Dendrocalamus hirtellus
Dendrocalamus hirtellus Ridl., J. Straits Branch Roy. Asiat. Soc. 73, 1916: 146.
Synonym: Bambusa klossii Ridl., Fl. Malay Penins. v, 1925: 259.
Thai name: no known records.
Malay names: buloh kapor; buluh kapur.
Distribution: THAILAND (South): Provinces of Songkhla and Yala; only three records are known, which are listed as specimens below. — MALAYSIA (Peninsular), in three Malaysian states adjacent to Thailand: Kedah, Perak, Kelantan; in openings in lowland forest. — INDONESIA: Kalimantan (Borneo).
Descriptions:
(1) "Culms up to 15 m. tall by 8 cm. thick, internodes white-waxy when young, top of the culm slender and drooping; culm-sheaths dull orange to yellowish above, green at the base, with pale hairs and white waxy powder when young, soon glabrescent, blade purplish below, green above, narrow, up to 18 x 2.5 cm., acuminate; auricles dark green about 1.5 cm. long by 3 mm. high, with pale bristles 2.5 cm. long; ligule 5 mm., firm; leaf-blades up to 40 x 6 cm. velvety-hairy below, base broadly rounded to cuneate above a stalk of 1 cm.; auricles with a few bristles up to 1.5 cm. long; ligule up to 2 mm. high. … [flowers and seeds described]." — H. B. Gilliland & al., Revised Flora of Malaya, vol. 3, 1971: p. 29 [#1039].
(2) "Culm sheaths green at their base and yellowish to pinkish orange near apex, lowest ones densely covered with dark brown hairs, upper ones with dense loose pale brown hairs, all with copious white wax mixed with the hairs; blade broadly lanceolate, spreading to reflexed; auricles spreading crisped lobes 3–5 mm high, bristly on margin, bristles to 12–24 mm long; ligule 2–9 mm high, the base 1.5–8 mm high, divided into coarse teeth or long bristles 2–4 mm long. Culms to 15 m tall, commonly 6–8 cm diameter, the apical part becoming very slender and attenuated and flexuous; internodes 40–50 cm long, dark green, copiously white-waxy, glabrous generally, with a band of silvery brown hairs below and above each node; lower nodes developing conspicuous verticils of roots. Leaf: blades 10–35 cm long, 2–5 cm wide, pale short-hairy on lower side; stalk 3–7 mm long; auricles small inconspicuous lobes, bristly on margin, bristles 5–10 mm long; ligule a subentire rim 0.5–1 mm high. … [flowers described]." — K. M. Wong, Bamboos of Peninsular Malaysia, 1995: p. 113-114, fig. 56-57 [#1210].
(3) "… caespitose. Rhizomes short; pachymorph. Culms erect; drooping at the tip; 1000–1500 cm long; woody. Culm-internodes terete; distally pruinose. Lateral branches dendroid. Culm-sheaths deciduous; yellow and green; glabrous, or pubescent; with tawny hairs; auriculate; with 3 mm high auricles; setose on shoulders; shoulders with straight hairs; shoulders with 20–25 mm long hairs. Culm-sheath ligule dentate. Culm-sheath blade narrowly ovate to ovate; 18 cm long; 25 mm wide; acuminate. Leaf-sheaths glabrous on surface, or pubescent. Leaf-sheath oral hairs setose; 10–15 mm long. Ligule an eciliate membrane; 1–2 mm long; erose. Leaf-blade base cuneate, or broadly rounded; with a brief petiole-like connection to sheath; petiole 1 cm long. Leaf-blades lanceolate; 20–40 cm long; 30–60 mm wide. Leaf-blade surface pubescent; densely hairy; hairy abaxially. Leaf-blade apex acuminate. … [flowers and seeds described]." — Kew GrassBase [#1335].
Images: Photos in K. M. Wong, Bamboos of Peninsular Malaysia, 1995: p. 114, fig. 56-57 (culms, shoot) [#1210].
Characteristics: The main and distinctive characteristics are culm-internodes and culm-leaf sheaths copiously covered with white wax, culm-leaf blades pinkish orange-green, and foliage-leaf blades pubescent beneath.
Dendrocalamus hirtellus (BS-0550): Young shoot, thickly covered with white wax, culm-leaf blades peach-colored (left), the upper part of a young culm-leaf (center), culm-node, flat and glabrous, the culm-leaf above the node is covered with white wax throughout and soft white waxy hairs on the base, and below the node is a narrow white waxy ring, both wax and hairs are easily removable, as demonstrated in the photo by two small cleared spots (right)
Specimen: BS-0550 [E5] (living plant), near อุทยานแห่งชาติ เขาน้ำค้าง (Khao Nam Khang National Park), Songkhla Province, southern Thailand, coll. by C. S., #3052, 30 May 2010.
Characteristics: Habit moderately tight caespitose, tall and scrambling above. Rhizome pachymorph [n.v.]. Culms straight, erect for 10 m or longer, then arching above and scrambling, ultimate length and diameter not yet known (over 12 m long with a basal diameter of 4 cm in June 2021). Young shoots thickly white-waxy and with patches of reddish-brown hairs; emerge from May/June/July to November. Culm-internodes terete, 43–53 cm long, mid-green when young till mid-age, dull greenish to brownish when old, glabrous throughout, initially somewhat farinose; diameter increasing with height, gradually increasing from base to lower mid-culm up to 57% (e.g., basal diameter 3.5 cm, diameter 5.5 cm on the 8th internode at 3.3 m above the ground), then remaining constant for several meters and gradually decreasing towards the top; walls thick [not yet observed in detail]. Culm-nodes glabrous, flat; sheath scar marginally (1 mm) protruding; supranodal line obscure, without a ridge; with a narrow whitish farinose ring below the sheath scar when young, soon fading; occasionally with short aerial roots on the lowest or two lowest nodes. Branch-buds solitary, triangular-subrotund, present from the lowest node up. Branches few, initially 3, central one dominant but not very thick and much elongating, ascending and then widely arching and perpendicularly hanging down to the ground, or scrambling into nearby vegetation; rebranching; unbranched on the lowest 9–11 nodes (3–5 m from the ground); branching intravaginal. Culm-leaves deciduous. Culm-leaf sheaths 21–23 cm wide at the base, 18–22 cm long, shorter than half internode length; rigid; pale pinkish-orange to peach-colored and copiously covered with white wax when young; basal part with long white velvety waxy hairs; upper part with more or less reddish-brown hairs; wax and hairs easily removable, not persistent, surface almost glabrous and light orange-brown with age; outer overlapping margin 3–6 mm long irregularly pale ciliate, inner wrapped margin eciliate; apex rounded, with its middle part (about 3–4 cm wide) slightly convex-truncate. Culm-leaf auricles conspicuous somewhat waved and irregularly 1–4 mm high rims, higher toward the protruding ends, not extending the sheath margin, blackish when young, margin with few to several up to 23 mm long spreading and lasting pale bristles. Culm-leaf ligule membranous, base irregularly high, to ca. 5 mm, initially light green, soon changing to dark-colored when young, the base extending into pale irregular teeth, a few of them with very slender and short pale bristles; papery, deeply cleft, eciliate, and light straw-colored when dry. Culm-leaf blade coriaceous, caducous, horizontally patent, almost as long as the sheath, pale peach-colored on both surfaces when young, not green; lanceolate to broad-lanceolate; base rounded; apex long-pointed; junction with the sheath 10–12 mm wide, adaxially near the junction hairy, otherwise glabrous on both surfaces. Foliage-leaves 5–7 per branchlet. Foliage-leaf sheaths light green, glabrous or hispid, margins eciliate. Foliage-leaf auricles inconspicuous, with a few (1–3) slender straight pale bristles 3–6 mm long. Foliage-leaf ligule inconspicuous, very short, lower than 1 mm, subentire. Foliage-leaf blades soft, medium-sized, 16–26 × 2–2.7 cm, but can reach larger sizes (ca. 40 cm long by 5 cm wide, seen but not measured), lanceolate, green, glabrous above, pubescent beneath; base rounded to wedge-shaped; apex attenuate; one margin antrorsely scabrous, the other margin antrorsely scaberulous or smooth; midrib proximally slightly prominent and light green on both surfaces; pseudopetiole 2–4 mm long. — Flowers and seeds are unknown.
Uses: Not recorded. The species has ornamental value (e.g., for its heavy white-waxy culm leaves with peach-colored blades) and can be used for landscaping.
Cultivation requirements: Slowly growing under the Chiang Mai climate; in part shade, on heavy soil, moisture-retentive to moist with good drainage.
Provisional identification: BS-0550 is closest to Dendrocalamus hirtellus, but mainly differs from this species by its non-farinose or initially little farinose culm-internodes. Furthermore, in BS-0550, the culm-leaf sheaths are pinkish-orange or peach-colored throughout (hidden by a heavy white-wax cover), with no green parts when young, and the culm-leaf blades are horizontally patent and peach-colored throughout (with no green tint). A culm diameter that conspicuously increases with the culm height has also been observed in all culms of BS-0550. It is currently not clear if all these deviating characteristics are within the species range of Dendrocalamus hirtellus, or if BS-0550 is not conspecific. — Mu Chakkrapong, pers. comm., Facebook, 20–21 Oct. 2017.
Comments: (1) Propagules from clump division initially produce small culms. In BS-0550, such small culms are quite different in appearance from thick culms. In BS-0550, young shoots of small culms are usually dark green and without white wax, and culm-leaves may be persistent or late deciduous; culm-nodes are with a prominent ridge and a clearly marked nodal line. (2) When the clump gets larger and its culms have a bigger diameter (>4 cm), the internodes in young shoots develop some white wax, but this does not last long on the internodes. (3) A culm diameter that increases with the culm height between the base and lower mid-culm has also been observed in some other species (e.g., in the genera Dendrocalamus, Gigantochloa, Melocalamus, Schizostachyum) under cultivation at Baan Sammi: BS-0006, BS-0078, BS-0208, BS-0494, BS-0602, BS-0724. The diameter difference can be seen with the naked eye but is not as impressive as in BS-0550.
Specimen: BS-0557 [-] (living plant), "Balae", อ. กาบัง (Kabang District), Yala Province, southern Thailand, wild, coll. by C. S. #3059, 1 June 2010.
Characteristics: Habit tight caespitose. Rhizome pachymorph, short [n.v.]. Culms straight, erect, pendulous above [ultimate height not yet known]. Young shoots glabrous, deep purplish, culm-leaf blades spreading; emerge in November/February. Culm-internodes terete, mid-green when young, about 36 cm long, glabrous, smooth or scaberulous; diameter 1.3 cm [ultimate diameter not yet known], thin-walled, wall thickness 0.5–1 mm in an internode of 8 mm in diameter, easily splittable. Culm-nodes glabrous, smooth, flat; sheath scar not or less than 1 mm protruding; supranodal line discernible, with or without a slight ridge, about 5–6 mm above the nodal line. Branch-buds solitary, triangular-subrotund, present from the lowest node up. Branches few, initially 1–3 (4), subequal but the central one slightly dominant; branching intravaginal; rebranching. Culm-leaves deciduous, early deciduous on the upper branched nodes, late deciduous on the lower unbranched nodes. Culm-leaf sheath about 10 cm long, 1/4–1/3 of the internode length, light green to reddish and slightly farinose when young, light straw-colored when dry, glabrous, except its basal part, which is covered by long, somewhat appressed soft brown hairs; margins long brown ciliate, the ciliae dropping off early; apex narrowly concave-truncate, about 5 mm wide. Culm-leaf auricles small, with few, long pale bristles. Culm-leaf ligule short, subentire, eciliate. Culm-leaf blade horizontally patent, narrow-triangular to lanceolate, rather short on the lower culm, caducous. Foliage-leaves (6) 7–10 (12) per branchlet. Foliage-leaf sheath glabrous, green with a reddish tint when young, light straw-colored when dry; margins eciliate. Foliage-leaf auricles small, dark purplish when young, with a few pale bristles. Foliage-leaf ligule short. Foliage-leaf blade glabrous above, pubescent beneath, (15) 23–36 (38) × (1.7) 2.5–5 (6.5) cm; margins antrorsely scabrous or scaberulous; base rounded to wedge-shaped; apex attenuate; midrib proximally prominent on both surfaces, light green beneath; pseudopetiole 2–5 mm long. Flowers and seeds are unknown.
Specimen: BS-0548 [BBG] (living plant), near อุทยานแห่งชาติ เขาน้ำค้าง (Khao Nam Khang National Park), Songkhla Province, southern Thailand, coll. by C. S., #3050, 30 May 2010.