Geonoma schottiana Martius 1826
Creators: name: Henderson, Andrew
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Arecales
Arecaceae
Geonoma
Geonoma schottiana

description: 56. Geonoma schottiana Martius (1826: 143). Type: BRAZIL. Rio de Janeiro: no locality, no date, H. Schott
4111 (holotype M!).
Geonoma schottiana var. angustifolia Drude (1882: 492). Lectotype (here designated): BRAZIL. Rio de Janeiro: Petropolis, 6 April 1877, A. Glaziou 9011 (lectotype BR!, duplicates K!, FI!, P!).
Geonoma schottiana var. latifolia Drude (1882: 492). Lectotype (here designated): BRAZIL. Rio de Janeiro: Restinga de Mauá, 8 June 1876, A. Glaziou 8493 (lectotype BR!, duplicate P!).
Geonoma hoehnei Burret (1930a: 231). Type: BRAZIL. São Paulo: Japuhyba, 17 April 1926, F. Hoehne & A. Gehrt 17391 (holotype SP!).
Plants 2.9(1.5–6.0) m tall; stems 1.7(0.3–3.5) m tall, in diameter, no data, solitary, cane-like; internodes no data, yellowish and smooth. Leaves 15(7–24) per stem, regularly pinnate, the pinnae with 1 main vein and 2 lateral veins on either side of main vein, not plicate, bases of blades running diagonally into the rachis; sheaths 26.9(23.5–33.0) cm long; petioles 57.8(30.0–87.0) cm long, drying green or yellowish; rachis 70.4(44.0– 118.0) cm long, 5.1(2.6–8.9) mm in diameter; veins raised and rectangular in cross-section adaxially; pinnae 26(10–38) per side of rachis; basal pinna 36.8(17.5–59.0) cm long, 0.5(0.2–2.1) cm wide, forming an angle of 49(25–90)° with the rachis; apical pinna 22.4(12.5–36.5) cm long, 3.0(0.6–10.2) cm wide, forming an angle of 21(7–34)° with the rachis. Inflorescences unbranched or branched 1–3 orders; prophylls and peduncular bracts not ribbed with elongate, unbranched fibers, flattened, deciduous or persistent; prophylls 26.4(16.0– 36.5) cm long, not short and asymmetrically apiculate, the surfaces not ridged, without unequally wide ridges; peduncular bracts 20.2(8.6–31.0) cm long, well-developed, inserted 18.8(5.0–46.0) cm above the prophyll; peduncles 37.7(18.0–73.5) cm long, 5.1(1.6–10.6) mm in diameter; rachillae 16(1–69), 20.6(7.5–37.0) cm long, 1.9(0.7–3.5) mm in diameter, the surfaces without spiky, fibrous projections or ridges, drying brown or yellow-brown, without short, transverse ridges, not filiform and not narrowed between the flower pits; flower pits tricussately arranged, the groups not closely spaced nor consistently arranged throughout the rachillae, glabrous internally; proximal lips without a central notch before anthesis, not recurved after anthesis, not hood-shaped; proximal and distal lips drying darker brown than the rachillae, not joined to form a raised cupule, the proximal lip margins overlapping the distal lip margins; distal lips well-developed; staminate and pistillate petals not emergent, not valvate throughout; staminate flowers deciduous after anthesis; stamens 6; thecae diverging at anthesis, inserted almost directly onto the filament apices, the connectives bifid but scarcely developed; anthers short and curled over at anthesis; non-fertilized pistillate flowers deciduous after anthesis; staminodial tubes crenulate or shallowly lobed at the apex, those of non-fertilized pistillate flowers not projecting and persistent after anthesis; fruits 9.3(7.4–13.4) mm long, 7.5(5.9–10.6) mm in diameter, the bases with a prominent, asymmetric stipe, the apices conical with rounded apices, the surfaces not splitting at maturity, without fibers emerging, not bumpy, not apiculate; locular epidermis without operculum, smooth, without pores.
Distribution and habitat:— From 16°35’– 29°46’S and 39°39’– 51°08’W in the Atlantic Coastal Forest and inland areas of southeastern Brazil (Espírito Santo, Minas Gerais, Paraná, Rio de Janeiro, Rio Grande do Sul, Santa Catarina, São Paulo) at 747(3–1600) m elevation in lowland to montane tropical rainforest or gallery forest (Fig. 37).
Taxonomic notes:— Geonoma schottiana is a member of a group of species from the Atlantic Coastal Forest and adjacent Cerrado (the G. schottiana clade, also including G. elegans, G. pauciflora, and G. pohliana). Although the group is well-supported, all constituent species are extremely variable internally. Geonoma schottiana differs from other species in the group by its regularly pinnate leaves, the pinnae with 1 main vein and 2 lateral veins on either side of main vein.
Subspecific variation:— Only one trait varies within this species (inflorescence branching). One specimen (of 76) has an unbranched inflorescence. There is geographic discontinuity.
Geonoma schottiana occurs in two areas in Brazil—the Atlantic Coastal Forest at 3–1600 m elevation in various habitats including restinga, lowland, and montane forest; and further inland in Minas Gerais in the southern part of the Serra do Espinhaço at 760–1450 m elevation in gallery forest. Specimens from Minas Gerais (minas morphotype) differ from those of other areas (excluding possible hybrids, see below) in 14 variables (plant height, stem height, rachis length, rachis width, number of pinnae, basal pinna length, basal pinna angle, apical pinna length, interbract distance, peduncle length, peduncle width, rachilla length, rachilla width, number of rachillae)(t- test, P <0.05). In particular, minas specimens have shorter interbract distances (mean of 8.9 cm versus 18.2 cm), shorter peduncles (mean of 24.8 cm versus 39.2 cm), and more rachillae (mean of 42 versus 17). The minas morphotype occurs sympatrically with G. pauciflora subsp. weddelliana.
Eleven specimens from the Serra do Castelo in Espírito Santo (castelo morphotype) differ from others from the Atlantic Coastal Forest in 11 variables (plant height, stem height, rachis width, basal pinna angle, peduncular bract length, interbract distance, peduncle length, peduncle width, rachillae length, rachillae width, number of rachillae)(t -test, P <0.05). In particular, these specimens have shorter (mean of 15.6 cm versus 22.2 cm), thicker (mean of 2.6 mm versus 1.8 mm), and fewer (3 versus 17) rachillae than other specimens. One specimen (Kollmann 9579) has only one rachilla. In these variables the castelo morphotype resembles G. elegans, with which it occurs sympatrically. There may be introgression between these two in this area.
One specimen (Fiaschi 613) from Rio de Janeiro has leaves like those of G. pauciflora subsp. pohliana but inflorescences like those of G. schottiana. For other potential hybrids with G. pohliana, see under that subspecies.
description: Published as part of Henderson, Andrew, 2011, A revision of Geonoma (Arecaceae), pp. 1-271 in Phytotaxa 17 on pages 137-138, DOI: 10.11646/phytotaxa.17.1, http://zenodo.org/record/3538362