Cremastosperma osicola Pirie & Chatrou

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

publication ID

http://dx.doi.org/10.3897/phytokeys.112.24897

persistent identifier

http://treatment.plazi.org/id/70725F65-0CF4-C766-2D5E-D1D2E90A6615

treatment provided by

PhytoKeys by Pensoft

scientific name

Cremastosperma osicola Pirie & Chatrou
status

sp. nov.

25. Cremastosperma osicola Pirie & Chatrou   sp. nov. Figs 23 View Figure 23 , 34 View Figure 34 , Map 2 View Map 2

Diagnosis.

Differs from C. megalophyllum   , C. pacificum   and C. yamayakatense   in the fully open bud development; from C. brevipes   , C. magdalenae   , C. novogranatense   , C. pacificum   and C. westrae   in the stipes being longer than the monocarps and (except C. magdalenae   ) in the usually much larger number of monocarps (20-40 as opposed to mostly fewer than 20); from C. westrae   and C. novogranatense   in the absence of indument on the fruits; from C. panamense   in the greater size of the fruits and the shape of the monocarps (ellipsoid, compared to more or less globose in C. panamense   ); and from all of the above except C. novograntense   in the much larger flowers.

Type.

COSTA RICA, Puntarenas: Cantón Osa, Distr. Sierpe, Los Mogos, Bahia de Chal, Entrada San Juan, 9 Sep 2011, Chatrou, L.W. et al. 707 (holotype: CR!; isotypes: K!, MO!, P!, U!).

Description.

Tree 3-7 m tall, 5-7 cm diam.; young twigs and petioles very sparsely covered with appressed whitish hairs to 0.2 mm long or glabrous. Leaves: petioles 7 –15(– 20) by 2-4 mm; lamina obovate to elliptic or narrowly so, 21-44 by 5-15 cm (index 2.6-3.4), chartaceous, green or brown above and below, veins darker below, glabrous above, very sparsely covered with appressed whitish hairs to 0.2 mm long, especially on veins or glabrous below, base acute or obtuse, apex acuminate (acumen 10-20 mm long), primary vein shallowly grooved near base, 1.5-2 mm wide at widest point, secondary veins 7-10, intersecondary veins 0-1, distance between from 10-13 mm at the base to 25-45 mm closer to the centre, angles with primary vein from 45-60° at the base to 70-80° closer to the centre, sometimes branching, forming distinct loops in apical half of leaf, smallest distance between loops and margin 2-3 mm, tertiary veins mostly percurrent. Inflorescence of single flowers solitary on leafless twigs or clustered in groups on brachyblasts on the main stem; peduncles 4 by 4 mm (in fruit); pedicels 18-23 by 3 mm at the base, 3-4 mm at the apex (in fruit), peduncles and pedicels glabrous; lower bract(s), upper bract and closed flower buds not seen, flowers (observed from photo: Fig. 21 o View Figure 21 ) cream in vivo; sepals not seen; petals indument not seen, outer petals elliptic, ca. 31 mm long, inner petals elliptic, ca. 27 by 9 mm; androecium ca. 7 mm diam., stamens not seen; gynoecium ca. 2 mm diam., carpels not seen. Monocarps 20-43, ellipsoid (broadly so in immature specimens), slightly asymmetrical, 11-17 by 11-12 mm, green maturing to yellowish, orange and purple in vivo, black in sicco, with a small excentric apicule, monocarps, stipes and receptacle glabrous; stipes 17-30 by 1.5-2 mm; fruiting receptacle ca. 14 mm diam. Seeds ellipsoid, reddish-brown, shallowly pitted, ca. 12 by 10 mm, raphe sunken, regular.

Distribution.

Costa Rica (Puntarenas, Osa peninsula).

Habitat and ecology.

Tropical wet forest. At elevations of 40-300 m. Fruiting: July and September.

Notes. The distribution of Cremastosperma osicola   in Costa Rica is the furthest north into Central America of any species of the genus. The species is most similar to C. pacificum   , from the Pacific coast of Colombia, from which it can be discerned with flowering material by the much larger flowers (outer petals ca. 31 mm compared to ca. 16 mm in C. pacificum   ) and with fruiting material by the length of the stipes exceeding that of the monocarps.

Preliminary conservation status.

Cremastosperma osicola   is known from a small number of populations within a region sufficiently small to qualify it as Endangered, but within a protected area (Golfo Dulce Forest Reserve). Near Threatened [NT] (Table 1).

Other specimens examined.

COSTA RICA. Puntarenas: Osa, Golfo Dulce Forest Reserve, 8°40'N, 83°31'W, 40-100 m a.s.l., 25 Sep 1991, R.Aguilar 467 (INB, MO); Cantón de Osa, 8°43'20"N, 83°26'40"W, 20-100 m a.s.l., 13 Nov 1995, R. Aguilar et al. 4371 (INB); Osa, Bahia Chal-La Palma road, 8°44'N, 83°26'W, 80 m a.s.l., 29 Nov 1998, Chatrou et al. 103 (U); Osa, Rancho Quemado, near Rincón, 8°42'N, 83°33'W, 300 m a.s.l., 11 Jan 1993, Gentry et al. 78657 (F, INB, MO); Osa, Parque Nacional Corcovado Cerro Brujo, 8°39'00"N, 83°35'50"W, 617 m a.s.l., 19 Jul 1990, G. Herrera et al. 3972 (INB); Osa, Parque Nacional Corcovado Sirena, 8°28'N, 83°35'W, 1 50 m a.s.l., 20 Jul 1989, Kernan 1224 (U); Osa, Golfo Dulce Forest Reserve, 8°42'N, 83°25'W, 100 m a.s.l., 2 Jul 1984, Schatz et al. 1002 (MO, U, WIS); Osa, Golfo Dulce Forest Reserve, 8°43'N, 83°26'W, 20 m a.s.l., 24 Jul 1995, Zamora & R. Aguilar 2312 (INB, U).