Sapranthus chiapensis Standl. ex G.E.Schatz, 2018

Schatz, G. E., Maas, P. J. M., Kamer, H. Maas-van de, Westra, L. Y. T. & Wieringa, J. J., 2018, Revision of the Neotropical genus Sapranthus (Annonaceae), Blumea 63 (1), pp. 54-66 : 57

2. Sapranthus chiapensis Standl. ex G.E.Schatz , sp. nov. — Fig 1a ; Map 1

Sapranthus chiapensis is recognized by its flowers borne one at a time on perennial short shoots back from the leaves on older wood (ramiflorous), and its monocarps bearing plate-like, lamellar, lacerate excrescences to 10 mm tall. — Type: Matuda 16420 (holo MEXU [ MEXU00013176 ]; iso F 2 sheets, K, MEXU, MICH, NY), Mexico, Chiapas, Jamaica, Escuintla , 24 Sept. 1946 .

Shrub 4–5 m tall, diam not recorded; young twigs and petiole densely covered with mainly erect, pale golden brown hairs to c. 0.5 mm long. Leaves: petiole 4–11 mm long, c. 2 mm diam; lamina elliptic to elliptic-obovate, 5–20 by 3–8 cm, shiny and sparsely covered with appressed hairs above, densely covered with erect, white hairs below, base slightly asymmetric, acute to obtuse, apex acute to shortly acuminate (acumen to c. 5 mm long), venation weakly brochidodromous, primary vein slightly impressed above, secondary veins 11–13 on either side of pri- mary vein, raised above, tertiary veins raised above, percurrent. Inflorescence and flower indument: pedicels and outer side of bracts, sepals, and petals sparsely to rather densely covered with appressed, white hairs. Flowers borne one at a time on perennial short shoots (rhipidia) on older wood back from the leaves, i.e., ramiflorous, the short shoots to c. 2 cm long; pedi- cels 7–10 mm long, c. 2 mm diam, fruiting pedicels to c. 18 mm long and c. 8 mm diam, densely covered with appressed hairs 0.4–0.6 mm long, bearing at its base a broadly ovate to orbicular bract, 6–7 by 4–6 mm, base obtuse to rounded, apex acute to obtuse, with evident venation; sepals broadly ovate to ovate, 12–13 by 7–11 mm, reflexed at anthesis, base truncate to concave and decurrent along the pedicel, apex acute, with evident venation; petals membranous, dark purple, with 5–7 longitudinal veins interconnected by faint cross veins, the former prominently raised on the outside, outer petals narrowly elliptic, 28–36 by 10–16 mm, concave, base cuneate, the point of at- tachment c. 4 mm broad, apex acute with a rounded tip, inner petals narrowly elliptic-oblong, 28–31 by 10–13 mm, base tapering abruptly and geniculate, forming a claw c. 3 mm long, c. 3 mm broad at the point of attachment, c. 5 mm wide at the point of the bend, with a corrugated food body present just above the claw inside consisting of c. 6 ridges separated by furrows, c. 4 mm long, c. 6 mm broad at its upper margin. Monocarps c. 6 (to potentially 20), greyish green, ellipsoid-oblongoid to obovoid, 10–63 by 23–45 mm, densely to sparsely covered with appressed hairs 0.3–0.4 mm long, bearing anastomosing, plate-like, lamellar, lacerate excrescences to c. 10 mm high, wall c. 0.5 mm thick, stipes 0–7 mm long. Seeds 4 or 5, in one or two rows, spherical wedge-shaped, 18–22 by 9–16 mm, smooth, light tan.

Distribution — Mexico (Chiapas).

Habitat & Ecology — In tropical dry deciduous forest. At elevations of c. 200 m.

Vernacular names — Mexico: Haste, Pataste de Mico (Chia- pas, Matuda 16420, 16466).

Other specimen examined. MEXICO, Chiapas, Nueve Libertad,Escuintla,

Matuda 16466 ( paratypes BR, F, MEXU 2 sheets, MICH) .

Notes — Standley annotated the only two known collections of this species, both collected by Matuda, as Sapranthus chiapensis sp. nov. However, the name was never published, and we here adopt his epithet for this narrow Mexican endemic. With respect to leaf indument and floral characters, this distinctive species differs only slightly from the widespread Pacific dry forest S. violaceus . However, both the inflorescence structure, and the surface of the monocarps are unique within the genus. With the exception of S. palanga , whose flowers are borne at condensed flowering nodes primarily along the main trunk (trunciflory), all other Sapranthus species bear solitary, terminal flowers, which nonetheless appear leaf-opposed by extension of the renewal shoot. In contrast, S. chiapensis produces flowers, one at a time, on distinct short-shoots (rhipidia), these located on somewhat older branches just back of the leaves (ramiflory), a condition thus intermediate between S. palanga and all other Sapranthus species. At first glance, the surface sculpturing of the monocarps might appear to be an aberration, the possible result of disease. However, both collections exhibit identical plate-like excrescences. Although unique within Sapranthus , such monocarp surface sculpturing also occurs in several other Annonaceae including Stenanona costaricensis R.E.Fr. from Costa Rica and Nicaragua, as well as West African Piptostigma multinervium Engl. & Diels and Monocarpia borneensis Mols & Kessler in SE Asia.

Figures

Map 1 Distribution of Sapranthus campechianus (Kunth) Standl. (t), S. chiapensis Standl. ex G.E.Schatz (▲), S. hirsutus van Rooden ex G.E.Schatz (■), and S. viridiflorus G.E. Schatz (●).

Fig. 1 a. Sapranthus chiapensis Standl. ex G.E.Schatz. Vegetative branch and fruit. — b. Sapranthus hirsutus van Rooden ex G.E.Schatz. Flowering branch (a: Matuda 16420, type, MEXU; b: Williams & Molina R. 18053, type, MO).