Neobertiera pakaraimensis Delprete, 2015

Delprete, Piero G., 2015, Revision of Neobertiera (Rubiaceae, Sipaneeae) with observations on distyly, and three new species from the Guianas, Phytotaxa 206 (1), pp. 118-132 : 126-131

3. Neobertiera pakaraimensis Delprete , sp. nov. ( Figs. 2, 5).

Type:— GUYANA. Potaro-Siparuni Region, Pakaraima Mountains, Mount Wokomung, across slope to SW 0.5 km from headwaters of Wusupubaru Creek , montane slope forest, W aspect, upper canopy 20 − 35 m, 2-storied, epiphytes abundant, incl. 0.5 hectare tree fall, shrub 0.5 m [tall], filaments white, 5°03’N, 59°53’W, 975 − 1125 m, 17 February 1993 (fl), T. W. Henkel, M. Chin & W. Ryan 1449 (holotype, CAY 079485 ; isotypes, CAY 079486 , MO not seen, US not seen).

Shrubs, 0.5 − 4 m tall, erect or basally decumbent, sparsely branched; branches sparsely to densely appressed strigose; rooting at basal nodes and internodes. Stipules ovate to broadly ovate, 4 − 5.5 × 2.5 − 3 mm, bifid, appressed-strigose. Leaves petiolate; petioles 6.5 − 11.5 mm long, densely adpressed-strigose; blades narrowly elliptic, lanceolate to narrowly oblong-elliptic, 4 − 10.5 × 0.7 − 2.5 cm, acute-decurrent at base, acute and acuminate at apex, chartaceous, drying dark brown above and olive-green below, sparsely adpressed strigose above, sparsely short- to long-strigose below, midvein and secondary veins densely strigose below; secondary veins 8 − 10 each side of midrib, evident only below, immersed in the lamina above. Inflorescence laxely cymose during anthesis; peduncles 1.7 − 4 cm long; rachis stout, appressed white-pubescent, 5.5 − 6.5 cm long when fully expanded, with 1 − 3 pairs of lateral branches; lower lateral branches 2.5 − 3.5 cm long (excluding flowers); lateral branches dichotomously divided, with one pedicellate flower at the base of each bifurcation, ultimate branches scorpiod when fully expanded; bracteoles opposite to the insertion of each flower, linear-lanceolate, 1.5 − 2 × 0.2 − 0.4 mm, adpressed-pubescent. Flowers 4 − 5-merous, pedicellate; pedicels 1 − 1.5 mm long, densely appressed strigose. Hypanthium globose to obovoid, ca. 1 mm long, adpressed strigose. Calyx lobes narrowly lanceolate, frequently unequal, 2 − 3 × 0.3 − 0.4 mm, adpressed strigose outside. Corolla hypocrateriform, white, 4.8 − 5 mm long; tube narrowly cylindrical, slightly wider at mouth, 4.5 mm long, adpressely strigose-sericeous outside, puberulent inside, with a narrow line of yellow, moniliform hairs at mouth inside; lobes 5, oblong, 3 − 3.2 × 1.1 − 1.2 mm, round to obtuse at apex, glabrous on both sides. Long-styled flowers: stamens inserted 1.8 mm from the base of corolla tube; filaments 0.7 − 1 mm long; anthers linear, 1.2 × 0.2 mm, acute at both ends; style slightly longer than the corolla tube, 4.5 − 5 mm long, glabrous; style branches partially exserted, narrowly oblong, 0.9 − 1 mm long, acute at apex, densely papillose when receptive. Short-styled flowers: unknown. Fruits and seeds unknown.

Distribution and ecology ( Fig. 2):—Only known from two collections in Guyana, in the Pakaraima Mountain Range, eastern portion of the Roraima Massif, growing at river margins inside wet forest; with one collection at 120 m and the other at 975 − 1125 m elevation.

Phenology:—The two flowering collections were made in February.

Suggested conservation status: —Up to now this species is known only from two small populations (number of individuals per population unknown), indicating that it is rare. Taking into account the small area of occupancy of the only two collections known, this species is treated as “Endangered” (EN) following IUCN criteria ( IUCN 2001).

Etymology: —The specific epithet refers to the Pakaraima Mountain Region, where this species was collected.

Additional specimens examined (paratypes): GUYANA: Kuyuni-Mazaruni Region, Eping River, common along river, 6°00’N, 60°10’W, 120 m, 6 February 1991 (fl), T. McDowell & A. Stobey 3853 (CAY, MO not seen, US).

4. Neobertiera gracilis Wernham (1917: 169) . Type : Guyana. Macouria River, November 1886 (fl), G. S. Jenman 2388 (holotype, BM; isotype, K). ( Figs. 2, 6 )

Note: Wernham (1917: 169) described the locality of the type specimen as “ British Guiana, Macouria River (not far west of Cayenne), Jenman 2388.” The Macouria River is in Guyana, but he confused this river with the village of Macouria, which is located “not far west of Cayenne” and is in French Guiana.

Perennial herbs or shrubs, 0.5 − 4 m tall, erect, sparsely branched; branches densely appressed strigose. Stipules ovate to broadly ovate, 3 − 4.5 × 2.5 − 3.5 mm, acuminate at apex, appressed strigose. Leaves petiolate; petioles 3 − 9 mm long, adpressed-strigose-pubescent; blades elliptic, oblong-elliptic to oblanceolate, 4.5 − 13.5 × 2 − 5 cm, acute-decurrent at base, acute at apex, chartaceous, drying pale brown above and olive-green below, sparsely adpressed strigose above and below, midvein densely strigose above and below; secondary veins 9 − 14 each side. Inflorescences laxely cymose during anthesis; peduncles 2 − 3.5 cm long; rachis slender to filiform, appressed white-pubescent, 5.5 − 7.5 cm long when inflorescences fully expanded, with 2 − 3 pairs of lateral branches; lower lateral branches 1.5 − 4 cm long (excluding flowers); lateral branches dichotomously divided, with one pedicellate flower at the base of each bifurcation, ultimate branches scorpiod when fully expanded; bracteoles opposite to the insertion of each flower, linear-lanceolate, 1.5 − 2 × 0.2 − 0.4 mm, adpressed-pubescent. Flowers 4 − 5-merous, pedicellate; pedicels filiform, 0.5 − 1(− 1.5) mm long. Hypanthium obovoid, 0.7 − 1 mm long, adpressed strigose. Calyx lobes narrowly lanceolate, frequently unequal, 2.5 − 5 × 0.2 − 0.3 mm, adpressed strigose outside. Corollas hypocrateriform, white, 11 − 13.5 mm long; tube narrowly cylindrical, slightly wider at mouth, 5.5 − 11 mm long, adpressed strigose-sericeous outside, puberulent inside, with a narrow line of yellow, moniliform hairs at mouth inside; lobes 4 − 5, narrowly oblong, 5.5 − 7.5 × 1-2 mm, acute at apex, glabrous on both sides. Long-styled flowers: stamens inserted at 2 − 3 mm from base of corolla tube; filaments 0.5 − 1 mm long; anthers linear, 0.9 − 1.8 × 0.1 − 0.2 mm; style about the same length or slightly longer than the corolla tube, 6 − 11.5 mm long, glabrous; style branches narrowly oblong to linear, 0.8 − 1.5 mm long, acute at apex, densely papillose when receptive. Short-styled flowers: stamens inserted at distal portion of corolla, at 5.5-6 mm from base of corolla tube in flowers with corolla tube 7.5 − 8.5 mm long; filaments ca. 1 mm long; anthers linear, 1.5 × 0.2 mm, acute at both ends; style much shorter than corolla tube, 4 − 4.5 mm long, glabrous; style branches narrowly oblong, 1.4 mm long, densely papillose when receptive. Fruits 2.5 − 3 mm diam., sparsely strigose-sericeous. Seeds ca. 0.3 mm long, microscopically foveolate (barely visible at 50× magnification.

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FIGURE 5. Neobertiera pakaraimensis . A. Branch with a young inflorescence. B. Branch with a fully developed inflorescence. C. Node with stipule. D. Dissected long-styled flower, with stamens inserted at the middle of the corolla tube. Drawn from Henkel et al. 1449 (CAY). Illustration by Piero G. Delprete.

Distribution and ecology ( Fig. 2):—Known from 16 collections made in Guyana, in the Potaro-Siparuni Region, and two collections from Suriname, in the Wilhelmina Mountains, growing at the edge or inside wet forests, often near waterfalls, in alluvial or white-sand soils; from sea level to 900 m elevation.

Phenology:—Most specimens examined have flower buds, flowers in anthesis and mature fruits in the same inflorescence or on the same branch; these specimens were collected in April, June, July, August, September and November. The two specimens collected in June and July have flowers in full anthesis and some flower buds, but no fruits.

Suggested conservation status: —This species is known from many remote collection localities in Guyana and Suriname. However, the size of the populations is unknown and no recent observations in its natural environment are available, as no material has been recently collected. Therefore, taking into account the several sites where it has been collected, this species is here treated as “Least Concerned” (LC) following IUCN criteria ( IUCN 2001).

Etymology: —The specific epithet refers to the filiform inflorescence rachis of the species.

Additional specimens examined: GUYANA: Rockstone , June 1904 (fl, fr), A. B. Bartlett 8547 ( K, L) ; Moraballi Creek , Essequibo River, 3 October 1938 (fl–fr), Forest Department of British Guiana F120 ( K [2]) ; Tumatumari , 18–20 June 1921 (fl), H. A. Gleason 6 [= Appun 331] ( NY, US) ; rockstone, 13–30 July 1921 (fl), Gleason 483 ( NY, US) ; Potaro River , Amatuk Mountain, 1–2 April 1958 (fl, fr), V. Graham 193 ( K) ; Rockstone , Essequibo River, 25 m, 20 April 1976 (fl), M. S. Grewal & R. Persaud 110 ( L) ; Potaro River , Garraway Stream, 25 April 1944 (fl, fr), B. Maguire & D. B. Fanshawe 22964 ( F, L, MO, NY, US) ; Potaro River , below Kaieteur, September-October 1881, G. S. Jenman 945 ( K) ; Demerara River , March 1898 (fl), G. S. Jenman 7338 ( K) ; Moraballi Creek , Essequibo River, May 1932 (fl), E. B. Martyn 381 ( K) ; Potaro-Siparuni Region, from camp on Elizabeth Creek , ca. 1 km along rd to NE and along creek, 5°18’N, 59°05’W, 120 m, 16 October 1990 (fl, fr), T. McDowell & D. Goupal 3571 ( MO, US) ; Essequibo River , Moraballi Creek, near Bartica, near sea level, 14 September 1929 (fl), N. Y. Sandwith 256 ( K, L, NY) ; Basin of Essequibo River, Head Falls, 6 ° 7'N, 20 September 1937 (fl), A. C. Smith 2106 ( F, L, NY, US) ; Potaro Rd , June 1910 (fl, fr), F. A. Stockdale 8775 ( K) ; ca. 83 miles, Bartica–Potaro rd. , Amatuk Fall, 26 August 1933 (fl, fr), T. G. Tutin 602 ( BM, K, US) ; Potaro River , Amatuk Mountain, ca. 67 m, 23 July 1959 (fl), B. A. Whitton 5 ( K) .

SURINAME: Wilhelmina Geberte , forested lower slopes of Frederik Top, 3.5 km SSE of Juliana Top, 3°36’ − 41’ N, 56°30 − 34’ W, 500 m, 20 August 1963 (fr), H. S. Irwin, G. T. Prance, T. R. Soderstrom & N. Holmgren 54918 ( L, NY) ; Wilhelmina Mountains , top 1059, SE of Julianatop, 900 m, 24 July 1963 (fl), J. P. Schultz & J. G. Wessels Boer LBB 10223 ( BBS, L, MO) ; Wilhelmina Mountains , nameless top SE of camp km 14 in line to Lucie River, 700 m, 24 July 1963 (fl), J. P. Schultz LBB 10471 ( BBS, K, L, NY) .

Figures

FIGURE 6. Neobertiera gracilis. A. Habit. B. Node with stipule. C. Detail of a lateral branch of a fully developed inflorescence. D. Dissected short-styled flower, with stamens inserted at the upper portion of the corolla tube. E. Dissected long-styled flower, with stamens inserted at the middle of the corolla tube. F. Fruit. A−B: drawn from Maguire & Fanshawe 22964 (F); C: drawn from Gleason 6 (US) D: drawn from Grewal & Persaud 110 (L); E: drawn from Schultz & Wessels Boer LBB 10223 (L); F: drawn from Smith 2106 (US). Illustration by Piero G. Delprete.