Etymology:
Honouring German naturalist and publisher Berthold Carl Seemann
(1825-1871), collector of the type, who trained as a botanical
collector at Kew and left most of his collections at Kew.
Literature: Mueller 1883, Carruthers 1893, de Laubenfels 1978 (as circinalis), Smith 1979 (as rumphii f. seemannii), Hill 1994. Illustrations: Carruthers 1893, Hill 1994. Historical notes: C. seemannii from Fiji was described by German professor of botany Alexander Carl Heinrich Braun from specimens collected by Seemann in Fiji in 1860. This was generally accepted as a distinct taxon until the confused treatment by Schuster (1932). No type was cited. Smith (1979) designated Seeman 572 as the lectotype of C. rumphii forma seemannii, which was based on C. seemannii and therefore must have the same type. The K and BM sheets bear no locality details, but the specimen in G is labelled `Seemann 572, Viti / Fiji Is., 1860' with a printed label of Kew style. Seemann (1868) records this number as being from `Viti Levu and Ovalau'. These are different islands in the Fiji group, and Seemann was apparently recording the distribution as he knew it, rather than the collection site for the specimen. Schuster (1932) made the combination C. circinalis subsp. seemannii. Kanehira (1938) realised the affinities with C. rumphii, and corrected the error he had perceived in Schuster by making the combination C. rumphii forma seemannii. Kanehira was followed by Smith (1979: 90). The validity of treatment of this species as an infrageneric taxon within both C. rumphii and C. circinalis has been discussed elsewhere (Hill 1994c). The name C. neocaledonica Linden (1881), also cited as Greguss or Linden ex Greguss (in reference to Greguss 1968: 42, 176) is a nomen nudum. Linden only listed the name, and Greguss merely asserted that, on anatomical grounds, this was a species distinct from all others that he had studied. He did not furnish a valid description. Distinguishing features: Distinguished by the relatively narrow leaflets with some but interrupted laminar hypodermis, the relatively short, usually spine-free petiole, the triangular megasporophyll apex with a distinct terminal spine and 18-30 distinct lateral spines 2-8 mm long. Adaxial hypodermis is variably continuous or interrupted by the broad, low midrib. Plants from Vanuatu are generally more robust with broader leaflets, possibly due to genetic admixture from C. bougainvilleana to the north. More clearly intermediate forms occur in the Solomon Islands. Distribution and habitat: Widespread in the south-west Pacific, from Tonga west to New Caledonia, south of about 12° S. A species usually found on calcareous beach dune sands or coral limestone formations, but extending to various substrates on continental islands (except New Caledonia, where restricted to coastal sites, possibly as a result of more recent introduction there). The range of this species has been severely reduced on many islands by intensive shifting agriculture practises. Conservation status: 1997 IUCN Red List of Threatened Plants category R. Vernacular: Longolongo (Fiji and Tonga), Roro (Fiji), No-moll (Eromanga island).
Description:
Stems arborescent, to 4(-10) m tall, 10-20 cm diam. at narrowest point. Leaves deep green, semiglossy, 150-200 cm long, flat (not keeled) in section (opposing leaflets inserted at 180° on rachis), with 150-230 leaflets, with white and orange tomentum shedding as leaf expands; rachis usually terminated by paired leaflets. Petiole 28-39 cm long (16-22% of total leaf), petiole glabrous, unarmed (sometimes spinescent for up to 20). Basal leaflets not gradually reducing to spines, 90-150 mm long. Median leaflets simple, strongly discolorous, 180-290 mm long, 8-15 mm wide, inserted at 45-70° to rachis, decurrent for 4-10 mm, narrowed to 4-7 mm at base (to 33-45% of maximum width), 12-21 mm apart on rachis; median leaflets section flat; margins slightly recurved (sometimes undulate); apex acute, not spinescent; midrib flat above, raised below. Cataphylls narrowly triangular, soft, pilose, persistent. Pollen cones fusiform, orange to brown (pale), 35-50 cm long, 12-15 cm diam.; microsporophyll lamina firm, dorsiventrally thickened, 30 mm long, 15 mm wide, fertile zone 25 mm long, sterile apex 5 mm long, level, apical spine rudimentary or absent, sharply upturned, 0-5 mm long. Megasporophylls 25-35 cm long, white-tomentose and yellow-tomentose; ovules 4-8, glabrous; lamina ovate to lanceolate, 50-85 mm long, 20-40 mm wide, regularly dentate, with 20-30 pungent lateral spines 2.5-8 mm long, 1-2 mm wide, apical spine distinct from lateral spines, 10-20 mm long. Seeds flattened-ovoid, 45-60 mm long, 40-50 mm wide; sarcotesta orange-brown, not pruinose to slightly pruinose, 4-5 mm thick; fibrous layer absent; sclerotesta apically crested. Spongy endocarp present.
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