Ischaemum

Saramollagrass Ischaemum rugosum, from the International Rice Research Institute.

Belongs within: Andropogoneae.

Ischaemum is a genus of tropical grasses in which spikelets are borne in closely appressed pairs (Gardner 1952).

Characters (from Gardner 1952): Generally perennials; leaf-blade convolute when young, becoming flat with age; ligule usually membranous. Inflorescence of compressed paired, digitate or fascicled, rarely solitary, racemes; rhachis readily disarticulating; internodes flattened or subconcave on inner side, often stout. Spikelets in pairs, both alike, or differing only in sex, or more or less heteromorphous, one pedicelled, the other sessile. Sessile spikelet dorsally compressed, often rather broad, deciduous with adjacent internode of rhachis and pedicel. Florets 1–2, when 2, the lower male and upper usually bisexual. Glumes equal or subequal; lower dorsally flattened or somewhat convex, usually coriaceous below, chartaceous and markedly nerved upwards, rarely concave and more or less chartaceous throughout, more or less two-keeled, with inflexed margins; upper boat-shaped, keeled at least above, sometimes awned. Lemmas 2, rigidly membranous to hyaline; lower muticous, empty or subtending a male floret; upper usually two-flowered and awned from sinus, rarely mucronate or muticous, subtending a bisexual floret. Paleas more or less equalling their lemmas, hyaline. Lodicules 2, cuneate. Stamens 3, sometimes small or rudimentary in the fertile floret. Stigmas linear-oblong, dorsally exserted. Grain oblong or lanceolate in outline, dorsally compressed; embryo reaching to middle of grain. Pedicelled spikelet either like sessile in sex and form, or male, or more or less reduced, sometimes apparently laterally compressed with median keel owing to more or less complete suppression of one side, falling entire from its pedicel.

<==Ischaemum [incl. Hologamium, Meoschium]B78
    |--I. arundinaceum Muell. ex Benth. 1878G52 [=I. australe var. arundinaceumLK14]
    |--I. australe Br. 1810G52 [incl. Andropogon cryptatherusB78]
    |    |--I. a. var. australeB78
    |    `--I. a. var. villosum [incl. Andropogon villiferus]B78
    |--I. barbatumC78
    |--I. ciliare [incl. Andropogon malacophyllus, Spodiopogon obliquivalvis]B78
    |--I. commutatumS03
    |--I. decumbensB78
    |--I. fragileB78
    |--I. indicumS03
    |--I. laxumB78
    |--I. mangaluricum (Hack) Stapf ex Fisher in Gamble 1934 (see below for synonymy)PC72
    |--I. muticum [=Andropogon muticus]B78
    |--I. nilagiricumS03
    |--I. pectinatum [incl. Andropogon falcatus]B78
    |--I. pilosumK72
    |--I. rugosumLK14
    |--I. semisagittatumBB01
    |--I. triticeum [incl. Andropogon triticiformis]B78
    `--I. truncatiglumisB78

Ischaemum mangaluricum (Hack) Stapf ex Fisher in Gamble 1934 [=I. aristatum ssp. imberbe var. mangaluricum; incl. I. aristatum ssp. imberbe var. fallax, I. geniculatum Hochst. in Hohenack. 1847]PC72

*Type species of generic name indicated

References

[BB01] Bauer, R., D. Begerow, A. Nagler & F. Oberwinkler. 2001. The Georgefischeriales: a phylogenetic hypothesis. Mycological Research 105 (4): 416–424.

[B78] Bentham, G. 1878. Flora Australiensis: A description of the plants of the Australian Territory vol. 7. Roxburghiaceae to Filices. L. Reeve & Co.: London.

[C78] Clunie, N. M. U. 1978. The vegetation. In: Womersley, J. S. (ed.) Handbooks of the Flora of Papua New Guinea vol. 1 pp. 1–11. Melbourne University Press: Carlton South (Australia).

[G52] Gardner, C. A. 1952. Flora of Western Australia vol. 1 pt 1. Gramineae. William H. Wyatt: Perth.

[K72] Krishnan, M. 1972. An ecological survey of the larger mammals of peninsular India (continued). Journal of the Bombay Natural History Society 69 (2): 297–351.

[LK14] Lyons, M. N., G. J. Keighery, L. A. Gibson & T. Handasyde. 2014. Flora and vegetation communities of selected islands off the Kimberley coast of Western Australia. Records of the Western Australian Museum Supplement 81: 205–244.

[PC72] Patil, R. B., & R. d’Cruz. 1972. On the abundant occurrence of Ischaemum mangaluricum (Hack) Stapf ex C. E. C. Fischer in Maharashtra State. Journal of the Bombay Natural History Society 69 (2): 449–450.

[S03] Singh, J. N. 2003. Grasses and their hydro-edaphic characteristics in the grassland habitat of Nilgiris Biosphere Reserve, Tamil Nadu. Bulletin of the Botanical Survey of India 45: 143–164.

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