Rio Abajo maiden fern
Thelypteris abdita Proctor
Rio Abajo maiden fern forms a loose rosette of only a few fronds. Usually four to seven spread outward or recline from a small, short rhizome. Its diminutive proportions persist in mature plants, rather than simply representing young growth of a larger fern. Proctor (1985): New Species of Thelypteris from Puerto Rico, American Fern Journal 75:56–70
Botanical name
Kew accepts Thelypteris abdita Proctor. Goniopteris abdita (Proctor) Salino & T.E.Almeida is a homotypic synonym used in an alternative generic classification. Kew Plants of the World Online: Thelypteris abdita
Recognizing the plant
Fronds are commonly 6–19 cm long. Their narrow blades carry ten to twenty pairs of mostly alternate, stalked pinnae: small, rounded-oblong divisions with smooth margins. Minute star-shaped hairs cover parts of the stalks and blades. The veins remain free from one another, either unbranched or forked once. Each spore-producing cluster has a small covering, the indusium, whose glandular edge and long, mostly simple hairs provide further microscopic distinctions. Brown, pointed scales surround the tip of the rhizome. Proctor (1985): New Species of Thelypteris from Puerto Rico, American Fern Journal 75:56–70
Native range
The species is endemic to Puerto Rico. Its original type was collected in sheltered crevices of a moist, vertical limestone cliff in Río Abajo State Forest, at 320–340 m. Other documented collections extend beyond that forest into additional northern Puerto Rican localities. Kew Plants of the World Online: Thelypteris abditaProctor (1985): New Species of Thelypteris from Puerto Rico, American Fern Journal 75:56–70
Botanical sources
- Kew Plants of the World Online: Thelypteris abdita
- Proctor (1985): New Species of Thelypteris from Puerto Rico, American Fern Journal 75:56–70
Reviewed 2026-10-11. Seasonal development varies with location and growing conditions.