Guadua paniculata Munro (1868: 85)

Lopes-Neto, Raimundo Balieiro & Viana, Pedro Lage, 2022, Flora of the Serra do Cachimbo (Eastern Amazon, Brazil): Bambusoideae (Poaceae), including the description of two new species, Phytotaxa 550 (2), pp. 99-129 : 110-111

Guadua paniculata Munro (1868: 85) . Fig. 2 O–R .

Lectotype (designated by Lizararu et al. 2013):— BRAZIL. Pernambuco: Rio Preto, Gardner 2981 (lectotype P, isolectotypes B, BM, G, K, MO, P, TCD, US) . Syntype:— BRAZIL. Inter Porto Imperial et Junil, ad flum. Tocantins, 1869, Burchell 8852 [BR, K, P, US-79109 (fragment ex BR)] .

Rhizomes not seen. Culms 5–12 m long, 1.5–2.2 cm in diameter, erect at first then arching at the apex, internodes 22–34.6 cm long, hollow or pithy in center, smooth, glabrous, light green, infranodal bands of white trichomes 4–7 cm long, supranodal bands 0.9–1.2 cm long, both with adpressed, white short trichomes; primary buds subequal, prophyll not seen; nodes stramineous, glabrous, horizontal, supranodal ridge slightly conspicuous. Branch complement with one dominant branch ca. 32 cm long, ca. 6 mm in diameter, internodes 4–8.5 cm long, with 4–16 secondary branches at its base, ca. 16 cm long, ca. 0.5 mm in diameter, internodes ca. 4.1–4.7 cm long. Culm leaves caducous, but the blade falling first; sheaths ca. 21–29.1 cm, longer than the blade, stramineous, abaxially glabrous, adaxially sparsely pubescent, with retrorse trichomes on both surfaces, margins glabrous; auricles absent or inconspicuous; fimbriae ca. 4 mm long, glabrous; inner ligules ca. 0.2 mm long, symmetrical, membranous; blades 9.5–11 × 7–7.5 cm, triangular, stramineous, abaxially glabrous, adaxially pubescent between nerves, densely pubescent at the base, margins ciliate, apex acute. Foliage leaves 6–13 per complement; sheaths 4.3–6.7 × 4 cm, green, glabrous to shortpilose, overlapping margins glabrous, underlapping margins ciliate; auricles absent, when present, format, 5–6 mm; fimbriae 4–5 mm, straight at the base and sinuous toward the apex, stramineous (in siccus); inner ligules ca. 0.3 mm, symmetrical, membranous; outer ligules ca. 0.1 mm, symmetrical, membranous-ciliate; pseudopetioles ca. 0.6 mm, flat, glabrous; blades 15.5–17.5 × 0.8–1.4 cm, linear-lanceolate, green, short pilose on both surfaces, 12–15-nerved, midnerve slightly excentric, 5–7 nerves on one side and 6–8 on the other side, base truncate, margins scabridulous, apex acuminate. Synflorescences 30–58 cm long, paniculate, lax, with 4–8 coflorescences, each coflorescence with 3–8 pseudospikelets, main axes pubescent; subtending bracts ca. 2.2 × 0.8 mm, persistent, triangular, short-pubescent, margins ciliate, densely ciliate toward the apex, apex acute. Pseudospikelets 26–30 × 3.5–4 mm, linear-lanceolate; 3–4 × 1–1.2 mm, symmetrical, triangular, glabrous, margins glabrous, apex acute; gemmiparous bracts ca. 4–5 × 2 mm, subequal, triangular, 10-nerved, stramineous (in siccus), glabrous, margins ciliate, apex acuminate; rachilla internodes between the fertile anthecium ca. 2 mm long, short-ciliate, straight. Fertile anthecium 4–6.7 × 1.8 mm, lanceolate; lemma 12-nerved, glabrous, margins ciliate, apex acuminate; palea 2-keeled, concave between the keels where the rachilla segment fits, 2 inconspicuous wings around the floret, 5-nerved between the keels and 2-nerved in each wing, glabrous except the short-ciliate keels, margins glabrous, apex acute; lodicules not seen; stamens 3, filaments ca. 2 mm long, glabrous, anthers ca. 5 mm long, yellow (in siccus); ovary ca. 0.5 × 1 mm, umbonate, short-pilose toward the apex, style ca. 1.5 mm long, stigma 2. Caryopsis not seen.

Specimens examined: — BRAZIL. Pará: Altamira, BR-163, borda da estrada, a 49 km ao sul de Cachoeira da Serra , 491 m, 8°59’41.3”S, 54°58’31.6”W, 25 May 2021, Lopes-Neto et al. 692 ( MG) ; Reserva Biológica Nascentes da Serra do Cachimbo , Cachoeira do Curuá, ca. 600 m da BR 163 - Santarém-Cuiabá, 333 m, 8°44’01.0”S, 54°57’42.8”W, 30 September 2019, Pastore et al. 1200 ( MG) ; ibidem, 350 m, 8°44’04”S, 54°57’42.8”W, 27 May 2021, Lopes-Neto et al. 763 ( MG) .

Additional specimens examined: — BRAZIL. Mato Grosso do Sul: Porto Murtinho, Fazenda Alto Salobra, próximo aos limites do PARNA da Serra do Bodoquena , estrada p/ Fazenda Califórnia, 20°55’15”S, 56°40’33”W, 03 December 2016, Martinelli et al. 16880 ( MG, RB) .

Distribution and habitat: —This species is distributed from Mexico to South America, in humid to seasonally dry habitats bellow 1,000 meters ( Londoño & Judziewicz 1991). In Brazil, it can be found in the Amazon, Cerrado and Mata Atlântica phytogeographic domains, in the North (AC, PA and TO), Northeast (AL, BA, PE, PI, RN and SE), Central-West (DF, GO, MT and MS), Southeast (ES, MG and SP) and South (RS and SC) regions ( Shirasuna et al. 2020). In the Serra do Cachimbo, this species was found in anthropogenic areas and Open ombrophilous forest.

Comments: — Guadua paniculata is a polymorphic and poorly known species ( Londoño & Judziewicz 1991). It can be distinguished from the other bamboos from the Serra do Cachimbo by the branch complement bearing thorns and caducous culm leaves, the blades falling first, the blades erect and triangular. To distinguish it from E. capitatum , see comments of this species.

Figures

FIGURE 2. Field photographs of bamboos from Serra do Cachimbo. A–C. Actinocladum verticillatum: A–B. Habit. C. Culm leaves. D–I. Arthrostylidium simpliciusculum: D. Habit. E. Branch complement. F. Culm leaf sheath margins. G. Culm leaf apex. H. Foliage leaf complement. I. Foliage leaf fimbriae. J–N. Eremocaulon capitatum: J. Habit. K. Infra- and supranodal bands of trichomes and culm leaves. L. Foliage leaf fimbriae. M. Synflorescence. N. Pseudospikelets. O–R. Guadua paniculata: O. Habit. P. Infra- and supranodal bands of trichomes and thorns. Q. Foliage leaf complement. R. Culm leaves. Photos: P.L.Viana (A–K, M–O, R) and M.Pastore (L, P).