Glandonia williamsii Steyerm., Fieldiana Bot.

Guesdon, Isabel Reis, Amorim, André Márcio & Meira, Renata Maria Strozi Alves, 2018, The hydrochorous Amazonian genus Glandonia (Malpighiaceae): new records, morphoanatomy updates and taxonomic contributions, Phytotaxa 345 (1), pp. 13-25 : 23-24

3. Glandonia williamsii Steyerm., Fieldiana Bot. 28(2): 288. 1952.

Type:— VENEZUELA. Amazonas: Alto Orinoco , 2 February 1942, L. Williams 14154 (holotype F; isotypes G, MICH, VEN!) .

( Figures 1C ; 2C ; 3A, F, G ; 4C–E, I, M–O ; 5G–I )

Description— Small trees, 4–8(–15) m tall, branches glabrous. Leaf entire, lamina 9–22(–26) × 3–10.8 cm, elliptical, base rounded, apex acuminate, margin revolute, coriaceous, adaxial and abaxial surfaces sparsely sericeous to glabrescent, abaxial surface papillose, with (0)2–4 basilaminar yellowish green conspicuous glands, 1.2–1.8 mm diameter, laterally positioned at the midrib, smaller conspicuous glands randomly distributed throughout the leaf blade, 0.6–1 mm diameter; veins abaxially prominent; median portion of leaf keel shaped; petiole 10–24(–29) mm long, glabrous; stipules 9–21(–35) mm long, glabrous. Inflorescence a raceme of cincinni, 5–18 cm long, appressed-tomentose, cincinni with 3–5 flowers; bracts and bracteoles ovate, apex slightly acute, concave, abaxially sericeous; bracts 3–5 mm long, eglandular; bracteoles 2–3 mm long, bracteole gland creamy-white, discoid-convex secretory surface. Floriferous peduncle 2–4 mm long. Pedicel 8–10 mm long, appressed-tomentose, joint distinct. Sepals 1.5–2 mm long beyond the sepal glands, apex rounded, abaxially sericeous, sepal glands 1.8–3.2 mm long, white. Petals glabrous, outermost petal helmet-shaped, white, limb 4–6 × 4–4.5 mm, denticulate, claw 3–4 mm long, reflexed; lateral petals white, limb 4–6 × 4–5 mm, sagittate, eglandular, margin entire, claw 3.5–4.5 mm long, reflexed; posterior petal yellow, limb 4–5.5 × 3–5 mm, erect, sagittate, with ca. 18 small and marginal glands on the proximal portion, ca. 0.1 × 0.2 mm, claw ca. 3.5 mm long, erect. Filaments 1–1.3 mm long, densely hirsute just above of the insertion of the anther; anthers 3.5–5 mm long. Ovary ca. 1.3 mm long, pyramidal, glabrous; styles three, 4.5–5.5 mm long, subequal, glabrous, ca. 0.5 mm bent at apex toward the center of flower. Fruit (1.3–)1.4–2.4 × 0.8–1.6 cm, cylindrical, becoming slightly acute-conoid, with ca. 8 longitudinal grooves, forming rounded projections at the base, styles persistent.

Specimens examined— BRAZIL. AMAZONAS: São Gabriel da Cachoeira , Cachoeira Maçarico, 26 April 1947 (fr), R. L. Fróes 22233 ( IAN) ; ibid., Içana, Rio Negro , 05 May 1947 (fl), R. L. Fróes 22280 ( MG) ; ibid. Rio Negro , 1947 (fr), R. E. Schultes 9565 ( IAN) ; ibid. 26 December 1931 (bud, fl) A. Ducke s.n., ( RB 213108 ) ; ibid., Rio Negro, Rio Cauaburi , 16 June 1976 (fr), L. F. Coelho 484 ( INPA; MG) ; ibid., Rio Curicuriari , 12 July 1979 (fr), J. M. Pires & N. T. Silva 7970 ( MG) ; ibid., Rio Negro, Igarapé Toury , 18 March 1952 (bud, fl), R. L. Fróes 27909 ( IAN) ; ibid., Rio Uneiuxi , 22 October 1971 (bud), G. T. Prance et al. s.n. ( INPA 33733 ) ; Rio Urubaxi , 4 June 1976 (fr), L. R. Marinho 420 ( IAN) ; ibid., Rio Uapés, Taraquá, Igarapé da Chuva , 9 January 2015 (bud, fl), I. R. Silva-Guesdon et al. 290 ( VIC) ; ibid., 7 June 1962 (fr), O. C. Nascimento 575 ( IAN) . COLOMBIA. VAUPÉS: Mitú, Rio Vaupés , 19 November 1976 (bud, fl), J. L. Zarucchi s.n. ( COL 172039 ; INPA 76785 ) . GUYANA: Caño Minas , abajo de Sejalito, 05 March 1995 (ste), M. P. Córdoba et al. 979 ( COL) . VENEZUELA. AMAZONAS: Atabapo , confluencia del Caño Yagua em el Orinoco, May 1990 (fr), E. Marin s.n. ( PORT 62675 ) ; Autana, Rio Cuao , entre Piedra Picure y Santa Elena, 14 August 1997 (fr), A. Castillo 5079 ( VEN) ; Autana, Rio Cuao, entre Raudal del Danto e Isla Picurela, 29 January 1997 (fr), A. Castillo 4488 ( VEN) ; Caño Yagua , November 1989 (fl), E. Marin s.n. ( PORT 52001 ) ; Casiquiare , April 2000 (ste), B. Stergios et al. s.n. ( GUYN 12943 ) ; ibid., April 2000 (ste), B. Stergios, & W. Schargel s.n. ( PORT 72216 ) ; ibid., Caño San Miguel , 18 April 1991 (fr), G. Aymard s.n. ( PORT 58955 ) ; Casiquiare , 12 December 1945 (fl), R. L. Fróes 21509 ( IAN) ; ibid., Rio Negro , 3 February 1992 (bud, fl), B. Stergios et al. s.n. ( PORT 67208 ) ; Entre Caño Cotúa y Cerro Yapacana , November 1989 (bud, fl), E. Marin s.n. ( PORT 60136 ; GUYN 7507 ) ; Laja Cúcuta, Rio Atacavi , November 1989 (bud, fl), J. Velazco s.n. ( PORT 41135 ) ; Médio Rio Ventuari , March 2002 (ste), B. Stergios, F. Molina & A. Vicentini s.n. ( PORT 82468 ) ; Rio Casiquiare, Caño Kuka , 10–22 February 1989 (fl, fr), B. Stergios et al. s.n. ( PORT 42084 ) ; Rio Esoni , 16–27 January 1987 (fr), B. Stergios, G. Aymard & R. Estévez s.n. ( PORT 32975 ) ; Rio Guayapo , May 1989 (fr), E. Foldats & J. Velazco s.n. ( PORT 49490 ) ; Rio Negro, cerca Rio Pasimoni , 9 February 1981 (bud, fl, fr), O. Huber & E. Medina s.n. ( COL 259369 ; MG 107371 ) ; s l., 18 February 1986 (bud, fl), B. Stergios & G. Aymard s.n. ( PORT 31685 ) ; Rio Sipapo , cerca de Cerro Pelota, 22 February 2001 (fl), A. Castillo & B. Camaripano. 8995 ( VEN) ; ibid., entre Cano Veneno y Pendare , margen izquerda, 19 February 2001 (bud, fl), A. Castillo & B. Camaripano. 8242 ( VEN) ; Rio Varía , April 1991 (fl), J. Velazco s.n. ( PORT 51484 ) ; ibid., 7 November 1994 (bud, fl), B. Stergios et al. s.n. ( PORT 61007 ; VEN 288790 ) ; ibid., Caño Eruvichi , 14 April 2005 (bud, fr), W. Diaz 7477 ( GUYN) ; Rio Yatuá , 30 January 2005 (bud), K. M. Redden 3408 ( GUYN) ; Yapacana , 20 March 1953 (fr), B. Maguire & J. J. Wurdack s.n. ( VEN 178462 ) .

Notes on morpho-anatomy— The leaves of Glandonia williamsii are exclusively keel-shaped and coriaceous ( Fig. 3A ). The pedicel joint of G. williamsii is distinct, as in G. prancei . Field observations of fresh material revealed that the leaf glands are yellowish-green ( Fig. 3F ), that the posterior petal is yellow and its limb erect ( Fig. 5G ). The laminar glands of G. williamsii are larger than those of G. macrocarpa and G. prancei ( Fig. 4I ) and can be seen with the naked eye ( Fig. 3G ). In G. williamsii , the abaxial epidermal leaf cells are always papillose ( Fig. 4C–E ) and the outline of the anticlinal walls curved. The pattern of the vascular system in the petiole is similar to G. prancei . Brachysclereids and macrosclereids in the posterior petal were observed only of G. williamsii ( Fig. 4M–O ) and the posterior petal glands are the smallest in the genus. The fruit differs from the other two species by its slightly acute apex ( Fig. 2C ).

Etymology— The specific epithet pays homage to Llewelyn Williams who collected the type specimen.

Distribution, habitat and conservation— Glandonia williamsii occurs on the lower Rio Uaupés, upper Rio Negro and Rio Orinoco, including areas of igapó in Colombia, Venezuela and Brazil ( Fig. 1A ). According to its EOO, G. williamsii is categorized as Least Concern (LC). Although the AOO = 200,000 km 2 suggests an endanger status, most of the area effectively occupied by this species in Brazil is within conservation and indigenous protected land.

Phenology— Glandonia williamsii has been collected in flowers from October to May and in fruit from January to August.

Figures

FIGURE 1. A. Map showing the distribution of Glandonia macrocarpa (black triangles), G. prancei (black circles) and G. williamsii (black squares). B. Glandonia macrocarpa specimen (arrow) in terra firme forest. C. Glandonia williamsii specimen (arrow) in igapó. D. Hydrochorous fruit of G. prancei.

FIGURE 2. General view of Glandonia species: A and B Glandonia macrocarpa: A. Flowering branch, B. lateral and frontal view of fruit. C. Fruiting branch of G. williamsii. D. Fruiting branch of G. prancei. Drawing A from Guesdon 16 (INPA), B from Ducke 793 (INPA), C from Fróes 28782 (MG) and D from Prance et al. 20557 (INPA).

FIGURE 3. Vegetative and reproductive characters of Glandonia species: A. keel-shaped leaves of G. williamsii, B. and C. general view of leaves and inflorescence of G. prancei. Basilaminar leaf glands: D. Glandonia macrocarpa, E. Glandonia prancei and F. Glandonia williamsii. Laminar leaf glands: G. Glandonia williamsii and H. Glandonia macrocarpa. Floral glands: I. bracteole gland (BG) of G. macrocarpa, J. bracteole and sepal glands of G. prancei (BG and SG, respectively), black arrow: pedicel joint. K. Posterior petal in bud of G. macrocarpa, note the petal glands (arrow) L. Helmet-shaped petal (HP) and reflexed limb of posterior petal (PP) in G. macrocarpa.

FIGURE 4. Anatomical characters of Glandonia species. A. Adaxial surface of G. macrocarpa showing indument scars (black arrow). B. Abaxial surface of G. prancei showing a stoma (black arrow) and sinuous outline of the anticlinal epidermal wall. Abaxial surface of G. williamsii C. papillae covering a stoma (black arrow), D. papillose surface (SEM image), a stoma (white arrow). E. Transversal section of leaf of G. williamsii, papillae (white arrow), F. Sclereids in midrib of G. macrocarpa (black arrow). Diagrammatic schemas of petiolar vascular systems G. a curved arc with invaginated ends in G. prancei and H. a concentric arc delimiting a central pith in G. macrocarpa, dot-filled areas: phloem, striped areas: xylem. Leaf blade cleared I. in G. williamsii and J. in G. prancei, note the laminar gland (arrow). Transversal view of bracteole gland K. convex surface in G. macrocarpa, L. truncate surface in G. prancei. M–O. Sclereids on posterior petal of G. williamsii, N. Macrosclereids, O. Brachysclereids.

FIGURE 5. Morphoanatomical floral characters of Glandonia species. A–C: Glandonia macrocarpa: A. General view of the flowers, B. Posterior petal margin (SEM image) and C. Posterior petal cleared. D–F: Glandonia prancei: D. General view of the flowers, E. Posterior petal margin (SEM image) and F. Posterior petal cleared; G–I: Glandonia williamsii: G. General view of the flowers H. Posterior petal margin (SEM image) and I. Posterior petal cleared. PP: Posterior petal. SG: Sepal glands. BG: Bracteole gland.