Annona caput-medusae Westra & H.Rainer, 2019

Maas, Paul J. M., Westra, Lubbert Y. Th., Chatrou, Lars W., Verspagen, Nadja, Rainer, Heimo, Zamora, Nelson A. & Erkens, Roy H. J., 2019, Twelve new and exciting Annonaceae from the Neotropics, PhytoKeys 126, pp. 25-69 : 27-28

Annona caput-medusae Westra & H.Rainer sp. nov. Figs 1 , 2

Diagnosis.

Annona caput-medusae resembles cauliflorous specimens of A. quinduensis Kunth (formerly Raimondia quinduensis ), but differs by the shorter pedicels (7-11 vs. 10-30 mm long) and smaller seeds (ca. 6 vs. 10-14 mm long).

Type.

COLOMBIA, Antioquia: Mun. Anorí, electric power plant, road to Aljibes , 7°19'61"N, 75°02'407"W, 350 m, 26 Mar 1996 (fl), Fonnegra et al. 5935 (holotype: HUA! [HUA104142]; isotype: MO! [MO1958355]) .

Description.

Tree 5-7 m tall, cauliflorous; young twigs rather densely covered with appressed brown hairs <0.5 mm long, soon glabrous. Leaves: petioles 16-18 by 2 mm; lamina narrowly elliptic, 28-30 by 9-12 cm (leaf index 2.5-3.1), membranous, greenish grey above in sicco, somewhat lighter so below, glabrous above except for the large veins sparsely covered with erect, brown hairs, sparsely covered with appressed hairs to glabrous below, base obtuse, extreme base very shortly attenuate, apex acuminate (acumen 10-15 mm long), primary vein impressed to flat above, secondary veins ca. 15, not loop-forming or loop-forming close to the apex (shortest distance between loops and margin ca. 2 mm), tertiary veins mostly percurrent, domatia present in axils of part of the secondary veins; plants androdioecious, probably: only bisexual flowers seen. Inflorescence borne on the stem on older branches, much-branched thyrsoids bearing many flowers in succession; pedicels 7-11 by 1-2 mm, gradually widening from base to flower, densely covered with appressed, brown hairs to 0.2 mm long; bracts triangular-ovate or broadly triangular-ovate, outer side densely covered with hairs 0.1-0.2 mm long, more or less persistent, upper bract 0.3-0.4 mm from base of pedicel; flower buds narrowly conical; sepals free or connate at the base, broadly ovate to triangular-ovate, ca. 1 mm long, appressed, later spreading to reflexed, apex acuminate, outer side densely covered with brown hairs; outer petals connate at the base, narrowly triangular, ca. 20 by 5 mm, outer side densely covered with brown hairs, inner petals ca. 0.4 the length of the outer ones, torus ca. 3 mm long, the lower third beset with stamens, the apical two-thirds beset with carpels; stamens ca. 150, ca. 1.5 mm long, anther oblong, ca. 1 mm long, no apical prolongation of connective; carpels 150-200. Fruit ellipsoid, ca. 6.5 by 3.5 cm, densely covered with brown hairs ca. 0.2 mm long in young stage, becoming glabrous, areoles not or weakly protruding, not apiculate. Seeds ca. 6 by 5 mm, brown.

Distribution.

Colombia (Antioquia, Caldas) (Fig. 3 ).

Habitat and ecology.

On industrial ground, in secondary forest. At elevations of 350-450 m. Flowering: March; fruiting: June.

Notes.

A domatium here is a small thin membrane in the axil spanning the distance between primary vein and secondary vein. It conforms to the Annona muricata type ( Van den Bos et al. 1989).

Annona caput-medusae clearly falls within a distinct group formerly known as the segregate genus Raimondia ( Safford 1913; Westra 1995), but (re-)united later with Annona ( Rainer 2007). When using Westra’s key A. caput-medusae comes closest to A. quinduensis Kunth which generally is not cauliflorous. Whereas A. quinduensis normally is found at higher elevations up to 2500 m, A. caput-medusae , as known from the scanty material collected thus far, occurs at elevations below 500 m. The flowers we examined appear to be bisexual. However, given the obvious similarity with other former Raimondia species, which are all androdioecious, staminate flowers might be expected in A. caput-medusae as well.

Etymology.

Caput (L) = head. Medusa, an ancient Greek goddess whose head was covered with snakes. Referring to the shape of the inflorescence.

Preliminary IUCN conservation status.

DD. This species is only known from two localities. Although the collections are not made near each other, more data are needed to determine the AOO and EOO. Also, the current population size and population trend of this species are unknown. Habitat loss because of forest cover loss is a possible threat for this species of Annona given its occurrence in fragmented forest areas. However, since proper data on the distribution of this taxon is lacking, we assessed it as Data Deficient.

Other specimen examined.

COLOMBIA. Caldas: Norcasia, Vereda Moscovita, quebrada Santa Bárbara, 5°34'N, 74°35'W, 450 m, 15 Jun 2001 (fr), Correa et al. 2307 (HUA).

Figures

Figure 1. Annona caput-medusae Westra & H. Rainer. Flowering specimen (Fonnegra et al. 5935, holotype HUA).

Figure 2. Annona caput-medusae Westra & H. Rainer. Fruiting specimen (Correa et al. 2307, HUA).

Figure 3. Distribution map of Annona caput-medusae, A. oleifolia, Guatteria attenuata, G. kamakusensis, G. pseudoferruginea, Klarobelia rocioae, and Xylopia longicaudata.