Guatteria rigida R.E.Fr.

Maas, P. J. M., Westra, L. Y. T., Guerrero, S. Arias, Lobão, A. Q., Scharf, U., Zamora, N. A. & Erkens, R. H. J., 2015, Confronting a morphological nightmare: revision of the Neotropical genus Guatteria (Annonaceae), Blumea 60 (1), pp. 1-219 : 145

135. Guatteria rigida R.E.Fr. — Fig. 54g , 65 ; Map 29

Guatteria rigida R.E.Fr. (1906) 8, t. 1, f. 1, 2; (1939) 482. — Type: Riedel 438 (holo S), Brazil, Mato Grosso do Sul, Rio Pardo, Aug. 1826 .

Tree or shrub 1–14 m tall, to c. 25 cm diam; young twigs rather densely covered with appressed hairs, very soon glabrous. Leaves: petiole 5–10 mm long, 1–3 mm diam; lamina elliptic to obovate or narrowly so, 7–18 by 3–7.5 cm (leaf index 1.8–3), coriaceous, not or sparsely verruculose, shiny, dark brown to greyish above, brown below, glabrous above, sparsely covered with appressed hairs, mainly along primary vein and margins below, base acute to attenuate, apex rounded, acute, emarginate, or shortly acuminate (acumen to c. 5 mm long), primary vein impressed to flat above, secondary veins distinct, 8–12 on either side of primary vein, raised above, smallest distance between (indistinct) loops and margin 3–4 mm, tertiary veins raised above, reticulate. Flowers solitary in axils of leaves; pedicels 15–30 mm long, 1–1.5 mm diam, fruiting pedicels to c. 3 mm diam, sparsely covered with appressed hairs, soon completely glabrous, articulated at 0.2–0.3 from the base, bracts 5–7, soon falling, not seen; flower buds broadly ovoid; sepals free, broadly ovate-triangular, 4–5 by 4–5 mm, ap- pressed, finally reflexed, outer side rather densely to sparsely covered with appressed hairs; petals yellowish green or cream in vivo, elliptic, 13–35 by 6–15 mm, outer side rather densely covered with appressed hairs, soon more or less glabrous; stamens 1–1.5 mm long, connective shield papillate. Monocarps 25–75, green to red in vivo, brown in sicco, ellipsoid or less often narrowly ellipsoid, 6–12 by 4–5 mm, sparsely covered with ap- pressed hairs, soon glabrous, apex apiculate (apiculum 0.5–1 mm long), wall 0.2–0.3 mm thick, stipes 3–8 by 1–2 mm. Seed ellipsoid, 7–10 by 4–5 mm, pale brown, pitted, raphe raised.

Distribution — Brazil (southern part of Amazonas, Goiás, Mato Grosso do Sul, Pará, Rondônia).

Habitat & Ecology — In dry or wet cerrado, sometimes in gallery forest, on sandy to rocky soil.At elevations of 100–1000 m. Flowering: March, June,August to December; fruiting: February, April to June, September, October.

Vernacular name — Brazil: Embireira-do-campo (Ratter et al. 1921).

Notes — Guatteria rigida is one of the few cerrado inhabiting species of Guatteria . It is quite characteristic by its thick leaves which mostly have a very prominent secondary and tertiary venation on the upper side. The apex of the lamina is quite variable, varying from obtuse, acute, emarginate to shortly acuminate. It shares several leaf features with another campo rupestris inhabiting species, namely G. rupestris . It differs from the latter by having a longer petiole (5–10 vs 2–4 mm long) and pedicels (15–30 vs 10–15 mm long), more monocarps (25–75 vs 10–15) and strongly pitted instead of smooth to slightly rugulose seeds.

Sasaki et al. ‘Parcela 2 540’ (K) from Brazil, Mato Grosso, Mun. Novo Mundo, growing in forests (‘floresta ombrófila densa submontana’) shares the leaf features with this species. It differs, however, by much longer monocarps of 14–15 by 5 mm and longer stipes of 12–14 mm long. The seeds appear to be smooth and are markedly different from the rugulose seeds found in G. rigida so far. This quite likely represents an as yet undscribed species perhaps allied to G. rigida , but more material is needed for further study.

Figures

Fig. 54 a. Guatteria oriximinae Maas & Westra. Fruit. – b. Guatteria pachycarpa Erkens & N.Zamora. Monocarp in cross section. – c, d. Guatteria paludosa R.E.Fr. c. Flowers;d. flower buds and bracts. – e. Guatteria procera R.E.Fr. Fruit. – f. Guatteria revoluta Maas & Westra. Rvolute leaf base, fruit and incomplete flower. – g. Guatteria rigida R.E.Fr. Fruit. – h. Guatteria ruboides Maas & Westra. Fruit (a: Cid et al. 9654, U; b: G. Herrera C. 5227, U; c, d: McDowell et al. 4815, U; e: Sperling et al. 6227, U; f: Vásquez & Jaramillo 8024, isotype U [sheet 2]; g: Anderson et al. 106, U; h: Vásquez & Jaramillo 8025, isotype AAU).

Fig. 65 Guatteria rigida R.E.Fr. Flowering branch (Pereira-Silva et al. 5770, U).