Pteridium esculentum subsp. arachnoideum

4. Pteridium esculentum subsp. arachnoideum View in CoL × Pteridium esculentum subsp. campestre ( Figs. 5F–H View FIGURE 5 , 7 View FIGURE 7 )

Plants probably forming small thickets. Rhizomes long-creeping. Fronds to 3 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 equilateral, regularly dissected, caudate at apex; simple distal segments linear, to 2.5(–3) 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 strigose, with stiff, acicular hairs, 0.2–0.3 mm long, adaxially glabro us; 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: — Venezuela, Guyana, and Brazil; from 150 m to 1950 m ( Fig. 7 View FIGURE 7 ).

Specimens examined:— VENEZUELA. Amazonas: Río Negro , 1°57’N, 67°00’W, 150 m, 22 February 1989, G. Aymard et al. 7376 (US) GoogleMaps ; Atabapo, 04°34’N, 65°31’W, 590 m, February 1992, A. Chaviel 189 (US). Bolivar: Meseta del Jaua, Cerro Jaua, 4°48’50”N, 64°34’10”W, 1850–1920 m, 4 March 1974, J. A. Steyermark et al. 109770 ( US).— GUYANA. Cuyuni-Mazaruni: Bartica-Potaro Road , 6 miles south of Bartica , 9 April 1956, J. R. Ramsammy 28 (US).— BRAZIL. Pernambuco: Timbaúba , Eng. Xixá, 22 May 1992, I. C. L. Barros et al. s.n. (PEUFR-21053) GoogleMaps .

Bahia: Chapada Diamantina, Morro do Chapéu, 11°35’28”S, 41°12’27”W, 15 March 2008, M. L. Guedes et al. 14217 ( ALCB, VIC-frag.) GoogleMaps ; Morro do Chapéu, Marrão, Mata de Grotão , 11°35’S, 41°12’W, 5 May 2007, J. L. Ferreira & F. R. Nonato 81 (HUEFS-on 2 sheets) GoogleMaps ; Mucugê, Unidade de Manejo Sustentável Piabinha , 12°59’33”S, 41°20’30”W, 930 m, 12 January 1997, A. S. Conceição et al., UMS 206 View Materials ( HRB) GoogleMaps .

Notes:— This putative hybrid between Pteridium esculentum subsp. arachnoideum and P. esculentum subsp. campestre occurs in places of sympatry ( Fig. 7 View FIGURE 7 ) and has intermediate morphology between the parents. It has the unique laminar indument of subsp. campestre ( i.e., veins abaxially strigose, with stiff, acicular hairs, laminar tissue between veins fully covered with gnarled hairs), and the laminar architecture similar to subsp. arachnoideum : free lobes between the ultimate segments, compound distal segments with caudate apex, and simple distal segments to 2.5(–3) cm long ( Figs. 5F–H View FIGURE 5 ; see also Figs. 1A–F View FIGURE 1 ).