Corresponding author: Nian-He Xia (
Academic editor: E. Ruiz-Sanchez
Due to their specialised flowering biology where frequent or even annual flowering is uncommon, reproductive materials of bamboos are not always available, so hampering taxonomic interpretation and research into other aspects.
Qin Q-M, Cai Z-Y, Ni J-B, Tong Y-H, Xia N-H (2022) The floral morphology of four Chinese
The subfamily
Phylogenetic studies have shown that
In this study, the pseudospikelet and floral morphology of these four
All flowering materials were collected from plants cultivated in the Bambusetum of South China Botanical Garden, Chinese Academy of Sciences. They are deposited in the IBSC Herbarium of the South China Botanical Garden, as
China, Guangdong Province: Guangzhou City, cultivated in South China Botanical Garden, Chinese Academy of Sciences (plants originally from Guangxi, Dongxing), 15 August 1978,
China, Guangdong Province: Guangzhou City, cultivated in South China Botanical Garden, Chinese Academy of Sciences, 31 March 2016,
Culms 5–6 m tall, 2–3 cm diameter, erect, apically drooping; internodes 34–57 cm long, plain green, initially slightly white waxy, with sparse long white hairs; wall ca. 3 mm thick; nodes flat, glabrous. Branch complement at mid-culm with a slightly dominant central branch and many subequal branches, those at culm base without thorny branchlets. Culm leaf sheath slightly white waxy, usually glabrous or basally dark brown hispid, apically arched with asymmetric sides; auricles unequal, oblong to lanceolate, undulate, wrinkled, larger auricle slightly slanted downwards, ca. 3 cm long, 0.7–1 cm wide, ca. 2 times larger than smaller one, bristles on the margin undulate; ligule ca. 2 mm high, margin sparsely dentate; blade erect, narrowly ovate, ca. 2/5 as long as sheath, base rounded, slightly overlapping with auricles for 2–3 mm, ca. 1/4 as wide as sheath apex, apex involute and acuminate. Foliage leaf sheath glabrous; auricles subovate, margin with long bristles; ligule very low, margin sparsely dentate; blade linear to linear-lanceolate, 10–15 cm long, 1.3–1.5 cm wide, abaxial surface densely pubescent, adaxial surface glabrous. Pseudospikelets fasciculate at each node of flowering branches, linear, sessile, basally subtended by several bud-bearing bracts, 2.5–3.5 cm long; florets 4–6, middle 2–4 florets fully developed; prophylls 1–2 mm long, 2-keeled, keels sparsely ciliolate; bracts 2–4, ovate to oblong, 3–5 mm long, glabrous, apically ciliolate, adaxial surface apex puberulent, obscurely 0–5-veined, apex obtuse to acute, mucronate or not; rachilla disarticulating between florets, segments compressed, 1.5–3 mm long, glabrous, lower segments distally inflated, upper segments distally only slightly inflated; glumes 1–3, oblong, 6–7 mm long, glabrous, sometimes adaxial surface apex puberulent, obscurely 11–13-veined, apex obtuse to acute, mucronate or not; lemma oblong, 7–10 mm long, glabrous, abaxial surface purple-spotted, 19–21-veined, apex acute mucronate, calluses no more than 5 mm long, glabrous; palea 9–11 mm long, 2-keeled, keels apically ciliolate, 4–5-veined between keels, each side 2-veined, apex truncate; lodicules 3, apex ciliate, anterior two broadly oblong, 2–3 mm long, posterior one narrowly oblong, 2–3 mm long; stamens 6, filaments filiform, anthers brown to yellowish, 5.5–7 mm long, apex retuse; ovary obovoid, 1.8–2 mm long, apex hispidulous, styles 3, 0.5–0.7 mm long, stigmas 3, plumose, 4–5 mm long.
Vegetative morphology and pseudospikelets of
Floral morphology of
We made a comparison between this species and its relative,
China, Guangdong Province: Guangzhou City, cultivated in South China Botanical Garden, Chinese Academy of Sciences (plants originally from Guangxi, Dongxing), 15 August 1978,
China, Guangdong Province: Guangzhou City, cultivated in South China Botanical Garden, Chinese Academy of Sciences, 31 March 2016,
Culms ca. 8 m tall, 4–7 cm diameter, basally slightly zig-zag, apically drooping; internodes 20–32 cm long, basal ones conspicuously shorter, usually flat and shallowly grooved above branches, plain green, initially white waxy and with caducous sparse hispid hairs; wall ca. 8 mm thick; basal nodes with grey-white sericeous ring-like zones below and above sheath insertion, with short aerial roots. Primary branch bud horizontally elliptic, prophyll margins apically ciliate. Branch complement at lower culm nodes typically with only one branch bearing short, curved, weak, thorny branchlets; at mid-culm with 3 to several branches, central branch dominant. Culm leaf sheath glabrous, apex subtruncate, with a triangular protuberance on one shoulder; auricles unequal, lager auricle oblong or elliptic, ca. 8 mm wide, ca. 3 times larger than smaller one, margin with undulate bristles ca. 1 cm long; ligule ca. 3 mm high, short-fimbriate; blade erect, triangular or narrowly ovate, base 4/5 as wide as sheath apex. Foliage leaf sheath glabrous; auricles absent or tiny, semicircular to ovate, margin with undulate bristles; ligule very low, fimbriate; blade linear to lanceolate, 13–20 cm long, 1–2 cm wide, abaxial surface pubescent, adaxial surface glabrous. Pseudospikelets fasciculate at each node of flowering branches, linear, sessile, basally subtended by several bud-bearing bracts, 2–4 cm long; florets 7–9, middle 2–5 florets fully developed; prophylls ca. 4 mm long, 2-keeled, keels apically sparsely ciliolate; bracts 2–3, lanceolate, 4–6 mm long, glabrous, 1–9-veined, apex acute, mucronate or not; rachilla disarticulating between florets, segments compressed, 2–4 mm long, glabrous, apex ciliolate, lower segments distally inflated, upper segments distally only slightly inflated; glumes 1–3, ovate, ca. 7 mm long, glabrous, adaxial surface puberulent at the upper half, 15-veined, apex acute mucronate; lemma oblong, 8–12 mm long, glabrous, abaxial surface purple-spotted, 18–21-veined, apex acute mucronate, calluses ca. 0.5 mm long, glabrous; palea 8–13 mm long, 2-keeled, keels apically sparsely ciliolate, 4-veined between keels, each side 2-veined; lodicules 3, apex ciliate, anterior 2 obliquely oblong, 2.5–3 mm long, posterior one obovate, ca. 2.5 mm long; stamens 6, filaments filiform, anthers yellow to brownish, 5.5–6 mm long, apex retuse; ovary obovoid, 1.5–2 mm long, apex sparsely hispidulous, styles 3, 0.8–1 mm long, stigmas 3, plumose, 2.5–8 mm long.
Vegetative morphology and pseudospikelets of
Floral morphology of
This species is closely related to
China, Guangdong Province: Guangzhou City, cultivated in Lingnan University Bamboo Garden under BG 1833 (living type, originally from Guangxi, Wuzhou, Cangwu, Changzhou Island, West River, above Wuzhou), 10 September 1933,
China, Guangdong Province: Guangzhou City, cultivated in South China Botanical Garden, Chinese Academy of Sciences, 31 March 2016,
Culms 8–13 m tall, 6–8 cm diameter, basally straight or zig-zag, apically pendulous; internodes 24–28 cm long, slightly curved, basally somewhat swollen, glabrous, plain green, initially slightly white waxy; basal nodes with grey-white sericeous ring-like zones below and above sheath insertion. Branch complement at lower culm nodes with branchlets sometimes specialised into curved, weak thorns; at mid-culm with several branches, central 3 branches dominant. Culm leaf sheath ribbed-striate, with caducous, stiff, appressed, pale hairs above the middle, apex somewhat truncate; auricles equal, oblong, small, margins with fine bristles; ligule up to 3 mm high, entire, margin ciliate; blade erect, triangular to narrowly triangular. Foliage leaf sheath glabrous; auricles absent, without or with only a few bristles; ligule very low; blade lanceolate to oblong-lanceolate, 12–20 cm long, 2–3 cm wide, abaxial surface pubescent, adaxial surface glabrous. Pseudospikelets fasciculate at each node of flowering branches, linear, sessile, basally subtended by several bud-bearing bracts at base, 2.5–4.5 cm long; florets 10–12, middle 5–7 florets fully developed; prophylls 2–4 mm long, 2-keeled, keels apically sparsely ciliolate; bracts 2–3, lanceolate, 3–4 mm long, glabrous, apically ciliolate, sometimes adaxial surface apex puberulent, apex acute, mucronate or not; rachilla not disarticulating between florets, segments compressed, 2–3 mm long, glabrous, apex slightly ciliolate and flat; glumes 1–2, lanceolate to oblong, 5–7 mm long, glabrous, both surface apex puberulent, obscurely 11–13-veined, apex acute or obtuse, mucronate; lemma broadly elliptic, 10–12 mm long, glabrous, 19–23-veined, apex acute mucronate, calluses no more than 0.5 mm long, glabrous; palea 8–11 mm long, 2-keeled, keels apically ciliolate, 4–6-veined between keels, each side 2–3-veined; lodicules 3, apex ciliate, anterior 2 obliquely oblong, 3–3.5 mm long, posterior one narrower, ca. 3.5 mm long; stamens 6, filaments filiform, anthers yellow, 5–7 mm long, apex apiculate; ovary broadly ovoid, 1–2 mm long, apex hispidulous, style 1, 0.7–1 mm long, stigmas 3, plumose, 4–5 mm long.
Vegetative morphology and pseudospikelets of
Floral morphology of
China, Guangdong Province: Guangzhou City, cultivated in South China Botanical Garden, Chinese Academy of Sciences (plants originally from Guangdong, Xinyi, Qingshui mountain), 5 August 1976,
China, Guangdong Province: Guangzhou City, cultivated in South China Botanical Garden, Chinese Academy of Sciences, 27 November 2015,
Culms 4–5 m tall, 2–2.5 cm diameter, basally nearly straight, apically slightly drooping; internodes 25–33 cm long, glabrous, initially slightly white waxy, green, basal ones typically with yellow stripes; wall ca. 7 mm thick; basal nodes with grey-white sericeous ring-like zones below and above sheath insertion. Primary branch bud broadly ovate, prophyll margins apically ciliate. Branch complement at mid-culm with many branches, central 3 branches dominant, those at culm base without thorny branchlets. Culm leaf sheath initially green with yellow stripes, glabrous or brown hispid especially near margins, apex subtruncate; auricles unequal, larger one about 2.5 times as large as smaller one, moderately to broadly elliptic, ca. 2 cm long, ca. 1.3 cm wide, wrinkled, margins with undulate bristles; ligule 1.5–2 mm high, margin ciliate; blade caducous, erect, triangular to narrowly triangular, base slightly rounded, overlapping with auricles for 6–7 mm, about 3/5 as wide as sheath apex. Foliage leaf sheath glabrous; auricles subovate or tiny, margin with undulate bristles; ligule low, entire; blade linear-lanceolate, 8–15 cm long, 0.9–1.3 cm wide, abaxial surface densely pubescent, adaxial surface glabrous. Pseudospikelets fasciculate at each node of flowering branches, linear, sessile, basally subtended by several bud-bearing bracts at base, 2.5–3 cm long; florets 9–10, middle 4–7 florets fully developed; prophylls ca. 3 mm long, 2-keeled, keels apically sparsely ciliolate; bracts 4–5, lanceolate, 3.5–10.5 mm long, glabrous, adaxial surface puberulent at the upper half, 5–15-veined, apex acute mucronate; rachilla disarticulating between florets, segments compressed, 4–5 mm long, apex ciliolate and flat; no glume; lemma oblong-lanceolate, 12–14 mm long, glabrous, 17–19-veined, apex acute mucronate, calluses ca. 1 mm long, glabrous; palea 12–13 mm long, 2-keeled, keels apically sparsely ciliolate, 4-veined between keels, each side 2-veined, apex slightly puberulent; lodicules 3, apex ciliate, anterior 2 obliquely oblong, 2.5–3.5 mm long, posterior one narrowly obovate, 2.5 mm long; stamens 6, filaments filiform, anthers brown to yellowish, 5–6.5 mm long, apex retuse; ovary obovoid, ca. 1.5 mm long, apex hispidulous, styles 3, 0.5–0.6 mm long, stigmas 3, rarely 4, plumose, 2.5–3 mm long.
Vegetative morphology and pseudospikelets of
Floral morphology of
After the comparison of floral characters between this species and a very similar congener,
We are grateful to Mr. Ding-Han Cui for preparing the illustrations. This work was supported by the National Natural Science Foundation of China (Grants 31670196), the Science and Technology Program of Guangzhou, China (grant no. 202201011461), the Young Innovative Talents Project (Natural Science) in Colleges and Universities of Guangdong Province (grant no. 2021KQNCX189) and the Natural Science Project of the Guangdong Eco-engineering Polytechnic (grant no. 2020kykt-xj-zk05).