Cremastosperma yamayakatense 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

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Cremastosperma yamayakatense Pirie


34. Cremastosperma yamayakatense Pirie   Figs 37 View Figure 37 , 44 View Figure 44 , Map 8 View Map 8

Cremastosperma yamayakatense   Pirie, Arnaldoa 11: 10, f. 2, 6-8. 2004.


PERU, Amazonas: Bagua, Distr. Imaza, community Yamayakat, trail to Putuim, 22 Nov 2003, Pirie, M.D. et al. 57 (holotype: U! [U0121237]; isotypes: CUZ!, HAO!, HUT!, K! [K000580473], MO! [MO-1459049], NY! [NY006890], USM!).


Tree 1.5-8 (-20) m tall; young twigs and petioles glabrous. Leaves: petioles 5-10 by 1-5 mm; lamina narrowly elliptic to elliptic, 11-24 (-38) by 3.5-8 (-13) cm (index 2.4-3.4), chartaceous, olive-grey green above, light brown below, glabrous on both sides, base acute, apex acuminate (acumen 10-25 mm long), primary vein grooved in basal quarter to third, 1-4 mm wide at widest point, secondary veins 8-10 (-14), intersecondary veins occasional, distance between from 5-10 mm at the base to 10-30 mm closer to the apex, angles with primary vein from 70-80°, the angle thereafter decreasing and subsequently increasing again towards the leaf margin, not branching, forming distinct loops, smallest distance between loops and margin 2-6 mm, tertiary veins largely percurrent with some reticulation. Inflorescences of single, successively produced, flowers, axillary on leafy branches and on older (leafless) branches (then on brachyblasts); peduncles ca. 1 by 1 mm (in flower), 1-3 by 2-2.5 mm (in fruit), sparsely covered with golden hairs ca. 0.1 mm long; pedicels 5-7 by ca. 1.5 mm at the base (in flower), 8 –15(– 20) by 2-2.5 mm at the base to 4 mm at the apex (in fruit), glabrous; single lower bract, deltate, 1-2 by 1-2 mm, acute, mostly soon falling off in fruit, rather densely covered with golden hairs 0.1 mm long; upper bract inserted within basal half of pedicel, deltate, 1-2 by 1-2 mm, acute, glabrous; closed flower buds depressed ovoid, remaining closed in development; flowers green maturing to yellow in vivo, black in sicco, sepals and petals glabrous; sepals basally connate, deltate, appressed, ca. 3 by 3 mm, rounded, soon falling off, rarely persistent; outer petals ovate, 10-15 by 8-12 mm, inner petals elliptic, ca. 12 by 6 mm; androecium 6-7 mm diam., stamens ca. 1 mm long, connective appendage ca. 0.5 mm wide; gynoecium ca. 3 mm diam., carpels length and indument unknown. Monocarps 10-22, green maturing through red to black in vivo, black in sicco, ellipsoid, slightly asymmetrical, 12-14 by 7-8 mm, with an excentric apicule; stipes green maturing to red in vivo, 11-12 by ca. 1.5 mm increasing to 3 mm when ripe; fruiting receptacle 5-10 mm diam., monocarps and stipes glabrous or sparsely covered with golden hairs <0.1 mm long, receptacle glabrous. Seeds ellipsoid, reddish-brown with small black pits surrounded by a slightly raised rim, 9-13 by 6-7 mm, raphe sunken, regular.


Peru (Amazonas), watershed of the upper Río Marañon.

Habitat and ecology.

Primary and secondary forest. At elevations of 200-1000 m. Flowering: November, January-March; fruiting: throughout the year except December and April.

Vernacular names.

Peru: ciwánim yaáu (Kayap 33), Cuicui yais (Berlin 1588), Washi yais (Huambisa; Tunqui 573), Yais (R. Vásquez et al. 24797).


Cremastosperma yamayakatense   resembles two other species of Cremastosperma   ; C. gracilipes   , which has been collected in the departments of Napo and Pastaza in Ecuador, Loreto in Peru and in adjacent Colombia and C. cenepense   , from the Cenepa region of Amazonas, Peru, with which its distribution therefore overlaps. The most important differences between C. yamayakatense   and C. gracilipes   are in the flowers. C. gracilipes   is characterised by flower buds which open during development and which bear indument on all parts. In contrast, the flower buds of C. yamayakatense   bear virtually no indument and appear to remain closed throughout development, the petals only opening slightly when the flowers are mature. Additionally, the flowers of C. gracilipes   are borne on longer, more slender pedicels than those of C. yamayakatense   . C. yamayakatense   differs from C. cenepense   in the shape of the leaf base (acute in C. yamayakatense   , cordate to subcordate in C. cenepense   ) and the length of the stipes (longer than the monocarps in C. yamayakatense   , shorter than the monocarps in C. cenepense   ). The lack of flowering material of C. cenepense   makes further distinction currently impossible.

Flowering and fruiting specimens of C. yamayakatense   of around 1.5 m tall were observed in the province of Bagua, though specimens collected both in this area and particularly those collected further north into the province of Condorcanqui, in the area of the Río Cenepa, have been recorded as reaching heights of 6-8 m and in one case 20 m tall. Differences between collections from these two regions have been observed: the leaves of Condorcanqui specimens are generally larger and the fruits have a slight indument whereas those of the Bagua collections are glabrous. In the absence of floral material from the Cenepa region, it is assumed that these specimens do represent the same species due to the short pedicel, leaf base shape (which excludes the possibility of their representing specimens of C. cenepense   ) and leaf venation.

Preliminary conservation status.

Cremastosperma yamayakatense   is restricted in its extent and not found within protected areas. Vulnerable [VU] (Table 1).

Selected specimens examined.

PERU. Amazonas: Río Cenepa, Huampami, 4°30'S, 78°30'W, 200-250 m a.s.l., 7 Aug 1978, Ancuash 1324 (U); Bagua, Imaza, 4°45'S, 78°30'W, 750-1000 m a.s.l., 22 Sep 1997, Chávez 70 (U); Bagua, Yamayakat, 4°55'S, 78°19'W, Jan 1995, Hodges & Gorham 111 (HUT); Bagua, Yamayakat, trail to Putuim, 5°02'55"S, 78°21'06"W, 356-420 m a.s.l., 23 Nov 2003, Pirie et al. 80 (U, USM); Río Santiago valley, Quebrada Caterpiza, 3°50'S, 77°40'W, 200 m a.s.l., 12 Jan 1980, Tunqui 573 (MO); Bagua, Aramango, 5°29'54"S, 78°20'00"W, 1650 m a.s.l., 17 Dec 2001, Vásquez et al. 27434 (U).

Dubious species

Guatteria socialis   J.F.Macbr., Publ. Field Columbian Mus., Bot. Ser. 4: 171. 1929.

Type. PERU, Junín: Chanchamayo Valley, 1500 m a.s.l., Oct 1924-1927., C. Schunke 395 (holotype: F, isotype: S! [S08-16252]).

The type specimen of G. socialis   represents a species of Cremastosperma   , but to which species it might belong is not clear.

Excluded species

Cremastosperma anomalum   R.E.Fr., Kongl. Svenska Vetenskapsakad. Handl. 24: 4, pl. 1c-d. 1948.

Type. COLOMBIA, Chocó: Bahia Solano, near Ciudad Mutis, along Quebrada Jella, 0-75 m a.s.l., 21-23 Feb 1939, Killip, E.P. & Garcia, H. 33600 (holotype: S; isotypes: COL, UC, US).

Klarobelia   anomala (R.E.Fr.) Chatrou (1998) 123, f. 2.

Cremastosperma guianense   R.E.Fr., Acta Horti Bergiani 12: 205. 1934.

Type. GUYANA, Apoteri: Rupununi River, 21 Jul 1931, Forest Dep. Brit. Guiana 2093 = Davis, T.A.W. 102 (holotype: K).

Pseudoxandra   lucida   R.E.Fr., Acta Horti Bergiani 12: 230, f. 3a-e. 1937:

Cremastosperma polyphlebum   (Diels) R.E.Fr., Acta Horti Bergiani 10: 331. 1931.

Type. BRAZIL, Acre: Rio Jurua-Mirim, Aug 1901, Ule, E. 5628 (holotype: B; isotypes: F, G, K! [K000485701], MG, S! [S-R-7018]).

Pseudoxandra polyphleba   (Diels) R.E.Fr., Acta Horti Bergiani 12: 230. 1937.

Cremastosperma williamsii   R.E.Fr., Acta Horti Bergiani 12: 206. 1934.

Type. PERU, Loreto: Yurimaguas, Recreo, 23 Oct 1929, Williams, Ll. 3960 (holotype: F! [V0040605F]; isotype: S [S-R-7031]).

Pseudoxandra   williamsii   (R.E.Fr.) R.E.Fr., Acta Horti Bergiani 12: 227, f. 2b,c. 1937.














Cremastosperma yamayakatense Pirie

Pirie, Michael D., Chatrou, Lars W. & Maas, Paul J. M. 2018

Cremastosperma yamayakatense

Pirie 2004