Dendrocalamus sp. (TH: N) — sang mon

Misapplied name: Dendrocalamus sericeus Munro.

Thai name: ไผ่ซางหม่น (phai sang mon).

English name: Sang Mon Bamboo.

Distribution: THAILAND (Nort, North-East), planted, not rare, no records on wild occurrences known, possibly introduced in early times.

Culm size: Height to 20 (25) m, dia­meter to 15 (18) cm.

Images: Flowering of Dendrocalamus sp. "phai sang mon" in Shan State, Myanmar, 2014, photos by Dr. Cliff Sussman, on Facebook, 29 Jan. 2014. — Flowering of ไผ่ซางหม่น (phai sang mon), Thailand, 2014, on Facebook, 7 Feb. 2014, by Niramit Sareerudt. — Flowering of ไผ่ซางหม่น (phai sang mon), Chiang Dao District, Chiang Mai, northern Thailand, 2014, on Facebook, 7 Feb. 2014, by สวนไผ่นานาพันธุ์ สวน. — Flowering of ไผ่ซางหม่น (phai sang mon), Chiang Dao District, Chiang Mai, northern Thailand, 2014, on Facebook, 23 Aug. 2014, by Yong Bamboo. — Photos of young shoots and basal culms in a clump: Dendrocalamus sp. ไผ่ซางหม่น ฟ้าหม่น (phai sang mon fa mon) compared with Dendrocalamus giganteus ไผ่ยักษ์น่าน (phai yak nan), on Facebook, 28 Apr. 2015, by Thoop Nakasen. — Flowering of "Phai Sang Mon Fa Mon", Thailand, 2017, on Facebook, 6 Feb. 2017, by Thammarat Boonthammee. — Habit of Phai Sang Mon from Mae On District, Chiang Mai Province, on Facebook, 25 Oct. 2020, and 3 Nov. 2020, by Jeera Makmee. — Flowering and seeding of Phai Sang Mon from Chiang Rai Province, northern Thailand, on Facebook, 2 Apr. 2022, by Jeera Makmee.

Characteristics (based on BS-0228 and BS-0264): Habit tight caespitose. Rhizome pachymorph, short. Culms erect, straight upright, strong. Young shoots reddish (orange to pinkish to purplish), scattered short dark hairy; culm-leaf blades almost erect to deflexed, usually not reflexed, reddish-green to dark purplish; emerge from May to September. Culm-internodes relatively short, 7–12 cm on the basal culm, 15–28 (33) cm on the lower culm, 30–40 cm on the mid-culm, 40–27 cm on the upper culm, 27–15–10 cm long on the last 2–3 m to the top, glabrous, smooth, mid-green, powdery white waxy throughout (farinose deposit long lasting though easily removable), thus appearing bluish green, a few basal internodes occasionally much shortened and with oblique nodes; thick-walled (walls 2.1 cm thick in the 4th internode of 7 cm in diameter and 0.7 m above the ground). Culm-nodes glabrous, initially farinose, flat, but slightly prominent on thin culms; sheath scar dark purplish to black when young, 0.5–1 mm protruding; supranodal line obscure, without a ridge, about 5 mm above the nodal line; with a white densely farinose ring 0.5–1.2 (2) cm high below the sheath scar, and 0.4–0.7 (1.5) cm high above the sheath scar, both rings obscure from overall farinose deposit; occasionally with aerial roots on the basal culm. Branch-buds solitary, from the basal node up, broader than tall, 2.5 × 1.7 cm. Branches several, 1 slightly dominant, ascending; branches on the lower culm few and rudimentary, or unbranched, branches usually from the 16th to 21st (37th) node upwards; branching intravaginal, basipetal (from the top toward the lower culm). Culm-leaves early deciduous. Culm-leaf sheath leathery, 23 cm wide at the base, 37 cm long, green to reddish green with light green to yellowish green stripes when young, light reddish brown or light reddish straw-colored when dry, with a few short stiff dark brown hairs chiefly on the upper part of the sheath, otherwise glabrous; margins eciliate, or pale ciliolate initially on the upper margin; apex symmetrically rounded, slightly concave at the junction with the blade. Culm-leaf auricles very low, waved and slightly outwards bent glabrous stiff rims, each extending from the basal edge of the blade toward but not reaching the margin of the sheath, blackish when young; bristles none. Culm-leaf ligule rather high, (5) 7–11 mm, purplish when young, dark straw-colored when dry, margin irregularly toothed, the teeth at the ends of the ligule somewhat higher, without bristles. Culm-leaf blade small, about one-fourth of the length of the sheath, long and narrow, glabrous, dark purplish green when young, dark grayish when dry, persistent to the sheath, usually erect or nearly so at the lower culm, reflexed from the mid-culm up; margins not or slightly convolute toward the apex. Foliage-leaves (5) 7–12 (14) per branchlet. Foliage-leaf sheath keeled, yellowish green when young, glabrous; margins eciliate. Foliage-leaf auricles inconspicuous, very low rims, less than 0.5 mm high; bristles none. Foliage-leaf ligule 2–3 mm high, convex-rounded, yellowish green to orange green when young, reddish with age; margin entire or subentire. Foliage-leaf blades firm, mid-green to dark green above, slightly dull mid-green or bluish green beneath, medium-sized, (15) 23–33 (39) × (1.5) 3–4 (4.7) cm, lanceolate, glabrous on both surfaces; base rounded to wedge-shaped; apex acuminate to attenuate; margins antrorsely scaberulous to smooth; midrib proximally prominent on both surfaces, light green beneath; side veins 4–9 pairs, not tessellate; pseudopetiole 4–6 mm long.

Uses: Culms for construction, house construction, furniture, and for making chopsticks and toothpicks (in Uttaradit); plants for landscaping, suitable for tall screening.

Cultivation requirements: Easy-growing, thrives well in heavy, moist soil with good drainage; flood-tolerant, seems to prefer rich soil and a cool, humid climate.

Provisional identification: Sang Mon Bamboo is similar to Dendrocalamus giganteus but distinct enough in vegetative characteristics so that they could be kept separate easily (→ Table 1, below). Culms of Sang Mon Bamboo are less tall and smaller in diameter than Dendrocalamus giganteus, but stiffly erect (less so, or basally slightly ascending, or apically bending in Dendrocalamus giganteus), culm-internode length is shorter on the basal, lower, and mid-culm. In Dendrocalamus giganteus, there is a narrow brown hairy ring below and above the sheath scar, but these hairy rings are absent in Sang Mon Bamboo. The culm-leaf of Sang Mon Bamboo is similar to Dendrocalamus giganteus in shape and general appearance. I detected neither significant differences in their culm-leaf auricles nor their culm-leaf ligules. In Sang Mon Bamboo, the sheath is a little less thick, hairs on the abaxial surface are fewer, and the blade is initially erect to deflexed (deflexed to usually reflexed in Dendrocalamus giganteus). The foliage-leaf blades of Sang Mon Bamboo are medium-sized (whereas they are larger both in length and width in Dendrocalamus giganteus). Further, there are differences in the shape of the foliage-leaf sheath apex and ligule, which have a long acute extension on the edge of the sheath apex in Dendrocalamus giganteus (lacking in Sang Mon Bamboo). That distinction in characteristics was observed in one nearly mature plant, in two immature plants of Dendrocalamus giganteus, and in more than 3 mature plants of Sang Mon Bamboo, all of them from different locations in Thailand. Further investigation and comparison with more material from different sources are needed to get better proof of these characteristics. The recent flowering of Sang Mon Bamboo could make further investigation of its generative characteristics possible. However, it is currently only known that the spikelets of Sang Mon Bamboo are much smaller than those of Dendrocalamus giganteus, and that the Sang Mon Bamboo is not listed in the Flora of China (Sarawood Sungkaew, pers. comm., Facebook, 28 Dec. 2017).

Comments:

(1) In printed and online publications, the Thai name, ไผ่ซางหม่น (phai sang mon), is often found associated with the botanical name, Dendro­calamus sericeus Munro (in Trans. Linn. Soc. London 26(1), 1868: p. 148-149 [#1251]). However, Dendrocalamus sericeus was described from plants grown on the Parasnath Hill, Giridih District of Jharkhand State (close to Bihar State) in eastern India (located within the former Bengal of British India), and is apparently closely related to Dendrocalamus strictus, and not to the Sang Mon Bamboo. Recently, Dendrocalamus sericeus has been investigated and relegated into the synonymy of D. strictus by a botanist from India (→ Dendrocalamus strictus var. sericeus). In the description of Dendrocalamus sericeus Munro, the following characteristics do not match those of Sang Mon Bamboo: "… Culm-internodes … solid. … Culm-sheaths hispid; hairy on margins. Culm-sheath blade triangular; acute. Leaf-sheaths … pilose. Ligule a ciliate membrane. … Leaf-blades … 17-25 mm wide. … Leaf-blade surface pubescent; hairy on both sides. Leaf-blade margins scabrous. Leaf-blade apex acuminate." (KewScience POWO, accessed 9 Feb. 2020 [#1305]).

(2) The Sang Mon Bamboo may be provisionally referred to as "Dendrocalamus sericeus hort. siam. (non Munro, 1868)", until further investigations have been carried out. Possibly, only a molecular study could reveal the assumed degree of relationship between the Sang Mon Bamboo and Dendrocalamus giganteus and other similar species such as Dendrocalamus brandisii. A molecular study would be required to decide whether the Sang Mon Bamboo should be relegated into the synonymy of Dendrocalamus giganteus, deserves an infraspecific status as subspecies or variety, or should be named as a new, distinct species.

(3) There exist several named selections of the Sang Mon Bamboo, which might not even deserve cultivar status. Not all their characteristics could be observed in detail because some clones were immature and were no longer kept in cultivation at Bambusetum Baan Sammi. I consider the "forms" of Sang Mon Bamboo as different clones (listing of clones see below) and neither as cultivated varieties nor infraspecific taxa such as a forma or a varietas. The brief descriptions as published by the collector Somjit [#1105] do not provide characteristics that could discriminate the clones for doubtless identification, and the features (length dimensions) are within the species' natural range of growth. — Somjit, s.a., ไผ่ซางหม่น [phai sang mon]. Retrieved from http://www.somjitbamboo.com/, translated and annotated by D. Ohrnberger, unpublished draft 8 Nov. 2015 [#1105a].

(4) There are several records that the Sang Mon Bamboo is flowering in northern Thailand, possibly single plants only, but no mass flowering. I have seen one cultivated plant of Sang Mon Bamboo (cl. Siad Fa) gregariously flowering in Chiang Dao in January 2010, but specimens or photos were not taken. In July 2011, I received several small plants (BS-0021) that derived from a former vegetative propagation of cl. Siad Fa. A few plants flowered and died thereafter; a few seeds could be collected from a single flowering plant, and seedlings raised (→ cl. Siad Fa). Another small plant of cl. Fa Mon flowered in 2015 and died thereafter, but neither seeds nor seedlings could be found (→ cl. Fa Mon).

(5) The flowering cycle is unknown. Seed viability is unknown, but viability is assumed to last at least several months.

Thai name: ไผ่ซางหม่น ดอยหลวงเชียงดาว (phai sang mon doi luang chiang dao); "doi luang chiang dao" = name of the tallest mountain in the Chiang Dao District of Chiang Mai Province.

Specimens: BS-0025 [BBG], BS-0415 [BBG] (living plants), no longer kept in cultivation at Bambusetum Baan Sammi.

Characteristics: Not observed.

Uses: Culms for house construction and furniture.

Comments: Characteristics attributed to that clone by Somjit [#1105a] and by other sources: Culms strong, evenly straight throughout, height 12–18 m; culm internodes with thicker diameter than other clones, up to 18 cm thick, wall on the lower internodes 2.5–3.8 cm thick (less than cl. Doi Nang); shoots emerge in April.

Thai name: ไผ่ซางหม่น ดอยนาง (phai sang mon doi nang); supposedly, "doi nang" is the name of a mountain in the Chiang Mai Province.

Images: Post and photos by ชมรมคนรักไผ่ แห่งประเทศไทย (Thai Bamboo Lovers' Club), on Facebook, 1 Jan. 2014.

Thai name: ไผ่ซางหม่น ฟ้าหม่น (phai sang mon fa mon); "fa mon" = dark blue, gloomy sky.

Culm size: Height 15–25 m, diameter of 10–15 cm.

Images: Post and photos by ชมรมคนรักไผ่ แห่งประเทศไทย (Thai Bamboo Lovers' Club), on Facebook, 1 Jan. 2014 [25 Mar. 2022: Content no longer available]. Post and photos by Jeera Makmee (in สมาคมไผ่ไทย Thailand Bamboo Society), on Facebook, 25 Mar. 2022.

Comments: Jeera Makmee distinguishes between ไผ่ฟ้าหม่น (phai fa mon) and ไผ่ซางหม่น (phai sang mon). The distinguishing characteristics can be seen in 12 photos and are as follows: In Phai Fa Mon, the spikelets are smaller, 10–12 mm long, whereas in Phai Sang Mon larger, 17–19 mm long; the basal internode lengths are longer in the former and shorter in the latter; young shoots have initially twisted, purplished culm-leaf blades in the former and are pale and non-twisted in the latter; the culms have no low branching in the former but low branching of small and rudimentary branches are present in the latter (Jeera Makmee, on Facebook, 25 May 2024).

Thai name: ไผ่ซางหม่น แม่ปิง (phai sang mon mae ping); "mae ping" means Ping River.

Thai name: ไผ่ซางหม่น เสียดฟ้า (phai sang mon siat fa); "siat" = to pierce; "fa" = sky.

Culm size: Height up to 25 m, diameter to 18 cm.

Images: Post and photos by ชมรมคนรักไผ่ แห่งประเทศไทย (Thai Bamboo Lovers' Club), on Facebook, 1 Jan. 2014.

Specimens: BS-0021 [†] (living plants), cult., from nursery สวนลุงสมจิตร Somchit, Chiang Dao District, received as "ไผ่ซางหม่น เสียดฟ้า (phai sang mon siat fa)", 28 July 2011; a first plant flowered in Oct. 2011 and died without producing seeds, a second plant flowered from mid-June 2012, produced seeds and died in March 2013, a third plant flowered from July 2012, produced seeds and died in 2013; BS-0021A [BBG, SSG] (seeds): less than 30 seeds collected by D. O., from Sep. 2012 to Mar. 2013, the seeds from a single flowering plant BS-0021, seedlings were raised; BS-0345 [BBG] (living plant), cult., from Somchit, Chiang Dao, 5 Dec. 2009, non-flowering so far (Oct. 2017).

Characteristics: Young shoots and culms were observed, but there is no significant difference in characteristics between these clones and BS-0228. Culm-internodes with walls 2.5–3.8 cm thick.

Uses: Culms for construction and furniture making; shoots used locally for food.

Seed weight: 1 g ≈ 6–7 dried spikelets (husk-wrapped seeds).

Seed germination: 8 seeds (BS-0021A) were laid on moistened tissue paper, on 29 Sep. 2012, 28–30 °C day, with diffuse light, 21–23 °C night, atmospheric humidity >70%, coleoptiles emerged after 4–5 days, all 8 seeds germinated (4 Oct. 2012).

Comments:

(1) Characteristics attributed to that clone by Somjit [#1105a]: Similar to cl. Doi Nang, but culms stronger and taller, height 20–25 m; shoots of good taste, emerge in April; grows well in upland and under drought conditions.

(2) This clone is said to occasionally develop twin culms, and culms to be covered with heavy white wax (not observed).

Thai name: ไผ่ซางหม่น เมีองอุตรดิตถ์ (phai sang mon mueang uttaradit).

Specimens: BS-0190 [E4], BS-0217 [E4], BS-0264 [-] (living plants), cult., all from Kham Thiang Market, Chiang Mai, all received as "ไผ่ซางหม่น" (phai sang mon), 15 Oct. 2008, 16 May 2009, and Sep. 2009.

Characteristics: All of these plants have almost reached their ultimate size, but a significant difference in characteristics between these clones and BS-0228 could not be detected. BS-0264: These specimens occasionally develop basal culms with a much-shortened internode, sometimes with an oblique node, and the culm-internodes of the basal culm are about 2.3 cm thick.

Specimens: none collected (living plant), Thailand, raised from seeds in Chiang Rai Province in 2020.

Characteristics: Culm-internodes with yellowish, brown, and black stripes. Foliage-leaf blades plain green.

Comments: It has not been recorded if this clone reverted to plain green later with maturity. — (Jeera Makmee, จีระ มากมี, pers. comm., Facebook, 21 Aug. 2024).

Specimens: none collected (living plants), Thailand, raised from seeds in Chiang Rai Province in 2022 and 2023.

Characteristics: Culm-internodes initially green, changing to black. Foliage-leaf blades plain green.

Comments:

(1) In 2024, the plants are still young, and it is currently unknown if these clones will revert to plain green later with maturity. — (Jeera Makmee, จีระ มากมี, pers. comm., Facebook, 21 Aug. 2024).

(2) There is another record from 2021 (Jeera Makmee, จีระ มากมี, Facebook, 19 June 2021) of a black-stem Sang Mon bamboo raised from seeds in Phayao Province.