Hiraea trianae C.E.Anderson, 2016

Anderson, C., 2016, Circumscription and nomenclature of Hiraea barclayana, H. reclinata, and H. ternifolia (Malpighiaceae), and of seven species misassigned to them, Blumea 61 (2), pp. 125-146 : 143

9. Hiraea trianae C.E.Anderson , sp. nov. — Fig. 9 ; Map 4

Differt a H. ternifolia foliis oppositis, laminae adaxaliter sericeae, et petalo postico margine apice digitato-fimbriato basi denticulato. — Type: Barclay et al. 3474 (holo US; iso COL, US, WAG), Colombia, Cundinamarca, S of Silvania on toll road to Fusagasugá ,near km 37,turn W and proceed for 4 km on road to Tibacuy , 1300 m, 30 May 1972 .

Hiraea ternifolia (Kunth) A.Juss.var. robustior Cuatrec.(1958) 401. — Type: García­Barriga 12313 (holo US;iso COL, US),Colombia, Cundinamarca,al oeste de Guadas,camino de herradura entre Guadas y el Alto de Aguaclara , hacienda ‘Paramillo’, 1040–1320 m, 24 July 1947.

Hiraea ternifolia (Kunth) A.Juss. var. robustior Cuatrec. forma glandulosa Cuatrec. (1958) 401. — Type: Mutis 2060 (holo US;iso MA, online image), Colombia, without locality.

Etymology. The specific epithet honours José Jerónimo Triana (1834– 1890), whose collections and writings greatly advanced comprehension of the Colombian flora.

Woody vine to 30 m; stems densely sericeous when young, becoming glabrous. Leaves opposite. Laminas of the larger leaves 7.5–17 by 4.5–9.5 cm, elliptical, apex mucronate, base truncate to slightly cordate, mature laminas coriaceous and bullate, adaxially with sessile to subsessile hairs when young, soon glabrescent to glabrous but with some hairs retained on and along the costa and secondary veins, abaxially velutinous mixed with scattered T-shaped hairs, stalk to 0.2 mm long, arms of Y-shaped hairs 0.1–0.3 mm long, trabecula of T-shaped hairs 0.5–1.5 mm long, often crisped and intertwined; margin with scattered glands 0.2–0.3 mm diam in distal 1/4–1/2; costa and secondary veins impressed adaxially, prominent abaxially. Petioles 11–23 by 2–3 mm, densely velutinous, with a pair of glands at apex to 3 mm below apex, each gland 0.8–1.3 mm long, sometimes glands absent. Stipules 2.2–4 mm long, borne at middle to distal 1/4 of petiole. Inflorescences 1– 2 axillary ternate cymes, central umbel 4-flowered, lateral umbels 4– 6-flowered; umbel without a gland in the centre; inflorescence axis 1–4.5 mm long, bracts 1.5–1.8 mm long and wide; all peduncles sessile but the laterals ones often with a bract c. 1.5 mm long near the base; peduncles 2.5–13.5 mm long; bracts and bracteoles subtending pedicels 1.5–2 by 1.3–1.5 mm; pedicels 19–26 by 0.5–10 mm, densely covered with sessile to T-shaped hairs (stalk to 0.1 mm); axes and abaxial surface of bracts and bracteoles densely sericeous. Sepals 2.2–2.8 mm long and wide, triangular, adaxially glabrous, abaxially sericeous; anterior sepal eglandular, the lateral four biglandular, glands 1–1.5 mm long, or all sepals eglandular. Petals yellow, limb of posterior petal streaked with red, glabrous; lateral petals with the claw 2.5–3 mm long, limb of anterior-lateral petals c. 8 mm long and wide, orbicular, margin subentire, limb of posterior-lateral petals c. 7 mm long and wide, orbicular, margin finely denticulate distally, teeth to 0.1 mm long, subentire proximally; posterior petal with the claw 3.5–4 mm long and thicker than that of lateral petals, limb 6–6.5 mm long and wide, orbicular, margin glandular-digitate-fimbriate at apex, fimbriae to 0.8(–1) mm long, grading into denticulate toward the base, the teeth decreasing in size, erose near the base. Stamens glabrous, filaments basally connate. Stamen opposite anterior sepal: filament c. 4 mm long, anther c. 1.3 mm long; stamens opposite anterior-lateral petals: filaments c. 3.5 mm long, anthers 1.2–1.3 mm long; stamens opposite anterior-lateral sepals: filaments c. 3.8 mm long, anthers c. 1.2 mm long; stamens opposite posterior-lateral petals: filaments 2.7–3 mm long, anthers 1.2 mm long; stamens opposite posterior-lateral sepals: filaments 3.5–3.8 mm long, anthers c. 1 mm long; stamen opposite posterior petal: filament c. 2.5 mm long, anther c. 0.9 mm long. Styles glabrous, 3.5–3.7 by 0.4–0.5 mm; anterior style slightly incurved, apex extended into a spur 0.1–0.2 mm long; posterior styles incurved, apex extended into a spur 0.05–0.1 mm long. Ovary c. 1.5 mm long, densely villous. Samara not seen.

Distribution — Colombia (Cundinamarca, Norte de Santan- der, Tolima).

Habitat & Phenology — In forest; 600–1320 m; collected in flower in May and July.

Additional specimens examined. COLOMBIA, Cundinamarca, Junca, 1200m, Triana 3377 (G, K). Norte de Santander, ‘Provincia de Ocaña’, Schlim 324 ó 712 (COL). Tolima, Mariquita, 600 m, Triana 1202 ( US). Without locality, Mutis 5772 ( US).

Notes — Hiraea trianae was first described by Cuatrecasas (1958) as a variety of H. ternifolia , with which it shares abaxially velutinous leaves. It is here elevated to species level. It differs from H. ternifolia by its abaxial laminar pubescence, composed of sessile to subsessile hairs. The initially dense vesture is sloughed off in patches, and older leaves are glabrescent to eventually glabrous, though some hairs of usually retained along the costa. None of the collections seen exhibit ternate phyllotaxy. The inflorescence is a simple ternate cyme, one or two per leaf axil. The posterior petal is glandular-digitate-fimbriate only at the apex; the rest of the margin grades from denticulate to erose toward the base. Cuatrecasas named his variety ‘robustior’ to emphasize the thicker inflorescence axes and pedicels evident in the collections he saw. Yet, all of those have young inflorescences in bud or the flowers beginning to open. As inflorescences mature, the pedicels elongate and become thinner. This transition is well shown in the holotype. The type collection, Barclay et al. 3474, was distributed as annotated by Cuatrecasas as H. sclerophylla Cuatrec. , doubtlessly owing to an unfortunate error in handling annotation labels. Hiraea sclerophylla is immediately separated from H. trianae by the appressed abaxial laminar vesture.

Figures

Map 4 Distribution of Hiraea hookeriana A.Juss. (▲) and H. trianae (■).

Fig. 9 Hiraea trianae C.E.Anderson.a. Flowering branch; b. large leaf, adaxial view; c. base of lamina and apex of petiole with a pair of glands (almost hidden by vesture) and a pair of stipules, adaxial view; d. detail showing abaxial vesture of mature lamina; e. detail showing dense adaxial vesture of young lamina; f. posterior petal; g. posterior-lateral petal; h. anterior-lateral petal; i. androecium, first stamen at left opposite posterior petal; j. gynoecium, anterior style at left (from: a–d, f–g. Barclay et al. 3474, US; e. Triana s.n., G). — Scale bar: a–b = 4 cm; c = 8 mm; d–e = 4 mm; f–h = 6.7 mm; i–j = 2.7 mm. — Drawn by Karin Douthit.