Guadua velutina
Guadua velutina Londoño & L. G. Clark, Nordic J. Bot. 11, 1991: 328.
Thai name: ไผ่กวัดัวนิ่ม (phai kwadwa nim).
Distribution: THAILAND: introduced from the USA, in cultivation, rare. — MEXICO, up to 1,000 m altitude. — USA, cultivated.
Culm size: Height 3–15 m, diameter 5–10 cm.
Description: "Habit: Perennial; caespitose. Rhizomes short; pachymorph. Culms erect; 300-500 cm long; 50-100 mm diam.; woody. Culm-internodes terete; thick-walled; mid-green; distally glabrous. Lateral branches dendroid. Culm-sheaths hispid; auriculate; with 10-40 mm high auricles; setose on shoulders; shoulders with 5-10 mm long hairs. Culm-sheath blade lanceolate; 11-17 cm long; pubescent. Leaf-sheaths pubescent. Leaf-sheath oral hairs setose; 5-10 mm long. Leaf-sheath auricles absent. Ligule an eciliate membrane; 0.3-0.5 mm long. Collar with external ligule. Leaf-blade base with a brief petiole-like connection to sheath. Leaf-blades linear, or lanceolate; 10-20 cm long; 11-22 mm wide. Leaf-blade surface glabrous. Leaf-blade apex acuminate. … [flowers and seeds described]." — KewScience POWO, accessed 10 July 2020 [#1305].
Images: Photos of Guadua velutina from Región Huasteca, Mexico, by E. Ruiz Sánchez on Facebook, 26 Nov. 2019, and 1 Dec. 2019. Photos in BambooWeb1; BambooWeb2; GovardhanGardens; TropicalBamboo.
Uses: Culms for construction.
Guadua velutina (BS-0764): Young culm-leaf
Specimen: BS-0764 [BBG, SSG] (living plant), raised from seeds from cultivated plants in Florida, USA. The plants originate in Mexico. Spikelets were collected in large quantities by R. S., Tropical Bamboo, in 2012, and received on 27 June 2012; not many seeds were found in the spikelets.
Characteristics: Culm-leaf sheaths and foliage-leaf sheaths velvety pubescent.
Seed viability: Unknown.
Seed weight: 10 g ≈ 60–70 dried spikelets (husk-wrapped seeds).
Seed germination: Seeds were laid on moistened tissue paper, in early July 2012, 27–29 °C day temperature, with diffuse light, 24 °C night temperature, atmospheric humidity >70%, coleoptiles emerged after 4 days, germination rate very high (>90%).
Guadua velutina (BS-0764): seed bare of husks (left), germinating seed, 4th day (center), seedling, 16th day (right)
Guadua velutina (BS-0764): About one-third of the total quantity of the harvested spikelets (above), about 24 seeds (0.5 g), bare of husks, collected from all the spikelets (below, left), husks (3.1 g) of all the spikelets (below, right)
Guadua velutina (BS-0764): Seedling, after 7 months