Dendrocalamus sp. (TH: N) — pok

• • Thai name: ไผ่โปก (phai pok).

  • Distribution: THAILAND (North).

  • Culm size: Height up to 30 m, dia­meter 17–23 cm.

  • Images: Photos of ไผ่โปก (phai pok) from northern Thailand, by Niramit Sareerudt on Facebook, 24 Jan. 2014.

  • Uses: Culms for construction.

  • Comments:

  • (1) ไผ่โปก (phai pok) is similar to ไผ่ยักษ์ (phai yak, Dendrocalamus giganteus), and ไผ่ซางหม่น (phai sang mon, Dendrocalamus sp.), but is possibly a different species.

  • (2) ไผ่โปก (phai pok) was also assumed to be Dendrocalamus sinicus, but the morphology of the seeds is slightly different. Spikelets and florets of phai pok are shorter, thus looking stout and not slim as in Dendrocalamus sinicus. The culm-leaves are also different. They are thin, papery, and persistent in Dendrocalamus sinicus, whereas in ไผ่โปก (phai pok) they are thick, brittle, and deciduous.

  • (3) Several plants were received under the name ไผ่โปก (phai pok) from different locations in northern Thailand, but their species identification remains unresolved.

  • (4) Flowering of ไผ่โปก (phai pok), a species of Dendrocalamus, was recorded from อำเภอ เชียงแสน (Chiang Saen District) of Chiang Rai Province for about two years, 2018–2019. The vegetative characteristics are between Dendrocalamus giganteus and Dendrocalamus copelandii. Nodes of the lower culm occasionally develop in an oblique pattern in an alternating sequence. — กิตติศักดิ์ จินดาวงค์, pers. comm., 3 July 2021.

• • Specimens: BS-0694 [BBG, SSG], BS-0694-1 [-] (seeds, culm-leaves), living plants raised from seeds received as "ไผ่โปกเล่าจาง (phai pok lao chang)" from cultivated flowering plants, collected in a very low quantity by ธ. ล. in แม่สรวย (Mae Suai District), Chiang Rai Province, northern Thailand, 24 Feb. (BS-0694) and 11 Apr. 2012 (BS-0694-1), and assumed by the collector to be Dendrocalamus sinicus.

  • Seed viability: Unknown, viability is assumed to last at least several months.

  • Seed weight: Not recorded.

  • Seed germination: Seeds (BS-0694) were laid on moistened tissue paper, on 26 Feb. 2012, 29–32 °C day, with diffuse light, 14–23 °C night, atmospheric humidity >70%, coleoptiles emerged after 2 weeks, germination rate low (<40%).

  • Comments:

  • (1) The first seeds were collected from cultivated, some 30 m tall plants. Culms straight, branchless on the lower third of the culm, culm sheaths persistent.

  • (2) Photos taken by ธ. ล. from living plants (flowering and non-flowering clumps) at the collection site were seen by D. O.

  • (3) According to the collector, this species occurs wild and cultivated in northern Thailand, with culm heights up to 30 m, and culm diameters of 17–23 cm, clumper, at high altitudes in moist or moisture-retentive soil, full exposure to the sun, and is assumed to be the same species as BS-0692 from a different location.

• • Specimens: BS-0947 [CS], BS-0947-1 [BBG] (seeds), living plants raised from seeds received as "ไผ่โปก (phai pok)" from flowering plants (Jet Sonthikun on Facebook, 8 May 2021) in May 2021, collected by J. S. in ต. ยางเปียง Yang Piang Subdistrict, อ. อมก๋อย Om Koi District, Chiang Mai Province, northern Thailand, received 20 May 2021.

  • Uses: Young shoots are edible and delicious (acc. to J. S.).

  • Seed viability: Unknown, viability is assumed to last at least several months.

  • Seed weight: 31 dried spikelets (husk-wrapped seeds) = 1.3 g.

  • Seed germination: 5 husk-wrapped seeds and 5 seeds bare of husks set in moistened coir dust, on 21 May 2021, and 21 husk-wrapped seeds set in rich soil, on 30 May 2021. A total of 14 seeds germinated, which led to a germination rate of approx. 45% (seed germination tests 210521 and 210530). Of the 14 seedlings, 9 developed normal green leaf blades (BS-0947), and 5 seedlings were albinos, which is quite a high rate. 4 of the five albinos had no visible or very little chlorophyll, and their leaf blades withered, and the seedlings died shortly afterward. The single remaining albino (BS-0947-1) initially showed a small amount of chlorophyll and was not sure if it could survive. However, the chlorophyll amount of newly developing leaf blades increased significantly, reaching an estimated 90% by late January 2022, and the last developing leaf blade shows a narrow whitish streak. This seedling was then given to Mr. Thammarat Boonthammee (29 Jan. 2022).

• • Specimens: BT0000-17 [BBG] (culm-leaves), coll. in Mae Chan District (อ. แม่จัน), Chiang Rai Province, by Thammarat Boonthammee, received as "Dendrocalamus sp. ไผ่โปก (phai pok), Mae Chan" at Bambusetum Baan Sammi, 31 Jan. 2022. BT0000-18 [BBG] (culm-leaves), coll. in Mae Hong Son Province by Thammarat Boonthammee, received as "Dendrocalamus sp. ไผ่โปก (phai pok), Mae Hong Son" at Bambusetum Baan Sammi, 31 Jan. 2022.

  • Images: Photos of cultivated Phai Pok (ไผ่โปก) in Mae Hong Son Province by Thammarat Boonthammee on Facebook, 28 Dec. 2014.

  • Uses: Culms for construction.

• • Comments: 

  • (1) From the distance, the habit, culms, and culm-leaves of ไผ่โปก (phai pok) from Mae Hong Son resemble Dendrocalamus giganteus and Dendrocalamus sp. "sang mon", and are clearly different from Dendrocalamus sinicus and D. copelandii.

  • (2) The culm-leaves of Phai Pok (ไผ่โปก) from Mae Chan seem to be very similar to those of Mae Hong Son. Noteworthy, there is a slight difference between them on the culm-leaf sheath apex of the adaxial (inner) surface, as is shown in the line drawing: The middle part of the apex is slightly parabolic-raised in the sheaths of Mae Hong Son, whereas the entire apex is evenly concavely shaped in those of Mae Chan.

  • (3) The culm-leaves of Phai Pok (ไผ่โปก), both from Mae Chan and Mae Hong Son are thick, brittle, and, at least on the mid-culm and upper culm, deciduous (perhaps less thick and less brittle in Phai Pok than in Dendrocalamus giganteus), whereas in Dendrocalamus sinicus and D. copelandii, the culm-leaves are thin, papery, and persistent.

All photos of BT0000-17 and BT0000-18 by courtesy of Thammarat Boonthammee.