Carapichea squamelligera (Steyerm.) O.Lachenaud & Delprete, 2022

Lachenaud, Olivier & Delprete, Piero, 2022, Revision of Carapichea (Rubiaceae - Psychotrieae) in the Guianas, with two new combinations and transfer of three species to Notopleura, Plant Ecology and Evolution 155 (2), pp. 275-300 : 275

7. Carapichea squamelligera (Steyerm.) O.Lachenaud & Delprete comb. nov.

Psychotria squamelligera Steyerm., Brittonia 36: 156 ( Steyermark 1984)

Type.

FRENCH GUIANA • sur la rivière Comté, en forêt sur la Montagne Soufflet; 12 Jun. 1975; fr.; Granville B-5288; holotype: VEN [No. 289722]; isotypes: CAY n.v., P [P06800571]

Description.

Shrub up to 1.5 m tall, branched; terminal branchlets terete, 1.5-2.5 mm in diam., glabrous, soon covered with a greyish-brown corky bark. Stipules free, narrowly triangular to lanceolate, 6-8 × 1.5-4.0 mm, entire, glabrous outside, villose at the base inside, becoming corky and soon damaged. Leaves with petioles 0.5-1.4 cm, glabrous; lamina elliptic, 8-18.5 × 1.8-6.7 cm, attenuate and decurrent on the petiole at base, acuminate at apex, slightly coriaceous when dry, entirely glabrous, drying dark brown or dark olive-green; midrib and secondary veins prominent on the upper side; secondary veins 6-9 on each side of the midrib, strongly ascending, curving towards the margin and almost reaching it; 2-3 intersecondary veins between each pair of secondary veins; tertiary veins reticulate, dense and conspicuous in the dry state. Inflorescences terminal, apparently erect, in involucrate heads, few-flowered; peduncle 4-5 cm long, glabrous; involucre orange, consisting of two unequal, decussate pairs of almost free bracts, the outer pair broadly obovate, 12-17 × 9-12 mm, the inner pair narrowly elliptic, 11 × 2.5-4.0 mm, both pairs erect, obtuse at apex, entirely glabrous, persistent in the fruiting stage; interfloral bracts numerous and much narrower than the involucral ones, linear, acute, ca 9 × 0.5 mm, glabrous, persistent in the fruiting stage. Flowers unknown. Calyx (in fruit) shortly cupuliform, truncate, ca 1 mm long, glabrous, persistent on fruit. Disk bilobed to the base, ca 1 mm long. Fruits narrowly ovoid, 12 × 5 mm when dry, glabrous, sessile. Pyrenes plano-convex, narrowly elliptic to oblong in outline, 11-14 × 4-7 mm, acute at apex, dorsal side nearly smooth with 3 very vague indications of ridges, ventral side with a deep longitudinal narrow excavation, ± C-shaped in cross-section, opening by 3 dorso-basal slits running along the ridges. Seeds entire, C-shaped in cross-section.

Distribution. Endemic to northeastern French Guiana, only known from the type specimen collected on Montagne Soufflet.

Ecology. The type label only reports that the specimen was collected in forest, without indicating the elevation.

Phenology.

The only known specimen, with fruits, was collected in June.

Notes. This species is only known from the fruiting type specimen. Presumably due to the incompleteness of the material, Steyermark (1984) noted that its immediate relationships were not evident. However, it closely resembles C. guianensis and C. galbaoensis in the marcescent stipules and in the shape, texture, and venation of the leaves - the three species being virtually indistinguishable in vegetative state - as well as in the shape and mode of opening of the pyrenes. The three species also share inflorescences with two pairs of involucral bracts - although Steyermark (1984) described and illustrated only one pair of involucral bracts in C. squamelligera , two pairs are actually present - and the flowers are surrounded by numerous bracteoles. They can be separated by the characters summarized in Table 2 . The above description is mostly based on the P isotype; the holotype in VEN was seen as a photograph only, and an isotype from CAY cited in the original description was sent on loan to VEN in 1981 but has not been returned.