Calyptochloa gracillima subsp. gracillima

Calyptochloa  gracillima subsp. gracillima

Decumbent stoloniferous perennial. Ascending branches to 25 cm tall, copiously branched with 10–30 nodes. Stolons to c. 1.5 m long. Mid-culm leaf blades 25–40 mm long, 2.5–5 mm wide; adaxial surface with sparse to moderately dense simple hairs 0.3–1.6 mm long and usually some tubercle based hairs to 3 mm long on margin at base; abaxial surface with moderately dense simple hairs 0.2–0.8 mm long. Mature fertile leaf sheaths 10–17 mm long, 1.5–3 mm wide near base with wall 0.3–0.4 mm thick.  Sterile leaf sheaths with tubercle-based bristles c. 0.3 mm long and simple hairs c. 1.3 mm long. Terminal inflorescences on axes 1–3 cm long, 5–8-flowered. Spikelets 3–5  mm long (without awn), 1.3–1.8 mm wide; lateral pedicels 0.4–2 mm long, apical pedicel 2–4.5 mm long. Lower glume triangular to lanceolate, 0.2–1.3 mm long. Upper glume 3–5 mm long; apex truncate. Lower lemma 3–5 mm long. Upper lemma 3–3.5 mm long, awn 2–3 mm long; lodicules 0.2–0.4 mm long; palea 2.5–3 mm long, rarely awned, awn to 2 mm long. Anthers (0.5–1) 1.6–2 mm long. Caryopsis (1.6–1.8) c. 2.3, rarely seen. Axillary inflorescences usually present at 5 (3–10) internodes. Spikelets 4–5.5 mm long (without awn), 1–1.1 mm wide. Upper glume 0.5–1.5 mm long. Lower lemma 4–5.5 mm long. Upper lemma body 4–5.5 mm long, awn 2–2.6 mm long; palea 3–3.8 mm long.  Anthers 0.3–0.4 mm long. Caryopsis 2–3.5 mm long, 0.7–0.8 mm wide.

Distribution and habitat: Calyptochloa gracillima subsp. gracillima is endemic to central Queensland (Map 1). At its most southern limits, it occurs on a range of soil types e.g. clay under brigalow (Acacia harpophylla F.Muell. ex Benth.) (RE 11.3.1), sandy duplex soils to skeletal soils on laterite and shallow sandy soils on sandstone in ironbark woodland (commonly Eucalyptus fibrosa subsp. nubila (Maiden & Blakely) L.A.S.Johnson) (RE 10.7.7). Other REs represented include 11.5.3 and 11.5.4. Further north it  occurs on mostly lateritic landscapes overlapping with the distribution area of C. cylindrosperma but the two species are rarely seen together. REs represented include 11.7.2 and 11.7.6. C. gracillima subsp. gracillima has a much broader habitat range than C. cylindrosperma, C. johnsoniana and C. gracillima subsp. ipsviciensis, which is also reflected in its broader overall distribution.

Phenology: Calyptochloa gracillima subsp. gracillima flowers from December to March during the wet season. The cleistogamous spikelets are produced over a broader seasonal period.

Notes: Caryopsis germination trials indicate differences between the subspecies of Calyptochloa gracillima. Initial trials have revealed more rapid germination of C. gracillima subsp. ipsviciensis and better seedling survival than for the nominative subspecies.

Conservation status: This subspecies is widely distributed over a large area and is usually common in the habitats where it occurs suggesting this subspecies is Least Concern (IUCN 2001).

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith