Bambusa glaucophylla

Thai names: ไผ่เงิน (phai ngoen), ไผ่ลายเงิน (phai lai ngoen), ไผ่ลาย (phai lai).

Indonesian name: Bambu putih.

English name: Malay Dwarf Bamboo.

Distribution: Origin is South-East Asia, but the precise location is unknown. — THAILAND, cultivated. — MALAYSIA, cultivated. — INDONESIA, cultivated. — In cultivation in many tropical and subtropical countries.

Local distribution: Frequently planted in the Chiang Mai area; offered for sale at Kham Thiang Market almost throughout the year.

Culm size: Height 4.5–5 m, diameter 2.5 cm.

Descriptions:

(1) "Shoots green, glabrous or covered by brown hairs. Culms 5 m high, straight to slightly zigzag, green with brown hairs when young becoming glabrous, with erect tips; branching just above the ground, branches 3-5 at each node; internodes 20-25 cm long by 1.5-2.5 cm diameter; walls 5-8 mm thick. Sheaths of culm leaves deciduous, 8-12 cm long, covered by brown to black hairs; auricles slightly curved outward, rounded, 2 mm high, edge with 2-3 mm long bristles; ligule entire, 1-2 mm high, glabrous to minutely hairy on the edge; blade erect, triangular, base narrow, adaxially glabrous. Leaf sheath sometimes with black to white hairs; auricles rounded and out curved, 1-2 mm high, glabrous; ligule entire, 1 mm high, glabrous; blades 5-12 X 1-1.5 cm, glabrous, green with longitudinal white stripes. Inflorescences unknown." — E. A. Widjaja, 1997: 59 [#1352].

(2) "… caespitose. Rhizomes short; pachymorph. Culms erect; straight, or zigzag; erect at the tip; 500 cm long; 15–25 mm diam.; woody. Culm-internodes terete; with small lumen; 20–25 cm long; mid-green; distally glabrous, or pilose. Lateral branches dendroid. Buds or branches present on lower quarter of culm. Branch complement three, or several. Culm-sheaths deciduous; 8–12 cm long; hispid; with dark brown hairs, or black hairs; auriculate; with 2 mm high auricles; ciliate on shoulders; shoulders with 2–3 mm long hairs. Culm-sheath ligule 1–2 mm high; entire, or lacerate. Culm-sheath blade triangular; constricted at base; erect; glabrous on surface. Leaves cauline. Leaf-sheaths glabrous on surface, or pilose; hairs white, or black. Leaf-sheath oral hairs lacking. Leaf-sheath auricles falcate; 1–2 mm long. Ligule an eciliate membrane; 1 mm long. Collar with external ligule. Leaf-blade base with a brief petiole-like connection to sheath. Leaf-blades lanceolate; 5–12 cm long; 10–15 mm wide; mid-green; variegated (white stripe). Leaf-blade surface glabrous. Leaf-blade margins scabrous. Leaf-blade apex acuminate. [Flowers unknown]" — Kew GrassBase [#1335].

Images: Photos in BambooWeb.info [#1340].

Comments: The epithet, glaucophylla, derives from Latin glaucus, meaning bluish green or bluish gray, and Greek φύλλον (phyllon), leaf. However, the leaves of this species do not have any bluish tones.

Specimens: BS-0198 [N4], RFR-016 (living plants).

Characteristics: Culms 4.5–5 m high, diameter to 2.5 cm. Foliage-leaf blades small, 5–12 × 1–1.5 cm, green with white to cream stripes. Otherwise like the green leaf variety.

Uses: Plants as garden ornamentals and for dense hedges of low to moderate height, or as potted ornamental plants; easy to prune to the desired shape.

Cultivation requirements: Easy-growing in loamy moist soil with good drainage, exposed to full sun. Does not grow well in shade.

Comments:

(1) The species was originally described to have white striped leaves, which is a quite stable character, but plants may occasionally revert to green leaves.

(2) It has been assumed that Bambusa glaucophylla may be conspecific with Bambusa hetero­stachya (Muller, 1999; cf. K. M. Wong, 2004: 68). However, Bambusa heterostachya differs from the green-leaved variety of Bambusa glaucophylla mainly in the following characteristics (KewScience POWO, accessed 26 Sep. 2021 [#1305]): Culms up to 10 m tall, to 6 cm in diameter, without nodal roots; culm-internodes striped, thin-walled; buds absent from the lower quarter of the culm; culm-leaf ligule 6 mm high, ciliate; foliage-leaf blade base with a brief petiole-like connection to sheath. These differences do not support the presumption of conspecific status.

(3) When a culm of Bambusa glaucophylla is cut above a node, that node reacts by producing several slim branches, and multiple roots on that node, and may even develop a tiny rhizome in the air with a few roots and tiny culms, especially during a season with high atmospheric humidity.

(4) The vegetative morphology of a young Bambusa glaucophylla plant can differ markedly from that of an adult one. As the photos show, the young plants usually completely lack the indument of the culm-leaf sheath, thus the sheaths are glabrous. In addition, the shape of the culm-leaf auricles in young plants is more similar to the shape of the foliage-leaf auricles. The culm-leaf auricles are thus narrower and about twice or thrice as long as they are wide, and the oral setae are absent or poorly developed.

Specimens: BS-0198-1 [W3], BS-0198-2 [-] (living plants, same clone), propagated from BS-0198 by cuttings, 31 Oct. 2008.

Characteristics: Habit unicaespitose, dense. Rhizome pachymorph, short. Culms erect below, straight to slightly zigzag, widely bending outwards above, over 5 m tall, 3 cm (or little more) in diameter [ultimate size not yet known]. Young shoots conical; sheaths green, dark hairy, sheath margins initially brownish green; culm-leaf blades erect to deflexed, medium green; emerge from June to September. Culm-internodes terete, to 44 cm long, medium green, dull, initially scattered with dark brown hairs, becoming glabrous and smooth; walls thick (wall 1.1 cm, cavity 0.8 cm, in a 3.0 cm thick culm at 108 cm above the ground); cavity without pith. Culm-nodes glabrous, smooth, not or slightly prominent; nodal line horizontal; sheath scar marginally protruding 0.5 mm, initially with a very narrow ring (just below the sheath scar) 1–2 mm high of short dark brown hairs; supranodal line discernible, without a slight ridge, 6–8 mm above the nodal line; aerial roots present on the first 2–3 basal nodes. Branch-buds solitary, pointed-subrotund to triangular, from the basal node up, the first 4–6 buds usually remain dormant in mature plants. Branches several, slender, subequal, the central one dominant, usually 1–1.5 m long, upright, then bending downwards; branchless on the first 4–6 nodes of the basal culm; branching intravaginal; rebranching. Culm-leaves deciduous. Culm-leaf sheaths bell-shaped, 12.5 cm wide at the base, 13 cm long, shorter than the internode, leathery, green when young, straw-colored with a reddish tint when drying, dull straw-colored when dry, densely covered with appressed dark brown to blackish hairs, but may be glabrous in a juvenile plant; apex narrowly convex-rounded, symmetrical; margins with short dark ciliae, becoming eciliate. Culm-leaf auricles conspicuous rounded lobes, persistent, equal or somewhat unequal in shape and size, usually 6 mm wide, 5 mm high, erect, not contiguous with the basal margins of the blade, about 5 mm distant from each other, orange-green to green when young, glabrous, margins with short pale waved bristles, waved towards the blade on both auricles, bristles to 5 mm long. Culm-leaf ligule 2–2.5 mm high, convex, denticulate or entire. Culm-leaf blades leathery, erect, deflexed or reflexed, persistent, narrowly long-triangular, near the base 12 mm wide, constricted to 10 mm at the junction with the sheath apex, ca. 4 cm long, glabrous adaxially and abaxially or with very few short dark hairs, green when young, light straw-colored when dry; apex long pointed; margins short dark ciliate or eciliate. Foliage-leaves about 6–11 (14) per branchlet. Foliage-leaf sheaths green to orange-green when young, glabrous, or with a few short blackish hairs; apex truncate, glabrous; margins usually eciliate. Foliage-leaf auricles small glabrous lobes, rounded, erect, somewhat curved outwards, orange-green when young, usually longer than wide, ca. 2 mm long and 1 mm wide, margins short pale waved ciliate. Foliage-leaf ligule inconspicuous, orange-green when young, 0.5 mm high, margin entire; outer ligule inconspicuous. Foliage-leaf blades green, (18) 22–29 (32) cm long, (1.5) 2.5–4 (5) cm wide, somewhat rigid, glabrous on both surfaces, long-lanceolate, upper surface medium green, lower surface minutely glaucous; base rounded to wedge-shaped; apex attenuate; margins antrorsely scabrous; midvein distinct, proximally prominent, light green beneath; pseudopetiole 3–8 mm long.