Pteridium esculentum (G.Forst.) Cockayne

Schwartsburd, Pedro B., Yañez, Agustina & Prado, Jefferson, 2018, Formal recognition of six subordinate taxa within the South American bracken fern, Pteridium esculentum (P. esculentum subsp. arachnoideum s. l. - Dennstaedtiaceae), based on morphology and geography, Phytotaxa 333 (1), pp. 22-40 : 33-36

3. Pteridium esculentum (G.Forst.) Cockayne subsp. gryphus Schwartsb. in Schwartsburd et al. (2017: xx)

Two varieties are recognized:

1. Veins abaxially with sericeous appearance, with lax, arachnoid hairs, 0.6–0.8 mm long............................................... var. gryphus

-. Veins abaxially glabrous or nearly glabrous............................................................................................................... var. harpianum

3a. Pteridium esculentum (G.Forst.) Cockayne subsp. gryphus Schwartsb. var. gryphus ( Figs. 2 , 3A–C , 4 )

Type:— VENEZUELA. Aragua: prope Coloniam Tovar, 1854–1855, A. Fendler 104 (holotype US!, isotypes G n.v., MO-4 sheets n.v., YU-3 sheets n.v., probably also in B, BM, K, and/or OXF, none seen).

Plants forming extensive thickets. Rhizomes long-creeping. Fronds to 3 m long; petioles proximally with epipetiolar roots; laminae proximally 3–4-pinnate-pinnatifid; pinnae and pinnules distally with free lobes between the segments; compound distal segments inequilateral, irregularly dissected, caudate at apex; simple distal segments linear, to 3(– 4) cm long; costae abaxially with reddish catenate hairs, 5–7-celled, 0.3–0.5 mm long, adaxially glabrous; costules abaxially with reddish catenate hairs, adaxially glabrous; veins abaxially sericeous, with lax, arachnoid hairs, 0.6–0.8 mm long, adaxially glabrous; laminar tissue between the veins abaxially with farinaceous appearance, not visible, totally covered by gnarled hairs, adaxially glabrous; laminar margins regularly transformed into pseudo-indusia; pseudo-indusia glabrous.

Distribution and ecology: — Colombia, Venezuela, Guyana, French Guiana, Ecuador (including Galapagos Isl.), Peru, Bolivia, and northwestern Argentina; possibly also in Mexico, Central America, Suriname, and northern Brazil; from sea level to ca. 3500 m (ca. 300–750 m in Galapagos) ( Figs. 2 , 4 ).

Specimens examined:— COLOMBIA. Antioquia: Road between Medellin and Rio Negro, 16 October 1947, F. A. Barkley & G. Gutiérrez 1434c ( LIL, CORD).— VENEZUELA. Amazonas: Atabapo , Sierra Parima , 2°42’N, 64°03’W, 1200 m, 13 February 1981, O. Huber 5980 (US). Bolívar: Chimantá Massif, 1700 m, 21 May 1953, J. A. Steyermark 75507 ( US). Distrito Capital: Caracas, June 1917, H. M. Curran & M. Haman 1111 ( GH n.v., US-2 sheets) ; Caracas and vicinity, 10°30’N, 3000–3500 ft, 2 January 1921, L. H. Bailey & E. Z. Bailey 650 ( US) ; Cerros del Avila , 1600 m, 7 October 1921, E. Pittier 41 ( US) ; Los Venados, south side of Pico Avila, just north of Caracas , 1300–1500 m, 12 September 1961, R. M. Tryon & A. F. Tryon 5720 (US). Monagas : SW of Caripe, 1100 m, 26 April 1967, R. A. Pursell et al. 8775 ( US).— GUYANA. Demerara-Superior : Malali , Demerara river, 5°35’N, 30 October–5 November 1922, J. S. de la Cruz 2658 ( F n.v., G n.v., NY n.v., US). [Potaro-Siparuni]: Tumatumari, 18 June–8 July 1921, H. A. Gleason 423 (US).— FRENCH GUIANA. Cayenne: Perrouquets, région littorale, 5°15’30”N, 52°47’36”W, 8 m, 11 May 2007, J. J. de Granville & O. Tostain 17423 (US).— ECUADOR. Chimborazo: Cañon of the Río Chanchan , 5000–6500 ft, 19–28 May 1945, W. H. Camp E-3357 (US). Pichincha: road along Santo Domingo-Tandápi, 1500 m, 10 January 1967, B. Sparre 13901 ( US) ; San José de Minas, 1600–2000 m, A. Mille 140 ( US). Zamora-Chinchipe : 32 km from Zamora , 0°24’N, 78°48’W, 1925 m, 19 March 1995, A. Ortiz et al. 497 ( US). Galapagos Islands : Abingdon Island [Pinta], south side of the island, above 1600 ft, 19 September 1905 –1906, A. Stewart 992 ( US) ; Chatham Island [San Cristóbal], Wreck Bay 1000–2100 ft, 23 February 1905 –1906, A. Stewart 995 ( US) ; Isla Santa Cruz, trail to Mt. Crocker [Crocket], 500–560 m, 6 February 1964, I. L. Wiggins 18616 ( US) ; Narborough Island [Fernandina], SW slope, 750 m, 4 February 1964, D. Cavagnero 10 (US).— PERU. Ayacucho: Estrella, between Huanta and Río Apurimac, 500 m, 8–14 May 1929, Killip & Smith 23095 (US). Cajamarca : Tabaconas , 5°20’S, 79°18’W, 1900 m, 11 Jun 1947, Fosberg 27786 ( US). Cusco: Pillahuata, Cerro de Cusilluyoc , 2200–2400 m, 3–6 May 1925, Pennell 13936 (US) ; San Miguel: Urubamba Valley, 1800 m, 28 May 1915, Cook & Gilbert 953a ( US). Huánuco : Chinchao , 16 Aug 1940, Asplund 13146 ( US) ; Pampayaco , 20 Jan 1927, Kanehira 169 ( US) ; Huánuco , 2300 m, 12 Sep 1956, Tryon & Tryon 5224 ( BM n.v., F n.v., MO n.v., U n.v., US, USM n.v.) ; Chinchao to Puente Durand , 2000 m, 12 Dec 1953, Coronado 92 ( GH n.v., US-on 4 sheets) ; Playapampa , 9000 ft, 16–24 Jun 1923, Macbride 4507 (US). Junín: Mito, 9000 ft, 8–22 Jul 1922, Macbride & Featherstone 1671 ( US). La Libertad: Trujillo, Cerro Campana, 800 m, 19 Apr 1976, Sagástegui & Cabanillas 8352 ( MO n.v., US).— BOLIVIA. Cochabamba: Sacaba, bosque de Incachaca, 1 September 1921, J. Steinbach 5740 ( LIL). La Paz: Prov. Bautista Saavedra, Charanzani-Tal, 2750 m, 8 November 1979, T. Feuerer 6731e (US) ; Hacienda Simaco sobre el camino a Tipuani , 1400 m, January 1920, O. Buchtien 5271 ( US) ; Prov. Murillo, 1 km W of Estancia Islani Bajo and Planta Hidroeléctrica Jarca, 18 June 1998, M. Nee & L. Bohs 49774 ( MO n.v., NY n.v., SP).— ARGENTINA. Córdoba: Depto. San Javier , Traslasierra , Uritorco , 30 November 2012, M. C. Luján 290 ( CORD) ; Sierra de Achala, 28 March 1986, F. Kuntz 3948 ( SI). Jujuy: Dept. Capital, Mina 9 de Octubre, 7 April 1971, F. Vervoorst 4555 ( SI). Salta: Dept. Santa Victoria, Baritú National Park , 28 January 1985, Brown 2010 ( SI) .

Notes:— Pteridium esculentum subsp. gryphus is a well-defined and widespread subspecies, along with P. esculentum subsp. arachnoideum and P. esculentum subsp. campestre , with its own distribution preference (western and northern South America) ( Figs. 2 , 4 ). Apparently, this is the only subspecies of P. esculentum that occurs west of the Andes and on the Galapagos Islands. Pteridium esculentum subsp. gryphus var. gryphus is characterized by free lobes between the ultimate segments, inequilateral, irregularly dissected compound distal segments, which are caudate at apex, simple distal segments to 3(–4) cm long, lax, arachnoid hairs abaxially on veins, giving a sericeous appearance, and gnarled hairs fully covering the laminar tissue between the veins, abaxially, giving it a farinaceous appearance ( Figs. 3A–C ).

Among the South American morphotypes, Pteridium esculentum subsp. gryphus var. gryphus is the one most similar to the Australasian P. esculentum subsp. esculentum , and also closest geographically ( Figs. 2 , 4 ).

3b. Pteridium esculentum (G.Forst.) Cockayne subsp. gryphus Schwartsb. var. harpianum Schwartsb. & A.Yanez , var. nov. ( Figs. 3D–F , 4 )

Type:—FRENCH GUIANA. St. Laurent du Maroni: Mont Galbao, 3°35’N, 53°20’W, 650 m, 24 January 1986, J.J. de Granville et al. 8979 (holotype US!, isotypes CAY n.v., P n.v., probably also in B, BM, MG, NY, U, and Z, none seen).

Veins abaxially glabrous or nearly glabrous, laminar tissue between the veins abaxially with farinaceous appearance, covered by gnarled hairs.

Plants probably forming extensive thickets. Rhizomes long-creeping. Fronds to 2.5 m long; petioles proximally with epipetiolar roots; laminae proximally 3-pinnate-pinnatifid; pinnae and pinnules distally with free lobes between the segments; compound distal segments inequilateral, irregularly dissected, caudate at apex; simple distal segments linear, to 3 cm long; costae abaxially with reddish catenate hairs, 5–7-celled, 0.3–0.5 mm long, or glabrescent, adaxially glabrous; costules abaxially with sparse reddish catenate hairs, or glabrescent, adaxially glabrous; veins abaxially glabrescent to glabrous, adaxially glabrous; laminar tissue between the veins abaxially with farinaceous appearance, not visible, totally covered by gnarled hairs, adaxially glabrous; laminar margins regularly transformed into pseudo-indusia; pseudo-indusia glabrous.

Distribution and ecology: — Guyana, Suriname, French Guiana, and northern Brazil; from 300 m to 650 m ( Fig. 4 ).

Etymology:— The varietal epithet is derived from the harpy eagle or royal-hawk ( Harpia harpyja Linnaeus, 1758 ), the biggest bird of prey in central South America. Due to the pinnae parallel to the ground, the fronds of most Pteridium species present an “eagle-like” appearance.

Specimens examined:— GUYANA. Cuyuni-Mazaruni: Penal settlement, 3–9 December 1919, A. S. Hitchcock 17031 (US).— SURINAME. [Sipaliwini?]: Tumno Humno , 320 m, 8 September 1972, J. J. de Granville 1511 (US) ; [Paramaribo?]: Ono bissi, fluv. Coppename, 4 March 1915, “ B. W. ” 1121 (US-2019769).— BRAZIL. Amazonas: Manaus, 2°19’S, 60°05’W, 10 February 1992, M. Nee 42424 (US) ; Manaus, Reserva Florestal Ducke, 2°53’S, 59°58’W, 20 March 1995, J. Prado et al. 631 ( INPA, SP). Presidente Figueiredo, Hotel Iracema Falls , 24 August 2012, R. W. Barreto 1623 (VIC-on 2 sheets). Amapá: 5 km l’este de Porto Grande, 17 October 1979, D. F. Austin et al. 7063 ( US) .

Notes:— Pteridium esculentum subsp. gryphus var. harpianum is a local, glabrous form of P. esculentum subsp. gryphus from the Guianas region ( Fig. 4 ). Both are easily differentiated from each other: while var. harpianum has glabrescent to glabrous veins abaxially ( Figs. 3D–F ), var. gryphus has sericeous veins, with conspicuous, lax, arachnoid hairs ( Figs. 3A–C ).

Figures

FIGURE 2. Distribution of Pteridium esculentum subsp. arachnoideum (red circles), P. esculentum subsp. campestre (green circles), and P. esculentum subsp. gryphus (blue circles) in South America.

FIGURE 3. A–C. Pteridium esculentum subsp. gryphus var. gryphus: A. pinnule (Gleason 423), B. segment, abaxially (Gleason 423), C. segment, cross section, abaxial side up, showing sericeous veins, with lax, arachnoid hairs, and laminar tissue between the veins with farinaceous appearance, fully covered by gnarled hairs (Gleason 423), D–F. Pteridium esculentum subsp. gryphus var. harpianum: D. pinnule (“B.W.” 1121 [US-2019769]), E. segment, abaxially (Barreto 1623), F. segment, cross section, abaxial side up, showing veins abaxially nearly glabrous, and laminar tissue between the veins with farinaceous appearance, fully covered by gnarled hairs (Barreto 1623). Drawn by R. Pinto.

FIGURE 4. Distribution of Pteridium esculentum subsp. gryphus var. gryphus (blue circles) and P. esculentum subsp. gryphus var. harpianum (yellow circles) in South America.