Schizostachyum dullooa

Synonyms: Teinostachyum dullooa Gamble, Ann. Roy. Bot. Gard. (Calcutta) 7, 1896: 101; type: Myanmar, W. Oliver s.n., K000710261 (lectotype; cf. K. M. Wong in W. L. Goh & al., 2020: 117 [#1309]); Neohouzeaua dullooa (Gamble) A. Camus, Bull. Mus. Natl. Hist. Nat. 28, 1922: 101.

Thai name: ไผ่เฮียะ (phai hia) (Northern). — T. Smitinand, 2001 [#1003]. — A writing variant, ไผ่เฮี๊ยะ (phai hia), with ไม้จัตวา, can often be found in publications.

English names: Dulu Bamboo; Dullooa Bamboo.

Distribution: THAILAND (North): Chiang Mai Province: Doi Suthep – Doi Pui National Park, in the forest at 750–1,075 m altitude (Kew Herbarium [#1333]); Mae On District (อ. แม่ออน) ["Me Awn"], at 350 m altitude; also cultivated; (West): Kanchanaburi, in evergreen forest at 1,500 m altitude; assumed to occur also in the provinces of Chumphon and Ranong of southern Thailand (Classification of Bamboo, 2012 [#1223]). — MYANMAR. — VIETNAM (North). — BANGLADESH. — INDIA (North-East). — BHUTAN.

Culm size: Height 6–9 (10) m, dia­meter 2.5–7.5 cm.

Descriptions:

(1) "Moderate sized to large tufted bamboo, sometimes scandent. Culms variable in size, 6-9 m tall and 2.5-7.5 cm diameter, dark green with a few white hairs. Whitish below the nodes, glossy when dry; nodes slightly prominent; internodes 40-75 cm, sometimes up to 1 m long, with thin walls. Culm-sheaths variable, 12-30 cm long and 10-25 cm broad, striate with white appressed hairs, rounded at the tip somewhat concavely truncate and loosely fringed with bristles; imperfect blade narrow, subulate, recurved, hairy within, edges convolute, 7.5-15 cm long and 0.8-1.8 cm broad; ligule prominent, long, fimbriate. Leaves variable, oblong-lanceolate, acuminate, rounded unequally at the base into a 5-10 mm long petiole, subulately acuminate above, the tip scabrous, twisted, rough on the upper surface, almost glabrous beneath, edges scabrous, midrib not very prominent, secondary veins 6-10 pairs, intermediate ca. 7, transverse veinlets absent but with a few pellucid dots; sheath striate, ciliate on the edges, callus ciliate or glabrous with a few long deciduous bristles, ligule broad, long, fimbriate. …" — K. K. Seethalakshmi & al., Bamboos of India, 1998: p. 240, as "Schizostachyum dullooa" [#1062].

(2) "… Culm-sheaths … with scattered white appressed hairs prominent above. …". "Under this species I have brought together a great series of specimens gathered by various collectors in different parts. These specimens fall rather naturally into two divisions: those of large individuals with rather large leaves, and the small ones with small leaves, the latter being chiefly represented by the type [of Teinostachyum dullooa], the only specimens which give an idea of the character of the flowers. These flowering specimens are those collected in the garden of the monastery at Hawyaw in the Katha district of Upper Burma, in February 1892, by J. W. Oliver. Oliver says that it is a "small reed-like bamboo" named Thaikwaba (Burmese), and that there is a larger variety of the same name. … the genus seems to be this [Teinostachyum], and the species to come rather near, either to the Ceylon T. attenuatum, or to the Burmese Cephalostachyum virgatum. Indeed, when we come to know more of the latter or obtain proper flowers of T. Dullooa, it is not impossible that the two may prove to be identical. … It is possible that when good specimens of the flowers are collected, it will be found that there are two species …; but in my opinion … all the specimens … belong to one and the same widely distributed species. …" — J. S. Gamble, Bambuseae Brit. India, 1896: p. 101-102, as "Teinostachyum dullooa" [#1230].

(3) "… Rhizomes short; pachymorph. Culms erect, or leaning, or scandent; 600–900 cm long; 25–75 mm diam.; woody. Culm-internodes terete; thin-walled; 40–75 cm long; dark green. Lateral branches dendroid. Culm-sheaths 12–30 cm long; 1.2 times as long as wide; pubescent; with appressed hairs; with white hairs; truncate at apex. Culm-sheath ligule fimbriate. Culm-sheath blade linear; reflexed; 7.5–15 cm long; 8–18 mm wide; pubescent. Leaf-sheaths striately veined; outer margin hairy. Leaf-sheath oral hairs scanty; deciduous. Ligule a ciliate membrane. Leaf-blade base asymmetrical; with a brief petiole-like connection to sheath; petiole 0.5–1 cm long. Leaf-blades lanceolate, or oblong; 10–20 cm long; 20–25 mm wide. Leaf-blade midrib evident. Leaf-blade venation with 12–20 secondary veins; without cross veins. Leaf-blade surface scabrous; rough adaxially; glabrous, or puberulous; hairy abaxially. Leaf-blade margins scabrous. Leaf-blade apex acuminate; antrorsely scabrous. … [flowers and seeds described]." — Kew GrassBase, as "Schizostachyum dullooa" [#1335].

Images: Line drawing in J. S. Gamble, Bambuseae Brit. India, 1896: pl. 89; in É. G. Camus, Les Bambusées, Atlas, 1913: pl. 92; in K. K. Seethalakshmi & al., Bamboos of India, 1998: fig. 80, p. 241 [#1062]. Photo of the type specimens at Kew Herbarium (leaves, culm sheath, flowering branches) [#1333]. Photos in bambootech.org (culms).

Uses: Young shoots edible but not popular for food. Culms for kite frames and small boxes, split culms for wickerwork, basketry, mats, walls, and bowls made of bamboo strips. Plants suitable for untrimmed hedges and privacy screening.

Flowering and seeding:

(1) Flowering of ไผ่เฮี๊ยะ (phai hia) in Nan Province, northern Thailand, 24 and 30 Jan. 2014: The young flowering branches in these photos don't show a capitate spikelet arrangement. Recently, a flowering specimen from northern Thailand was received (BS-0148), which clearly shows a species of Schizostachyum s.s. (syn. Neohouzeaua), but not Cephalostachyum (now Schizostachyum s.l.). This specimen neither matches the illustrations of flowering branches of Cephalostachyum virgatum from Myanmar in Kew Herbarium, K000912129 and K000912128 [#1333], nor the illustrations of culm-leaves, flowering branches, and leafy branches from Thailand in Chiang Mai University Herbarium (link to the photos in → Cephalostachyum virgatum, now Schizostachyum virgatum).

(2) Facebook, 24 Jan. 2014, by Niramit Sareerudt.

(3) Facebook, 30 Jan. 2014, by Niramit Sareerudt.

(4) Facebook, 27 Mar. 2014, by Thoop Nakasen.

Cultivation requirements: Easy-growing; in light shade to full sun, sandy loam to clay loam, moisture-retentive to moist soil. It endures some drought but will lose foliage. May not tolerate flooding.

Comments:

(1) At Kew Herbarium [#1333], there are several vegetative and generative specimens of Schizostachyum dullooa (Neohouzeaua dullooa, Teinostachyum dullooa), some recorded from the Chiang Mai Province, both wild and cultivated:  plain at 300 m altitude, Doi Suthep 1,500 m, Mae On 350 m. A further specimen is recorded from Kanchanaburi Province.

(2) It is likely that wild populations of this species, Schizostachyum dullooa, are widespread in northern Thailand, not just in Chiang Mai Province, and they are common in cultivation as well. They are popularly known by the vernacular name ไผ่เฮียะ (phai hia) and are usually identified as Cephalostachyum virgatum or Schizostachyum virgatum.

(3) In some parts of northern Thailand, ไผ่เฮียะ (phai hia) flowered recently. Judging from the inflorescence structure, there seems to be no doubt that ไผ่เฮียะ (phai hia) does not have the capitate inflorescence (as is known, for example, in Cephalostachyum pergracile, now Schizostachyum pergracile); rather, these phai hia species could be genuine Schizostachyum dullooa. However, the culm sheath apex of Schizostachyum dullooa has been described somewhat differently in various publications. The type specimen in the Kew Herbarium [#1333] shows culm sheaths with a horizontally truncate apex, whereas every culm sheath in living plants of ไผ่เฮียะ (phai hia) from Chiang Mai, which I observed, shows a concave-truncate culm sheath apex. Furthermore, ไผ่เฮียะ (phai hia) also shows great similarity with Schizostachyum mekongensis, syn. Neohouzeaua mekongensis, hence the identification of plants named phai hia (ไผ่เฮียะ) has remained unresolved so far.

(4) The line drawing of the culm sheath in Bamboos of India, fig. 80 [#1062], somewhat differs from Gamble's drawing. Therefore, it seems questionable if fig. 80 represents Schizostachyum dullooa. Actually, in fig. 89, Schizostachyum polymorphum (syn. Pseudostachyum polymorphum), the same drawing of the culm sheath as in fig. 80 is displayed. However, this culm sheath certainly does not represent Pseudostachyum polymorphum.

Characteristics (BS-0398): Rhizomes pachymorph, short-necked. Culms erect, bending outwards above. Young shoots conical, with the culm-leaf blades reflexed; emerge from March to August. Culm-internodes dark green to mid-green, with pale soft fuzz when young, straw-colored and rough when old, about 60–106 cm long (possibly longer in mature clumps), thin-walled. Culm-nodes not prominent, with a white ring below the sheath scar when young. Branch-buds solitary, subrotund. Branches in whorls, numerous, thin, subequal, horizontally to slightly ascending. Culm-leaves deciduous. Culm-leaf sheaths much shorter than the internode, about 17 cm long, papery to thinly leathery, sparsely covered with pale appressed hairs; sheath apex concavely truncate, fringed with long pale straight bristles on both sides; the sheath base of one margin (the outer margin) usually with a conspicuous, subcircular projection below the point of attachment. Culm-leaf auricles none. Culm-leaf ligule [not observed]. Culm-leaf blade linear, reflexed, early deciduous, with velvety brown hairs on the upper surface near the attachment to the sheath. Foliage-leaves 3–5 per branchlet. Foliage-leaf sheaths glabrous [or covered with early deciduous pale short hairs], apex with a few 3 mm short straight light brown bristles when young, margins eciliate. Foliage-leaf auricles none. Foliage-leaf ligule inconspicuous. Foliage-leaf blades (23) 33 cm long, (3.5) 5 cm wide, mid-green, glabrous but rough on the upper surface, glabrous and smooth beneath, rounded unequally at the base, margins antrorsely scabrous; midrib prominent, with several secondary veins, without cross veins; pseudopetiole 5–7 mm long, glabrous. Flowers and seeds are known.

Comments: Several seedlings have developed on the ground around the mother plant since August 2024.

Specimen: BS-0110 [-] (living plants), coll. by ศ. ส. #066, as "ไผ่เฮี๊ยะ", northern Thailand, wild, 20 Aug. 2013 (2556 BE), received 26 Aug. 2013.