic work of Choisy (1855), Szyszylowicz (1893), and Pitard (1902).