A Revision of Calyptochloa CE Hubb.(Poaceae), with Two New
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This may be the author’s version of a work that was submitted/accepted for publication in the following source: Thompson, John & Simon, Bryan (2012) A revision of Calyptochloa C.E.Hubb. (Poaceae), with two new species and a new subspecies. Austrobaileya, 8(4), pp. 634-652. This file was downloaded from: https://eprints.qut.edu.au/59503/ c Consult author(s) regarding copyright matters This work is covered by copyright. Unless the document is being made available under a Creative Commons Licence, you must assume that re-use is limited to personal use and that permission from the copyright owner must be obtained for all other uses. If the docu- ment is available under a Creative Commons License (or other specified license) then refer to the Licence for details of permitted re-use. It is a condition of access that users recog- nise and abide by the legal requirements associated with these rights. If you believe that this work infringes copyright please provide details by email to [email protected] Notice: Please note that this document may not be the Version of Record (i.e. published version) of the work. Author manuscript versions (as Sub- mitted for peer review or as Accepted for publication after peer review) can be identified by an absence of publisher branding and/or typeset appear- ance. If there is any doubt, please refer to the published source. A revision of Calyptochloa C.E.Hubb. (Poaceae), with two new species and a new subspecies E.J. Thompson & B.K. Simon Summary Thompson, E.J. & Simon, B.K. (2012). A revision of Calyptochloa C.E.Hubb. (Poaceae), with two new species and a new subspecies. Austrobaileya 8(4): 634–652. Two new species of Calyptochloa C.E.Hubb. (Calyptochloa cylindrosperma E.J.Thomps. & B.K.Simon and C. johnsoniana E.J.Thomps. & B.K.Simon) endemic to central Queensland, and a new subspecies of Calyptochloa gracillima C.E.Hubb. (C. gracillima subsp. ipsviciensis E.J.Thomps. & B.K.Simon) endemic to southeast Queensland are described and illustrated. Key Words: Poaceae, Paniceae, panicoid, cleistogamous, Calyptochloa, Calyptochloa cylindrosperma, Calyptochloa gracillima subsp. gracillima, Calyptochloa gracillima subsp. ipsviciensis, Calyptochloa johnsoniana, Cleistochloa, Queensland flora, taxonomy, new species, new subspecies, identification key E.J. Thompson, c/o Queensland Herbarium, Department of Science, Information Technology, Innovation and the Arts, Brisbane Botanic Gardens, Mt Coot-tha Road, Toowong, Queensland 4066, Australia. B.K. Simon, c/o Queensland Herbarium, Department of Science, Information Technology, Innovation and the Arts, Brisbane Botanic Gardens, Mt Coot-tha Road, Toowong, Queensland 4066, Australia. Introduction Calyptochloa C.E.Hubb., an endemic of axillary spikelets may be produced in the Australian genus, is placed in the subfamily absence of terminal inflorescences. Webster Panicoideae Link, tribe Paniceae R.Br. This (1987) stated that the CL spikelets occur tribe is characterised by the spikelets having singly or in pairs but we have not observed a pair of dimorphic florets with the lower paired spikelets in any specimens at BRI, often incomplete, male or sterile, and falling including those cited by Webster (1987), until entire, the upper fertile, and by the relative we examined the type specimen for one of the induration of the glumes and lemmas (Clayton new species described herein (Calyptochloa & Renvoize 1986; Kellogg & Campbell 1987). johnsoniana E.J.Thomps. & B.K.Simon). In Calyptochloa is amphigamous by having two Calyptochloa, the CL spikelets are obligately types of inflorescences, viz. in terminal and self-fertilised and never open. Plants of axillary positions. The terminal inflorescence Calyptochloa retain the CL spikelets for a few (Connor 1979), is a spike-like raceme with months enclosed in the leaf sheaths before chasmogamous (CH) pedicillate spikelets disarticulation at the culm nodes or at the leaf that open at maturity and thereby potentially sheath bases which then fall at maturity with cross-fertilise. Conversely, the axillary subsequent dispersal of the caryopses. inflorescence usually consists of a single Calyptochloa has remained a monotypic sessile cleistogamous (enclosed self-fertilising genus since description with only C. gracillima flowers) (CL) spikelet which is hidden within C.E.Hubb. recognised until now (Hubbard semi-woody to woody leaf sheaths at each of 1933b; Tothill & Hacker 1983). The genus is several nodes along the culm. In the summer characterised by the perennial mat-forming wet season, the axillary spikelets are produced growth habit and the fertile leaf sheaths at nodes with the terminal inflorescence which enclose the CL spikelets. Clifford & above. At other times of the year, these chains Ludlow (1972) differentiated Calyptochloa from other Queensland grass genera in their Accepted for publication 20 August 2012 key using “stems disarticulating at the nodes at maturity” and “prostrate to creeping” habit. Thompson & Simon, Calyptochloa 635 The genus is both clonal (stoloniferous) and CH spikelets (Campbell et al. 1983) include cleistogamous, a rare combination in grasses the following: (Campbell et al. 1983). a) reduced CL inflorescence size, usually one Cleistochloa C.E.Hubb. (Hubbard spikelet compared to a raceme or reduced 1933a), another perennial panicoid genus panicle from Australia and New Guinea, was b) CL lodicules absent listed by Connor (1981) with Calyptochloa c) reduced size of CL anthers usually amongst 13 genera world wide that possess enravelled in reduced styles clandestine axillary CL spikelets and belong d) upper floret with lemma and palea in four different subfamilies of the Poaceae. convolute towards the apex tightly Seven of these genera have amphigamous enclosing the anthers and styles at anthesis inflorescences and dimorphic spikelets of compared to gaping, and which Calyptochloa and Cleistochloa are e) the CL caryopses a little larger than the the only panicoid genera. Dimorphochloa CH caryopses when present. S.T.Blake (Blake 1941; Simon et al. 2010), Campbell et al. (1983) provided a detailed which is also an Australian CL panicoid classification of CL species comprising genus, was correctly omitted from Connor’s four types based on factors that relate to (1981) list taking into account that this genus prevention of the spikelets from opening had not been synonymised with Cleistochloa including leaf sheath, spikelet parts or the soil (Clayton & Renvoize 1986; Webster 1987) conditions. Campbell et al. (1983) classified at the time. Although Dimorphochloa has Calyptochloa and Cleistochloa as type II amphigamous inflorescences it differs from where fertilisation occurs in spikelets hidden these other genera in terms of the CL spikelets in the lowermost sheaths and this type is as follows: similar to the CH spikelets, usually associated with major inflorescence located apically on branchlets below the and spikelet differentiation. Chase (1908) terminal inflorescences, and not hidden in referred to these clandestine CL spikelets at the leaf sheaths at anthesis. Amphicarpum or near the ground as cleistogenes. However, Kunth, another CL panicoid genus from Calyptochloa and Cleistochloa have CL eastern North America, was also omitted spikelets enclosed in the sheaths in upper from Connor’s (1981) list. Amphicarpum has axils at fertilisation and the upper floret has amphigamous inflorescences and dimorphic modifications including revolute lemma and spikelets but differs by the subterranean CL palea, and lodicules are absent, which prevent spikelets (rhizanthogenes) which are borne at the floret from opening. These characteristics the tips of rhizomes. match type 1 of Campbell et al. (1983) , where Connor (1981) reported that the fertilisation takes place within the leaf sheaths clandestine spikelets are a secondary source of the middle to upper part of the stem but the of seed with most of the seed produced in the spikelet may be exserted at maturity. terminal inflorescences. For the Australian genera the reverse is true with most or all of Hubbard (1933a) stated that as for the the caryopses produced in the CL spikelets. American CL grasses, the Australian species Of about 30 specimens of Calyptochloa are found in arid regions or dry places within gracillima possessing terminal inflorescences humid regions. Calyptochloa is distributed inspected at BRI, only one had CH caryopses. from tropical central Queensland with hot No specimens of Cleistochloa at BRI were humid summers and monsoonal wet season observed to have CH caryopses, thereby to warm temperate south-eastern Queensland confirming this same observation made by with warm humid summers (Map 1). Hubbard (1933a). The Australian genera Calyptochloa spp. are found in mostly well with clandestine spikelets share features, shaded habitats in a variety of vegetation indicative of obligate or habitual cleistogamy communities frequently dominated by Acacia (Connor 1979), which when compared to the spp. on gently undulating to steeply sloping 636 Austrobaileya 8(4): 634–652 (2012) terrain with shallow to skeletal soils derived Taxonomy from a variety of geology but often on Calyptochloa C.E.Hubb., Hook. Icon. Pl. 33: landscapes with lateritic profiles. t. 3210 (1933). Type species: C. gracillima In the current paper we provide a taxonomic C.E.Hubb. account of Calyptochloa, trebling the number Decumbent mat forming perennials; rhizomes of species. Some of these additional species absent. Stolons wiry, c. 1 mm thick; mid-culm have been recognised for some