Aulonemia soderstromii P. L. Viana, Filg. & Judz. 2014, sp. nov.
Creators: name: Viana, Pedro L.
name: Filgueiras, Tarciso S.
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Poales
Poaceae
Aulonemia
Aulonemia soderstromii

description: Aulonemia soderstromii P.L. Viana, Filg. & Judz., sp. nov. Fig. 5−6.
Similis Aulonemiae proliferae rhizomatibus amphipodialibus, culmis solidis et spiculis muticis, linearibus ad linearilanceolatas, sed fimbriis effusis admodum in regione ligulari folii (x fimbriis erectis et marginibus vaginae fimbriatis in A. prolifera) differt.
Type:— BRAZIL. Espírito Santo: Linhares, Reserva Biológica de Sooretama, 19°07'S, 40°08'W, 30 m, 15 March 1972 (fl), T.R. Soderstrom 1901 (holotype RB!, isotypes F!, ISC!, INPA!, K, MO!, NY!, SP!, WIS!, US!).
Rhizomes amphipodial. Culms initially erect, decumbent or occasionally creeping, the erect ones becoming clambering on the vegetation, 1.5–8 m long, the decumbent and creeping ones forming new short-necked sympodial rhizomes on nodes in contact with the ground, then becoming leaning on the adjacent vegetation; midculm internodes 12–34.5 × 0.3–1 cm, solid or with a few air canals, terete, glabrous to sparsely puberulous, green to brownish with age, finely mottled, papillose. Nodal line horizontal, glabrous; intranodal area 0.4–1.5 × 0.5–1.2 cm, glabrous; supranodal ridge conspicuous; buds 4–12 × 2–8 mm, oval to oval-lanceolate, glabrous, cataphylls ciliate toward the apex. Branch complement consisting of a single branch that may sometimes bear branchlets on its basal nodes. Culm leaves gradually differentiating into foliage leaves toward the culm apex, sheaths 3.5–9.5 cm long, glabrous, green to purplish; fimbriae 1.3–3.5 cm long; outer ligule present, minute, inner ligule 0.4–0.8 mm long, membranous-ciliolate; pseudopetiole 0.5–1.2 mm, glabrous to pubescent adaxially, glabrous abaxially; blades 5.2–11.3 × 1.2–3.2 cm, oval-lanceolate, reflexed to deflexed, glabrous to puberulous adaxially and abaxially; foliage leaves with sheaths 4.0–8.0 cm long, glabrous to sparsely pilose, ciliate at one margin, slightly keeled toward the apex, green, pale brown or purplish, mottled or not, apical auricular extension absent; pseudopetiole 3–5 × 2–3 mm, glabrous to pubescent on both surfaces, greenish to purplish; fimbriae tardily deciduous, 0.8–2.5 cm long, conspicuously spreading, undulate, apex usually crispate, terete, sparsely scabrous at the base and smooth toward the apex, free or fused at the very base, forming auricles, pale; outer ligule 0.1–0.2 mm long, membranous-ciliolate, inner ligule 0.3–0.6 mm long, membranous-ciliolate; blades (7.5)11–23 × 2.0– 4.5 cm lanceolate to oval-lanceolate, reflexed to deflexed, glabrous, hispidulous or pubescent adaxially, pubescent to sparsely pilose abaxially, chartaceous, regularly green on both surfaces, not clearly tessellate, base asymmetrical, rounded to attenuate, apex acuminate to long-acuminate, margins antrorsely or retrorsely scabrous. Synflorescence 8–19.2 × 6.0– 20.5 cm, an oblong to pyramidal panicle; branches divergent; peduncle glabrous; pedicel 2–13 × ca. 0.2 mm, glabrous. Spikelets consisting of 2 glumes, 2–7 fertile anthoecia and 0–1 apical rudimentary anthoecium, 1.2–3.1 × 0.2–0.6 cm, linear to linear-lanceolate, slightly compressed; glume I 4.8–6.0 mm long, 5–6-nerved, glabrous to puberulous on both surfaces, indumenta denser toward the apex, pale, apex acute, awnless; glume II 6.7–7.5 mm long, 7–9-nerved, glabrous to puberulous on both surfaces - trichomes gathered at the apex -, pale, apex acute, awnless; rachilla internodes 4.2–4.9 mm long, glabrous; lemma 9.0– 10.5 mm long, 8–9-nerved, glabrous to rarely puberulous, scabrous on the nerves and on the margins toward the apex, mottled, apex acute, awnless; palea 8.5–10.2 mm long, 8–11-nerved, glabrous to puberulous between the keels, scabrous on the keels toward the apex, mottled or not, apex acute to navicular. Lodicules oval to triangular, puberulous at the apex; anthers ca. 4 mm long, yellow to pale; ovary ca. 1 mm long, ellipsoid, glabrous. Fruit not seen.
Additional specimens examined: — BRAZIL. Bahia: Boa Nova, Fazenda Alta Mira, 8.4 km E of Boa Nova on road to Dario Meira, then 5 km N on fazenda road, 14°25'16"S 40°06'19"W, 806 m, 18 May 2001 (veg), W.W. Thomas 12472 (SP). Espírito Santo: Ibiraçu, Estação Ecológica Morro da Vargem, 19°53'S, 40°23'W, 470 m, 31 May 1990 (veg), J.M.L. Gomes et al. 1187 (MBML); Santa Teresa, Estação Biológica de santa Lúcia, 19°59'S, 40°28'W, 10 October 2002 (veg), A.P. Santos-Gonçalves et al. 502 (MBML); idem, Estrada Santa Teresa - Vitória, 19°57'13"S, 40°31'52"W, 646 m, 30 December 2007 (fl), P.L.Viana et al. 3183 (BHCB, MBML, IBGE, ISC, MG, MO, NY, RB, SP, SPF); idem, Reserva Biológica de Nova Lombardia, 19°54' S, 40°32' W, 10 May 1985 (veg), F.O. Zuloaga et al. 2434 (BHCB, RB). Minas Gerais: Santa Maria do Salto, Fazenda Duas Barras, 16°24'19"S, 40°03'22"W, 776 m, 24 August 2003 (fl), J.A. Lombardi et al. 5505 (BHCB, HUEFS).
Etymology: —We are pleased to name this new species after the late American agrostologist Dr. Thomas R. Soderstrom, who collected the type material and made invaluable contributions to the knowledge of the Neotropical bamboos.
Comments: —This species was first collected in 1972 by Thomas Soderstrom during a massive flowering event at Reserva Biológica de Sooretama, Espirito Santo state. The numerous specimens collected by him were distributed to several American and Brazilian herbaria and were identified for more than 40 years as Aulonemia aristulata. However, Aulonemia soderstromii is quite distinct from the widespread A. aristulata by its solid culms, effuse fimbriae and awnless spikelets (vs. the hollow culms, erect fimbriae and awned spikelets in A. aristulata).
Like Aulonemia aristulata, A. cincta and A. prolifera, plants of A. soderstromii grow rapidly in clearings and forest borders, propagating aggressively horizontally via amphipodial rhizomes. The species can be readily recognized by its conspicuous effuse fimbriae clusters, which are whitish and can be up to two cm long (Fig. 6C,D). A peculiar feature of A. soderstromii observed in the field (the population documented by P.L. Viana et al. 3183) is the strong fetid smell of its inflorescences, resembling that of a stink bug, a trait not yet recorded for any other bamboo species.
Morphological comparison with related species is provided in the comments under Aulonemia cincta and A. prolifera. Table 1 shows a morphological comparison among the Aulonemia species with amphipodial rhizomes.
Distribution and habitat: —Known from the states of Bahia, Espírito Santo and Minas Gerais, A. soderstromii is probably endemic to the Atlantic rainforest. It was collected in seasonal semideciduous and evergreen forests, usually associated with forest clearings and borders.
Phenology: —Three collections in flower were found among the studied specimens, from 1972, 2003, and 2007. Assuming that the 2003 and 2007 collections (Lombardi 5505 & Viana 3183, respectively) represent a gregarious flowering event, as does Soderstrom’s type collection, in 1972, we suggest a possible flowering cycle of 31 to 35 years. However, as only a few flowering collections are known, these figures are merely speculative.
Conservation: —Not threatened.
description: Published as part of Viana, Pedro L. & Filgueiras, Tarciso S., 2014, Three new species of Aulonemia (Poaceae: Bambusoideae) from the Brazilian Atlantic rainforest, pp. 235-249 in Phytotaxa 156 (4) on pages 244-247, DOI: 10.11646/phytotaxa.156.4.6, http://zenodo.org/record/5128034