Kuruna Attigala, Kaththriarachchi & L. G. Clark, 2014

Attigala, Lakshmi, Triplett, Jimmy K., Kathriarachchi, Hashendra-Suvini & Clark, Lynn G., 2014, A new genus and a major temperate bamboo lineage of the Arundinarieae (Poaceae: Bambusoideae) from Sri Lanka based on a multi-locus plastid phylogeny, Phytotaxa 174 (1), pp. 187-205 : 199-200

Kuruna Attigala, Kaththriarachchi & L. G. Clark , gen. nov.

TYPE: Arundinaria debilis Thwaites (1864: 375) .

Kuruna debilis (Thwaites) Attigala, Kaththriarachchi & L. G. Clark

Diagnosis:—Differs from Arundinaria s.s. by its pachymorph culm bases with short necks, culm leaves usually abaxially hispid, culm leaf girdles ca. 1 mm wide, culm leaf auricles absent and the palea apex biapiculate to acute. The following characters differentiate Kuruna from other “ Arundinaria ” groups ( Bergbambos , African alpine bamboos, Thamnocalamus and Yushania ): pachymorph culm bases with short necks, unicaespitose clumps, culm leaf girdles present as a band ca. 1 mm wide, usually abaxially hispid culm leaves with non-irritating hairs, persistent foliage leaf sheaths and complete branch sheathing, palea apex biapiculate (sinus shallow) to acute and undivided, and both spatheate empty bracts at the base of the synflorescence and subtending bracts absent.

Description:— Culm bases pachymorph, short necked, two or more tillers per culm base present. Culms woody, erect, shrubby or scandent; midculm internodes usually hollow, terete to flattened or shallowly sulcate above the branches, smooth, wall thickness (ratio of 2 times wall thickness: culm diameter) moderate (ratio 0.31–0.45) to thick (ratio 0.46–0.61), lacuna greater than 1/3 of the diameter of the culm; nodal lines horizontal; supranodal ridge mostly conspicuous. Culm leaves clearly differentiated from the foliage leaves; girdle present as a band at least 1mm wide; sheath usually abaxially hispid with non-irritating hairs, sheath apex usually symmetrically concave, fimbriate, sheath summit extension present; blade usually reflexed, sessile, more or less narrowly triangular. Branching pattern intravaginal. Branch complement derived from one bud per node and born on a promontory; bud prophyll margins unitary, free; two to several compressed proximal internodes at the base of the primary axis; secondary branches subequal to the primary axis, developing from the second or third compressed internodes and above; central primary branch smaller in diameter than the main culm; three or more leaves per leafy branch and leaf branch apex growth indeterminate. Foliage leaves fimbriate, erect, all leaves with a sheath and a blade; sheath usually strongly keeled at least near the summit. Synflorescences paniculate or racemose, with 1–2 orders of branching, open, terminating the leafy branches, both spatheate bracts at the base and subtending bracts absent. Spikelets pedicellate, laterally compressed, consisting of two glumes, usually two to six female-fertile florets per spikelet (in A. densifolia only one); rachilla extension hairy, bearing a rudimentary floret, shorter than or equal to about half the length of a fertile floret; glumes shorter than the spikelet, unawned; lemmas unawned; paleas 2-keeled, the keels winged, apex biapiculate or acute, sulcus well developed for the full length. Lodicules 3, ciliate; stamens 3, filaments free, anther apex lobes rounded, anther connective lower than the apical anther lobes; stigmas 2 or 3, plumose. Fruit a basic caryopsis with a linear hilum as long as the fruit.

Etymology: —The generic name Kuruna is derived from the common name in Sinhalese of the native Sri Lankan Arundinaria group, “KuruUna”. “Kuru” means dwarf, and “Una” means bamboo.

Distribution:—Warm temperate and montane regions (both forests and open grasslands) of Sri Lanka ( Soderstrom & Ellis, 1988).

Following are the new combinations for all the native Arundinaria species in Sri Lanka: