Notopleura altsonii (Sandwith) 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

Notopleura altsonii (Sandwith) O.Lachenaud & Delprete comb. nov.

Cephaelis altsonii Sandwith, Bulletin of Miscellaneous Information, Royal Gardens, Kew 1931: 475 ( Sandwith 1931)

Psychotria altsonii (Sandwith) Steyerm. ( Steyermark 1972: 555)

Carapichea altsonii (Sandwith) C.M.Taylor ( Taylor and Gereau 2013: 121)

Type.

GUYANA - Cuyuni-Mazaruni Region • Macreba Falls, Kurupung River ; Aug. 1925; fl. & fr. imm.; Altson 322; lectotype: K [K000174497], designated by Taylor and Gereau (2013: 121); isolectotypes: K [K000174398], NY [00131011]; photo-K at NY .

Description.

Shrub, 1.5-3 m tall, single-stemmed, glabrous; distal internodes terete, 4.5-8.0 mm in diam., somewhat succulent, glabrous. Stipules consisting of a persistent, truncate sheath (absent in flower-bearing nodes), 2.5-3.5 × 6.5-14 mm, glabrous, and a dense mass of basal linear appendages 1.0-2.5 mm long, very early caducous, leaving a scar. Leaves with petioles 1.0-5.5 cm long, glabrous; blades elliptic to oblanceolate, 14-35 × 4.5-10 cm, acute-decurrent at base, acute and long-acuminate at apex, acumen narrowly triangular, 1-2 cm long, somewhat succulent to fleshy when fresh, drying papyraceous, dark brown above and pale brown to pinkish-brown below, glabrous throughout; secondary veins 18-21 on each side of midrib; embedded in the lamina, barely visible above and obsolete below in dried specimens; intersecondary veins 1-3 between each couple of secondary veins, terminating far from the margin; tertiary veins invisible, embedded within the lamina; domatia absent. Inflorescence terminal, long-pedunculate, capitate; peduncles 7.5-17 cm long, glabrous, drying brownish-black; head multiflorous, subtended by a cup-shaped structure 3-5 mm long made by 4 bracts connate at base; free portion of bracts in two decussate pairs, unequal to subequal, obovate to broadly ovate, 1.5-2.7 × 0.9-3.2 cm, pale greenish-white, white or pale violet, often tinged with pink or purple, persistent, drying dark brown, glabrous; bracteoles subulate to lanceolate, 5-10 × 0.5-3.0 mm. Flowers 5-merous, subsessile to shortly pedicellate; pedicels to 2 mm long at flowering stage (to 3 mm long in fruiting stage). Hypanthium narrowly obovoid, 1.5-2.0 mm long, glabrous. Disk bilobed to the base, 0.5-0.8 mm long, glabrous. Calyx cupular, 0.7-1.2 mm long, truncate, slightly undulate or with minute teeth <0.2 mm long, glabrous. Corolla hypocrateriform, 10.5-15 mm long, glabrous, white with lobes yellow inside; tube subcylindrical, 9-12 mm long, 1-2 mm wide, glabrous outside and inside; lobes triangular to ovate, 1.5-3.0 × 1-2 mm, acute at apex, glabrous outside, papillose inside. Stamens inserted 3-4 mm from corolla base, anthers subsessile, included, narrowly oblong, 2-3 × 0.4 mm. Style glabrous, 10 mm long, barely exserted; stigmas linear, 1 mm long. Fruits (slightly immature) ovoid to ellipsoid, 4-6 × 2.0-3.5 mm, slightly costate when dry, white to pale violet. Pyrenes plano-convex, elliptic in outline, 4-6 × 2.0-3.5 mm, strongly compressed dorso-ventrally, dorsal side with 3 or 4 ridges, ventral side with 2 very shallow depressions separated by a longitudinal median crest. Seeds unknown.

Distribution.

Only known from the foothills and higher elevations of the Pakaraima Mountains, Guyana.

Ecology.

In understory of moist, non-flooded forest, commonly on boulders of sandstone or conglomerates; 85-1000 m elevation.

Phenology.

Specimens with flowers were collected from July to November, and with immature fruits in August.

Local names.

The two following vernacular names are reported in Akawai (Guyana): duma-ek (Altson 522) and waguk-wa-eba (Forest Department 2773).

Specimens examined.

GUYANA • near summit of Kurupung Mts on trail from Macreba Falls to Kamarang ; 13 Sep. 1938; fl.; Forest Department 2773; K • Pakaraima Mountains , Membaru-Kurupung trail, Dicymbe pole forest; 1000 m; 29 Oct.-4 Nov. 1951; fl.; Maguire & Fanshawe 32353; NY • Upper Mazaruni River , Kurupung River , Makreba Falls , on Kamarung trail; Sep. 1938 - Feb. 1939; fl.; Pinkus 5; NY • Pakaraima Mountains , Kurupung River, Makreba Falls; 17 Jul. 1992; fl.; Hoffman et al. 2050; MO , US.

Notes.

This species closely resembles N. nivea and N. sandwithiana ; differences between them are summarized in Table 3 .