Cremastosperma stenophyllum Pirie

Pirie, Michael D., Chatrou, Lars W. & Maas, Paul J. M., 2018, A taxonomic revision of the Neotropical genus Cremastosperma (Annonaceae), including five new species, PhytoKeys 112, pp. 1-141 : 1

31. Cremastosperma stenophyllum Pirie Fig. 41 , Map 2

Cremastosperma stenophyllum Pirie, Blumea 50: 56, f. 8. 2005.

Type.

ECUADOR, Pichincha: ‘Tinalandia’, km 112 on the road to Santo Domingo de los Colorados from Quito, 500-1000 m a.s.l., 15 Jan 1984, Knapp, S. & Mallet, J. 6159 (holotype: QCNE [QCNE4139]; isotype: QCA! [QCA5625]).

Description.

Tree 5-10 m tall, up to 20 cm diam.; young twigs and petioles rather densely covered with appressed golden hairs to 0.2 mm long. Leaves: petioles 5-12 by 2-2.5 mm; lamina narrowly elliptic to elliptic, 25-33 by 6.5-11.5 cm (index 2.9-4.3), chartaceous, greyish-green above, green below, sparsely covered with appressed yellowish-white hairs to 0.2 mm long below and on veins above, base acute, apex acuminate (acumen 20-25 mm long), primary vein 1-1.5 mm wide at widest point, verrucose, secondary veins 8-10, intersecondary veins occasional, distance between from 5 mm at the base to 50 mm closer to the apex, angles with primary vein from 45-55° at the base to 70-80° closer to the apex, not branching, not forming loops, tertiary veins with some reticulation. Inflorescence of single flowers on leafy twigs or on brachyblasts on thicker twigs or branches; peduncle 1.5-3 by ca. 1 mm (in flower), ca. 6 by ca. 2 mm (in fruit); pedicels 45-55 by ca. 1 mm (in flower), ca. 62 by ca. 1.5 mm (in fruit), peduncles and pedicels and outer side of bracts (densely), sepals (densely) and petals (sparsely to rather densely) covered with appressed yellowish-white hairs to 0.2 mm long; 2 lower bracts, deltate, ca. 1 mm long, obtuse; upper bract attached on basal half of pedicel, ovate, ca. 1.5 by 0.8 mm, acute; closed flower buds not seen; flowers green, maturing to yellow in vivo, light brown with dark brown patches at the base of the petals in sicco; sepals deltate, 2 mm long, obtuse; outer petals elliptic, ca. 18 by 8 mm, inner petals elliptic, ca. 18 mm long (diam. unknown); androecium and gynoecium not seen. Monocarps ca. 4, ellipsoid, slightly asymmetrical, ca. 25 by ca. 12 mm, black in sicco, with a strongly excentric apicule; stipes ca. 8 by ca. 2.5 mm; fruiting receptacle ca. 4 mm diam.; monocarps, stipes and receptacle with occasional appressed white hairs <0.1 mm long. Seeds not seen.

Distribution.

Ecuador ( Bolívar, Pichincha).

Habitat and ecology.

Secondary vegetation with primary elements. At elevations of 500-1200 m. Flowering: January; fruiting: not recorded.

Vernacular names.

Ecuador: Molinillo (Acosta Solís 6429).

Notes.

Only three collections of Cremastosperma stenophyllum , one of which is sterile, have been observed by the authors. However, these are consistently distinct from all other species of the genus. C. stenophyllum can be distinguished even when sterile by the narrowly (or nearly so) elliptic long acuminate leaves. The flowers and fruits resemble those of C. awaense Pirie, but both the pedicel and leaf acumen are longer and C. stenophyllum also lacks the distinctive pattern of indument on the petals of C. awaense : the hairs are instead evenly distributed on the outer surface.

Conservation status.

We have seen one further specimen since Cremastosperma stenophyllum was described, bringing the total to three, representing highly fragmented populations, none of which is in a protected area. Endangered [EN] (Table 1 ).

Other specimens examined.

ECUADOR. Bolívar: Valle de Limón, 800-1200 m a.s.l., 16 Oct 1943, Acosta Solís 6429 (F); Esmeraldas: Quinindé Cantón, Cristobal Colón, 0°27'N, 79°09'W, 700 m a.s.l., 20 Oct 2008, Palacios 16384 (ECUAMZ, MO, QCNE).

Figures

Map 2. Distribution of Cremastosperma alticola Pirie & Chatrou, C. antioquense Pirie, C. chococola Pirie, C. dolichopodum Pirie & Maas, C. longipes Pirie, C. novogranatense R. E. Fr., C. osicola Pirie & Chatrou, C. panamense Maas and C. stenophyllum Pirie

Figure 41. Cremastosperma stenophyllum Pirie. a flower and leaf (Knapp & Mallet 6159).