Hidden in the mountain: a new rare Syagrus (Arecaceae) with morphological novelties Author Sant’Anna-Santos, Bruno Francisco 0000-0002-8327-2081 Federal University of Paraná, Curitiba, Brazil Author Lopes Pereira Nunes, Elaine 0000-0002-8317-0472 National Coalition of Independent Scholars, Battleboro, United States of America Author Micheli, Rafael 0000-0002-3890-3737 Federal University of Paraná, Curitiba, Brazil Author Maria Teodoro Francino, Dayana 0000-0002-9160-1893 Federal University of Vales do Jequitinhonha e Mucuri, Diamantina, Brazil text Plant Ecology and Evolution 2025 2025-02-12 158 1 63 81 journal article 308113 10.5091/plecevo.140657 31e22f34-1f27-4554-9e1e-1b8578cb0490

Table 1. Differences in morphology between S. harenae and S. aristeae, S. duartei, S. evansiana, and S. glaucescens.

	Syagrus harenae	Syagrus glaucescens	Syagrus duartei	Syagrus evansiana	Syagrus aristeae
Plant size	Small to moderately-size	Moderately-sized	Small to moderately-sized	Small	Small
Stem size	0.4–1.1 (– 1.4) m × 15–25 cm	0.5–4 m × (8 –) 10–12 cm	0–2 m × 8–12 cm	acaulescent	0.1–0.15 m × 3–9 cm
Leaf vertical rows	Distinct	Distinct	Distinct	Indistinct	Indistinct
Subterranean stem	Prostrate	Erect	Prostrate	Subterranean	Subterranean
Pinnae	Lax	Congested	Congested	Lax	Lax
Leaf rachis	95–167 cm	(55 –) 62–118 cm	50–90 cm	21–92	94–145 cm
Pinnae number	63–79	(38 –) 59–79	44–64	18–48	38–67
Pinnae clusters	2–5	3–5	2–3 (– 4)	2–4 (– 5)	2–3 (– 4)
Ramentas	Present	Absent	Present	Absent	Absent
Tomentum petiole and rachis	Present	Absent	Absent	Absent	Absent
Leaves	8–15	5–15	6–12	3–11	3–6
Sheathing leaf base ca	10–28 cm long	42–52 cm long	20 cm long	10–20 cm long	13–23 cm long
Apical pinnae	8–12 × 0.2–0.4 cm	1.5–6 × 0.2–1.0 cm	6–9 × 0.2–0.8 cm	3–12 × 0.1–0.9 cm	7–18 × 0.6–1.0 cm
Prophyll length	11–16 (– 26) cm	18 cm	18–22 cm	6–16 cm	7–23 cm
Peduncle indumentum	Scattered thin indumentum	Glabrous	Glabrous	Glabrous	Glabrous
Inflorescence	Strongly pendulous	Erect or slightly pendulous	Erect or slightly pendulous	Erect	Erect
Inflorescence	Branched	Branched	Branched	Spicate or branched	Spicate or branched
Flower arrangement	Triads / Tetrads / Pentads	Triads	Triads	Triads	Triads
Staminate flower length at the apex	9–10 mm	8–12 mm	10–15 mm	8–10 mm	10–12.5 mm
Staminate flower length at the base	11.5–14 mm	14–17 mm	16–28 mm	8–10 mm	11.2–15.9 mm
Staminate flower colour	Yellow	Green to yellow	Green to yellow	Yellow	Yellow
Stamen length	5.0–7.0 mm	6.0–8.5 mm	8–10.5 mm	4–5 mm	5.9–9.0 mm
Anther length	4.0–7.0 mm	5.0–7.5 mm	6–9.5 mm	3.5–4.0 mm	4.4–7.7 mm
Filament length	2.0–3.0 mm	1.0–2.0 mm	2.0 mm	1.0 mm	1.3–3.2 mm
Pistillode	0.8–1.0 mm	Less than 1 mm	Less than 0.5 mm	Less than 1 mm	0.5–1.5 mm
Pistillate flowers length	13–17 mm	10–17 mm	17–25 mm	8–19 mm	12.1–16 mm
Number of sepals	2–4	3	3	3	3
Number of petals	3–4	3	3	3	3
Petals tips	Imbricate tips	Valvate tips, 1 / 3 to 4 / 5 the length of the petal	Valvate tips, 1 / 2 the length of the petal	Valvate tips, 2 / 5 to 1 / 2 the length of the petal	Valvate tips, 2 / 5 to 1 / 2 the length of the petal
Pistil size	6–8 × 3–4 mm	6–9 × 4.0–6.0 mm	10 × 4.5 mm	10–11 × 3.5–4 mm	5.8–7.7 × 2.1–3.9 mm
Pistil indumentum	Whitish indumentum on lower 1 / 3	Glabrous	Glabrous or fine wax indumentum	Lepidote indumentum from base to nearly the base of the stigmas	Glabrous
Stigmas	3–4 mm	3–4 mm	6 mm	3–5 mm	2.8–3.4 mm
Staminodal ring	Less than 0.5 mm	0.7–2 mm	ca 0.8 mm	1–3 mm	1 mm
Fruit	Ellipsoid to ovoid	Ellipsoid	Nearly globose	Globose	Nearly globose
Fruit sized	2.1–3.0 × 1.6–2.0 cm	2–3 × 1.6–2.5 cm	3.0–3.8 × 2.5–3.2 cm	1.5 – 2.3 × 1.5–2.3 cm	1.7–2.5 × 1.1–1.9 cm
Fruit colour when mature	Orange	Brown	Brown	Yellowish brown	Yellowish brown
Mesocarp	1–2 mm	1–2 mm	2–4 mm	1–2 mm	1.0–2.5 mm
Endocarp size	1.8–2.0 × 1.2–1.9 cm	2 – 2.8 × 1.7–2.1 cm	3.0–3.5 × 2.8–3.0 cm	1.4–1.6 × 1.1–1.3 cm	1.3–1.8 × 1.1–1.4 cm
Endocarp thickness on the sides	2–3 mm	(2 –) 3–4 mm	5–8 mm	1 mm	1 mm