Thelypteris subg. Goniopteris

Salino, Alexandre, Souza, Maria Gabriela Marques De & Arruda, André Jardim, 2014, Thelypteris indusiata (Thelypteridaceae), a new fern species from Amazonian Brazil, Phytotaxa 156 (5), pp. 279-284 : 283

Key to species of Thelypteris subg. Goniopteris from Amazonian Brazil

1. Costules and veins on abaxial side with sessile stellate hairs ............................................................................................... 2

–. Costules and veins on abaxial side glabrous or with acicular hairs ..................................................................................... 3

2. Lamina gradually reduced into a pinnatifid apex; proximal pair of veins from adjacent segments uniting below the sinus to an excurrent vein and the next pair running at or above the sinus ........................................................................... T. biolleyi

–. Lamina with terminal pinna that resembles a lateral one (conform apex); proximal pair of veins from adjacent segments uniting below the sinus to an excurrent vein, with the next 1–2 pairs either joining the excurrent vein below the sinus or running directly to sinus .......................................................................................................................................... T. pennata

3. Veins anastomosing, forming 3–9 series of areoles between costa and margin or sinus; pinnae crenate or very shallowly lobed less than 1/5 the distance to costae; sori exindusiate .................................................................................... T. poiteana

–. Veins free or rarely anastomosing, forming 1–2 areoles series between costa and margin or sinus; pinnae shallowly to deeply lobed, 1/3 or more (if rarely shallowly lobed less than 1/5 then sori indusiate); sori indusiate or exindusiate ......... 4

4. Proximal pairs of veins from adjacent segments uniting below the sinus to an excurrent vein to sinus; sori exindusiate; sporangia with simple acicular hairs on the capsules and stalks ............................................................................... T. tetragona

–. Proximal pairs of veins from adjacent segments uniting at the sinus or ending blindly below the sinus, without excurrent vein; sori indusiate, rarely exindusiate; sporangia glabrous or with hairs only on sporangial stalks (in T. abrupta ) ........... 5

5. Lamina gradually narrowed distally into a pinnatifid apex .................................................................................... T. abrupta

–. Lamina with terminal pinna resembling a lateral one (conform apex), rarely subconform apex .......................................... 6

6. Veins glabrous on both surfaces; distal vein of proximal pair arising from costa; indusia absent or minute ....... T. juruensis

–. Veins with hairs on both surfaces, rarely glabrous; distal vein of proximal pair arising from costule; indusia conspicuous 7

7. Pinnae 2–4(–5) pairs; pinnae usually entire with crenate margins, rarely incised to 1/3 their width; buds or plantlets absent ................................................................................................................................................................................ T. indusiata

–. Pinnae 7–18 pairs; pinnae incised 1/3–3/4 of their width; buds or plantlets usually present in axils of distal pinnae .......... 8

8. Proximal pinnae with short- to long-cuneate bases; abaxial surface of costae glabrous or with sparsely acicular hairs, and a few furcate hairs ......................................................................................................................................................... T. tristis

–. Proximal pinnae with truncate or oblique bases; abaxial surface of costae moderately to densely pilose with a mixture of acicular, furcate and stellate hairs .......................................................................................................................................... 9

9. Segments with 6–9 vein pairs, proximal 1–2 pairs from adjacent segments ending well below the sinus; veins usually with clavate apices ...................................................................................................................................................... T. amazonica

–. Segments with 10–20 vein pairs, proximal 1–2 pairs from adjacent segments connivent to sinus; veins without clavate apices ......................................................................................................................................................................... T. biformata