Corymbia watsoniana subsp. capillata

Yellowjacket

Corymbia | Ochraria

Corymbia watsoniana subsp. capillata (Brooker & A.R.Bean) K.D.Hill & L.A.S.Johnson, Telopea 6: 379 (1995).

Eucalyptus watsoniana subsp. capillata Brooker & A.R.Bean, Austrobaileya 3: 428 (1991). T: Queensland: Leichhardt District: 30.4 miles [49 km] E of Rolleston in Expedition Range, 23 Apr. 1975, M.I.H.Brooker 4833; holo: BRI; iso: AD, CANB, MEL, NSW.

Corymbia catenaria K.D.Hill & L.A.S.Johnson, Telopea 6: 376 (1995). T: Queensland: 10 miles [16 km] from Springsure on Rolleston road, 28 Nov. 1972, D.F.Blaxell 963 & L.A.S.Johnson; holo: NSW.

Tree to 15 m tall. Forming a lignotuber.
Bark rough almost to the smallest branches, thick, soft, loosely flaky to tessellated, yellow-brown to yellow-grey over orange-brown.
Branchlets smooth (glabrous); sometimes have ± elongated oil bodies in the pith.
Juvenile growth (coppice or field seedlings to 50 cm): stem square in cross-section, setose/scabrid until ca 10–15 nodes; juvenile leaves always petiolate, alternate, ovate to lanceolate, 15–21 cm long, 7–12.5 cm wide, base ± peltate for many nodes, well into intermediate phase, apex pointed, green to blue-green, concolorous, dull, setose weathering to scabrid.
Crown entirely of glabrous adult leaves; leaves alternate, petiole 1.3–3.5(4) cm long; blade ovate to broadly lanceolate or falcate, 9–26.5 cm long, (2.3)3–7 cm wide, flat or slightly undulate, base tapering to petiole, apex finely pointed, margin entire, concolorous, dull, green to grey-green, penniveined, densely to very densely reticulate, intramarginal vein parallel to and just within margin, oil glands island, small, numerous, 1 per areole, or obscure.
Inflorescence terminal compound, peduncles 0.6–4 cm long, buds 7 per umbel, usually pedicellate (pedicels 0–1.2 cm long). Mature buds obovoid with operculum scarcely any wider than base of bud, 1.7–2 cm long, 1.5–1.7 cm wide, sometimes slightly ridged, scar present (outer operculum shed early), flattened to rounded and apiculate or umbonate, or beaked, stamens inflexed, anthers ± oblong, versatile, dorsifixed, dehiscing by longitudinal slits (non-confluent), style long, stigma blunt or tapered, locules 3, the ovules arranged in ca 9 ± vertical rows on the placentae or the rows indistinct. Flowers creamy white.
Fruit sessile or shortly pedicellate (pedicels 0–1.4 cm long), barrel-shaped to urceolate or ± cylindrical, 1.5–2(2.3) cm long, 1.2–1.6(1.9) cm wide, disc descending or sometimes level, valves 3, enclosed.
Seeds brown to reddish brown and shiny, 3–8.5 mm long, boat-shaped with a keel on the smooth and sometimes cracked dorsal surface or the keel lacking, not winged but some seed have a short flange at one end, hilum ventral.

Cultivated seedlings (measured at ca node 10): cotyledons reniform to orbicular; stems square in cross-section, setose at least until node 10; leaves always petiolate, opposite for ca 5 nodes then alternate, ovate to ovate-lanceolate, 11–13 cm long, 5–6 cm wide, base rounded with normal petiole insertion until node 5 then petiole inserted peltately into lamina and persisting so for at least 10 nodes, margin entire, apex pointed, dull, green, setae present only on main veins and petioles of leaves throughout seedling growth.

Flowering has been recorded in November.

Corymbia watsoniana is a yellow bloodwood tree species endemic to central Queensland and distributed in the area from Springsure and Rolleston south-east to Eidsvold and near Gayndah, and south to Barakula State Forest. It is a component of dry sclerophyll woodlands on sandy soils in sandstone areas. It has yellowish flaky to tessellated soft rough bark throughout and dull green to grey-green crown of glabrous adult leaves, terminal inflorescences and relatively large fruit. The juvenile leaves vary depending on the subspecies.

There are two subspecies:

C. watsoniana subsp. watsoniana
Has buds with the operculum consistently wider than the hypanthium (base of bud), fruit >1.7 cm wide and juvenile leaves essentially non-setose and not peltate. It occurs from Wigton (S of Gayndah) west to Robinson and Isla Gorges near Theodore, with outliers to the north at Blackdown Tableland, and to the south in the Chinchilla– Pelican area where it occurs in Barakula State Forest.

C. watsoniana subsp. capillata
This subspecies is distinguished from subsp. watsoniana primarily on the juvenile leaves, which are peltate and hairy for many nodes in coppice growth; fruit are somewhat shorter and narrower than in subsp. watsoniana but with some overlap in both dimensions. Buds have opeculum wider than the hypanthium at maturity, but during development this may not be apparent. It is restricted to the Expedition Range and Staircase Range near Rolleston.

The large buds and fruit separate this species from all other yellow bloodwoods, as does the operculum being wider than the hypanthium when fully developed.

Hill & Johnson (1995) described the yellow bloodwood C. catenaria, stating that it differed from C. watsoniana subsp. capillata by the narrower adult leaves, smaller fruit on shorter pedicels and peduncles. We observe that some specimens cited by Johnson & Hill are C. watsoniana subsp. capillata and that the narrower-leaved, smaller-fruited specimens cited represent intermediates between the latter and C. leichhardtii.  

MORE ABOUT CORYMBIA
MORE ABOUT YELLOW BLOODWOODS

Corymbia watsoniana: after Thomas Wentworth Watson, who collected the type specimen in 1876 and sent it to Mueller in Melbourne. Nothing further is known about Watson.

subsp. capillata: Latin capillatus, hairy, referring to the setose seedling growth.