Christella hispidula (Decne.) Holttum,

Castro-Aguiar, Pedro Henrique, Fernandes, Rozijane Santos & Zappi, Daniela Cristina, 2025, Ferns of the Parque Nacional das Nascentes do Rio Parnaíba Brazilian Cerrado, Rodriguesia (e 00612024) 76, pp. 1-24 : 19

15.2. Christella hispidula (Decne.) Holttum, Kew Bull. 31(2): 312 (1976). Fig. 5 c-d

Plants terrestrial. Stem decumbent to short-creeping, with lanceolate scales, 4.5–7 mm long, dark brown, pilose. Fronds 76–133.5 cm long, monomorphic, pinnatisect; petiole 33.5–54 cm long, paleaceous to pale brown, sulcate adaxially, with hairs on both sides; rachis sulcate adaxially, with acicular hairs on both sides; laminae 42.5–84.5 × 18–42 cm, pinnate-pinnatifid, lanceolate, base with 1–2(–3) pairs of reduced pinnae; pinnae median 10.8–20.6 × 1.4–2.6 cm, 23–28 pairs, linear-lanceolate, chartaceous, both sides with acicular hairs on the costae, veins, and laminar tissue between the veins, margins entire, base truncate, apex acute to rounded; basal veins of adjacent segments joining well below the sinus, rarely at the sinus. Sori rounded, median, indusia rounded, with acicular hairs.

Examined material: Alto ParnaÍba, PNNRP, Povoado Curupá, 09°53’05’’S, 45°53’20’’W, 19.IV.2022, P. H. C. Aguiar et al. 12 ( CCAA, UB) .

Christella hispidula is a pantropical species of wide distribution, occurring from the Southeast of the United States to Argentina, also occurring in the Caribbean region, in tropical and subtropical Africa ( Smith & Kessler 2017c; Fawcett & Smith 2021). In Brazil, it is recorded for the Amazon, Cerrado, and Atlantic Rainforest biomes ( Salino et al. 2023). In the study area, it was found in the margin and interior of the vereda, in shaded, dry banks.

Characterized by the 1-pinnate-pinnatisect, with acicular hairs on both sides, costae abaxially with hairs of unequal length, reaching until 1mm in length; the basal veins united almost always well below the sinus, forming an excurrent vein that leads to the sinus, the indusia only bear acicular hairs. Christella hispidula can also be confused with C. dentata (Forssk.) Brownsey & Jermy , however, the latter differs due to the generally brown petioles and rachis, and by the costae with predominantly short and uniform hairs abaxially, the majority of 0.1 to 0.2 mm in length, while C. hispidula has paleaceous pale-brown petioles and rachis and abaxial hairs over 0.3 mm long, sometimes reaching more than 0.5 mm. ( Smith & Kessler 2017c).

Figures

Figure 5 – a. Cheilanthes pohliana – habit. b. Pityrogramma calomelanos – habit. c-d. Christella hispidula – c. habit; d. sori on the abaxial surface. e-f. Meniscium arborescens – e. habit; f. sori on the abaxial surface. g. Meniscium delicatum – habit. h-i. Meniscium maxonianum – h. habit; i. sori on the abaxial surface. (a. P.H. Castro-Aguiar et al. 283; b. P.H. Castro-Aguiar et al. 244; c-d. P.H.C. Aguiar et al. 12; e-f. P.H.C. Aguiar et al. 6; g. P.H. Castro-Aguiar et al. 97; h-i. P.H. Castro-Aguiar et al. 166).