Lomagramma
Content
Distribution
Asia-Tropical: Assam (Assam present); Thailand (Thailand present), New Hebrides present, S. China present, Solomon present, Tahiti present, eastern Lesser Sunda Is absent, tropical America present
Assam to S. China and Thailand; throughout Malesia except the eastern Lesser Sunda Is.; Solomon and New Hebrides to Tahiti; about 18 spp. (one species in tropical America has been included by Ching, but its status is doubtful,; see p. 278,289).
Taxonomy
John Smith based the genus on the peculiar condition of the fertile pinnae of L. pteroides, which have the sporangia confined to a marginal band with a narrow sterile area between this and the midrib, at least near the base of a pinna. In 1845 Fee based the genus Cheilolepton on L. lomarioides (of which he published a good figure) but did not refer to L. pteroides, presumably because he thought it not to be acrostichoid, though J. Smith had noted its possible identity with L. lomarioides (which he had not seen). Moore also, in his scheme of Classification (1857) placed Lomagramma (limited to L. pteroides) in a group of genera quite distinct from Cheilolepton, which latter he united with Neurocallis (a near ally of Acrostichum s.str.) because of similarity of venation. Hooker (1864) stated that L. pteroides was only an abnormal form of L. lomarioides, and regarded specimens from Samoa (L. cordipinna Holttum) as belonging to the same species. He placed L. lomarioides near Acrostichum s.str. and Neurocallis on account of their common characters of acrostichoid fertile pinnae and reticulate venation. Kuhn (1869) placed Lomagramma as a section of Polybotrya. In his last work Beddome (1892) recognized Lomagramma once more as a distinct genus, and described a new species (L. perakensis); but Diels (1899) relegated it again to a confused mixture of acrostichoid ferns of very diverse affinity in Gymnopteris. Christensen (1904) placed Lomagramma as a section of Leptochilus (another section being Bolbitis) but later recognized it as a distinct genus.
As noted in the introduetory Statement on this group of genera, I regard Lomagramma as closely related to Bolbitis. Lomagramma differs from Bolbitis constantly in Malesia in the following characters: high- climbing rhizome, articulate pinnae, reticulate venation without main veins or included free veinlets and thin-walled spores lacking perispore. In tropical America there is a species of Bolbitis which is very near Lomagramma in venation, B. serratifolia (Kaulf.) Ching. The species originally named Polypodium guianense Aubl. has been placed in Lomagramma by Ching and in Bolbitis by Kramer. It has Lomagramma-like bathyphylls, a high-climbing rhizome and articulated pinnae. In my view it is not closely related to Malesian Lomagramma (see p. 289). There is considerable Variation in the pattern of venation in Bolbitis, and in Malesia also are species which have a reticulate venation lacking free included veinlets, though none lack main lateral veins. Bathyphyll pinnae of Lomagramma have a toothed margin much as some Bolbitis spp. If one has a small detached bathyphyll from a young plant of Lomagramma, the only character by which one can be sure it is not Bolbitis is the jointed pinnae.
Copeland wrote () "at present it does not seem to me quite impossible that our specimens (of Lomagramma) represent a single widely variable species". I am sure that distinct species exist, but admit that in New Guinea I have found their delimitation difficult. More field work is necessary before a better arrangement can be established; information on all stages of development, gained separately in individual localities, is needed. It is possible that hybrids exist, as in Bolbitis.
As noted in the introduetory Statement on this group of genera, I regard Lomagramma as closely related to Bolbitis. Lomagramma differs from Bolbitis constantly in Malesia in the following characters: high- climbing rhizome, articulate pinnae, reticulate venation without main veins or included free veinlets and thin-walled spores lacking perispore. In tropical America there is a species of Bolbitis which is very near Lomagramma in venation, B. serratifolia (Kaulf.) Ching. The species originally named Polypodium guianense Aubl. has been placed in Lomagramma by Ching and in Bolbitis by Kramer. It has Lomagramma-like bathyphylls, a high-climbing rhizome and articulated pinnae. In my view it is not closely related to Malesian Lomagramma (see p. 289). There is considerable Variation in the pattern of venation in Bolbitis, and in Malesia also are species which have a reticulate venation lacking free included veinlets, though none lack main lateral veins. Bathyphyll pinnae of Lomagramma have a toothed margin much as some Bolbitis spp. If one has a small detached bathyphyll from a young plant of Lomagramma, the only character by which one can be sure it is not Bolbitis is the jointed pinnae.
Copeland wrote () "at present it does not seem to me quite impossible that our specimens (of Lomagramma) represent a single widely variable species". I am sure that distinct species exist, but admit that in New Guinea I have found their delimitation difficult. More field work is necessary before a better arrangement can be established; information on all stages of development, gained separately in individual localities, is needed. It is possible that hybrids exist, as in Bolbitis.
Cytology
The only observations are by Roy and Manton on root-tips of plants of L. sinuata and L. melanolepis sent by me from New Guinea and cultivated at Kew; both cases showed 2n = 82.
Citation
J. Sm. 1954 – In: Rev. Fl. Mal.: 477
v.A.v.R. 1908: Handb.: 746
Bedd. 1892: Handb. Ferns Br. India: 105
Baker 1868: Syn. Fil.: 423
Copel. 1960: Fern Fl. Philip: 273-275
Kaulf. p.p. Bl. 1905: Ind. Fil.: xxvi
Copel. 1929 – In: Univ. Cal. Publ. Bot.: 76
J. Sm. 1842 – In: Hook., Gen. Fil.: t. 98
v.A.v.R. 1917: Handb.: 436
Holttum 1937: pp. 190-221. – In: Gard. Bull. S. S.
Holttum 1966: pp. 221-223. – In: Blumea
C. Chr. 1904 – In: Bot. Tidsskr.: 283
C. Chr. 1913: Ind. Fil.: 49 (p.p.), 118