Schizostachyum brachycladum (Kurz) Kurz (1870: 89

Sungkaew, Sarawood, Wong, Khoon Meng, Hodkinson, Trevor R., Thammanu, Siriluck, Cheysawat, Somboon & Teerawatananon, Atchara, 2024, Taxonomic revision of the bamboo genus Schizostachyum (Bambusoideae: Melocanninae) in Thailand, with two new species and five new records, lectotypifications and nomenclatural corrections, Phytotaxa 676 (3), pp. 263-286 : 267-270

(2) Schizostachyum brachycladum (Kurz) Kurz (1870: 89 , pl. 6, fig. 2). Figs. 2A–B .

≡ Melocanna brachycladum Kurz (1866: 20) nomen.

Type: — INDONESIA, Java, B. boeloe iedjoc . (lectotype here designated: K [K000290787, digital image!]; isolectotypes: K [K000290785 & K000290786, digital images!]) .

Description: — Culms erect, 6–8(–20) m high, tips slightly arching to drooping; internodes usually green, 25–60 cm long, 5–10 cm in diameter, covered with white wax or glabrous; walls up to 4 mm thick; nodes without prominent nodal line. Culm leaves: sheaths initially greenish to yellowish orange, later pale yellow to brown, 15–20 cm long, apex symmetrical, truncate to concave, base of outer margin without a projection, densely covered with appressed reddish brown hairs on abaxial side; auricles lobed, 2–3.5 mm high, oral setae 4–5 mm long; ligules 1–2 mm high, irregularly toothed, ciliate, or subentire; blades erect, greenish brown with purplish base, broadly triangular, 4–10 cm long, apex stiffly acuminate, base inflated. Foliage leaves: auricles inconspicuous lobes, oral setae 2–6 mm long; ligules up to ca. 1 mm high, subentire to entire; blades 10–42 × 2–7 cm, hairy on abaxial side. Pseudospikelets green, lanceolate, 1–1.8(–2) cm long; rachilla internodes up to 0.3 cm long; fertile florets 1 or 2, 1–1.7 cm long, sometimes with terminal rachilla extension, 0.7–1.1 cm long, and with a terminal vestigial floret 2–8 mm long; rachilla internodes between florets 3–5 mm long; lemmas convolute, 0.9–1.2 cm long, with pale short hairs on the margins near the apex; paleas convolute, 1–1.4 cm long, slightly keeled, keels shortly-hairy. Lodicules 3. Stamens: anthers maroon to purple, 5–6 mm long; filaments free.

Distribution and ecology: —The origin of S. brachycladum has been considered uncertain ( Holttum 1958; Wong 1995) and it is most often cultivated (especially the yellow-culm form) in villages in Peninsular Malaysia and Peninsular Thailand (but not in other parts of Thailand), as well as in some other parts of Southeast Asia. However, seemingly natural populations of sparsely distributed clumps appeared to occur amid good vegetation within some national parks in Nakhon Si Thammarat and Trang provinces, where there is evergreen forest.

Additional specimens examined: — THAILAND: Peninsular. Ranong, La-Un, 27 March 1987, D.D. Soejarto et al. 5828 ( L1328825 ) ; Nakhon Si Thammarat, Khao Luang , 8 April 1996, S. Dransfield et al. SD1392 ( BKF110754 ) ; Lan Saka , 24 August 2004, S. Sungkaew & A. Teerawatananon 259 ( Thailand Natural History Museum) ; Trang, Khao Chong , 16 April 1996, S. Dransfield & P. Sawangchote SD1414 (BKF110753, L0362070 , L0362071 ) . SINGAPORE: Rifle Range Forest , 22 September 2017, R.C.J. Lim SING2017-462 (SING0267834, SING0267835 , SING0267836 ) . MALAYSIA: Selangor, Kepong , 7 November 1980, K.M. Wong FRI28986 (SING0330035, SING0330036 , SING0330045 ) ; the same locality, 22 September 1980, K.M. Wong FRI28968 (SING0330030, SING0330039 , SING0330040 ) ; the same locality, 8 October 1980, K. Saleh FRI28772 ( SING0330037 ) ; near Taiping in Kampong , 28 October 1946, R.E. Holttum s.n. ( SING033028 ) ; Penang, Timur Laut, J. L. Pestana 4 (SING0242844, SING0242852 ) ; the same locality, J. L. Pestana 18 (SING0242849, SING0242853 ) .

Conservation status: —Notwithstanding apparently natural populations of S. brachycladum in the Nakhon Si Thammarat and Trang provinces, we were unable to verify that flowering producing viable seed was present (viable natural clumps of Schizostachyum typically produce seed and planted S. brachycladum clumps are so far known to be seedless). As such, we provisionally regard this species as having a Data Deficient status in conservation terms, although in practice, this species is a much-propagated bamboo in its core Southeast Asian region of the Sundaland countries for its usefulness.

Vernacular name: —ไผ่ ทอง (Phai Thong) for the yellow form or ไผ่โป (Phai Po) for the green form.

Notes: —There are two morphological forms of S. brachycladum , the green-culm form (sometimes with random longitudinal yellow stripes on the internodes) and the yellow-culm form (sometimes with random longitudinal green stripes on the internodes) ( Gilliland 1971; Widjaja & Dransfield 1989; Wong 1995). The yellow-culm form of this species is now very popular as an ornamental bamboo in cities and villages. Although the description made by Wong (1995) reported that there were remnants of culm sheath girdles at nodes, we did not observe this character in our specimens examined or during field observation. Their culm nodes only have a nodal line which is more or less flat.

Nomenclatural notes: — Kurz (1866) first proposed the name Melocanna brachycladum ; however, he mentioned only a location together with the note “ B. boeloe iedjoc etc” without a proper description. As a consequence, it is considered a nomen nudum and invalid from the nomenclatural point of view (see Art. 38.2. Ex. 1; Turland et al. 2018). The name “ Schizostachyum brachycladum ” was subsequently validly published by himself with a full description ( Kurz, 1870). We would like to raise the awareness of treating M. zollingeri β. brachyclada Munro as a synonym of this taxon as Kurz (1868) clearly provided the notion reading “ M. Zollingeri β. brachyclada, Munro, l.c. 134,—certissime non Kurz” which implies that the taxonomic combination of “ Schizostachyum brachycladum ” from Meloncanna brachycladum is not involved in proposing the name M. zollingeri β. brachyclada Munro. Thus, Schizostachyum brachycladum (Kurz) Kurz should be recognized. Three specimens found in K (K000290785, K000290786, K000290787) match the description in the protologue with Kurz’s handwriting. According to Art. 9.17 ( Turland et al. 2018), designating a single gathering of more than one barcoded specimen is considered an incomplete typification. Thus, the lectotypification of S. brachycladum is carried out by designating the specimen with the barcode K000290787 as the lectotype since this specimen has better morphological condition than the other two and the note “ B. boeloe iedjoc ,...” present in the protologue is clearly labeled in the sheet.

Figures

FIGURE 2. (A–B) Schizostachyum brachycladum (Kurz) Kurz. (A) Culm internode with culm leaf; (B) Young culm shoot. (C–D) S. grande Ridl. (C) Young culm shoot; (D) Culm leaf on culm internode. (E–F) S. pergracile (Munro) R.B.Majumdar. (E) Culm internode with culm leaf; (F) Young culm shoot. (G–H) S. zollingeri Steud. (G) Culm leaf on culm internode; (H) Young culm shoot. (I–L) S. chinense Rendle. (I) Clump habit; (J) Young culm shoot; (K) Young culm showing culm leaf characteristics (with concave and inflated apex of the sheath proper, and erect blades) and a node; (L) Flowering branch. (Photographed by A. Teerawatananon & S. Sungkaew).