Dalechampia spathulata (Scheidw.) Baill.

van Welzen, P. C. & Winkel, E., 2022, The Malesian species of Dalechampia (Euphorbiaceae), Blumea 67 (1), pp. 26-32 : 29-31

2. Dalechampia spathulata (Scheidw.) Baill. — Fig. 2

Dalechampia spathulata (Scheidw.) Baill.(1858) 487; Backer & Bakh. f.(1963) 493; Armbr. (1988) 309. ― Cremophyllum spathulatum Scheidw. (1842) 24. ― Type: Not indicated, described from plants introduced from Brazil in 1839 and cultivated and flowering in Bruxelles in 1841 ( Armbruster 1988).

Dalechampia roezliana Müll.Arg. (1866) 1233. ― Dalechampia roezliana Müll.Arg. var. rosea Müll.Arg. (1866) 1233, nom. inval., not homonym. ― Lectotype (designated here): Roezl s.n./Ortgies s.n. (lecto G [G317251*]), Mexico, Veracruz, Sontecomapan. Müller did not describe a variety that could be considered a homonym, but only under var. rosea a reference to Roezl is given.

Dalechampia roezliana Müll.Arg. var. viridis Müll.Arg. (1866) 1234. ― Type: Hort. Van Houtte / Ortgies s.n. (holo G [ G317252 *]), cultivated in hortus Ghent: Van Houtte.

Dalechampia roezliana Müll.Arg. var. alba W. Bull (1875) 557. ― Type: Not indicated.

Dalechampia spathulata (Scheidw.) Baill. var. alba G. Nicholson (1885) 439. ― Type: Not indicated (may be based on the former name, but no refer- ence to it).

Shrublet, erect, to 80 cm high, stem simple or sparsely branch- ed; flowering branches 2–2.5 mm diam, somewhat flattened, indumentum of more or less adpressed, long and/or short trichomes, glabrescent. Stipules falcately ovate, 9–13.5 by 3.5– 5.5 mm, base broad, convex on stem, margin entire, apex acute, rather persistent, outside either short or some long adpressed trichomes, venation distinct, parallel. Leaves: petiole completely pulvinate, 0.3–1.5 cm long, above flattened, short or long appressed hairy, sometimes glabrescent; blades spathulateobovate, 9.7–26 by 3.7–8.8 cm, 2.4–3.7 times longer than wide, papery, symmetric, tapering towards the sometimes slightly widened, narrowly, shallowly, emarginate base, seldom widened into small lobes, with two small, upright adaxial glands at connection with petiole, margin subentire to laxly serrate or crenate, especially in wider part, teeth with a glandular erect yellowish tooth abaxially, flat to slightly revolute, apex acuminate and mucronate, surfaces drying dark brown or greenish above, lighter underneath; on both sides venation distinct, glabrous or hispid trichomes along midrib, glabrescent, second order veins 12–20 per side till apex, bent upwards and closed near margin, tertiary order veins subscalariform to reticulate, higher orders reticulate. Peduncle shortly sericeous. Bracts white to pink: lower bract ovate, c. 4.7 by 3.5 cm, base broadly attenu- ate, margin serrate, teeth ending in upward pointing glands, apex acute, very short trichomes along margin and on nerves on both sides, very strongly 3-nerved basally; basally on both sides a bracteole, recurved, falcately ovate, c. 10 by 5.5 mm, base one side much longer, touching other bracteole, margin entire, apex acute, venation ± parallel, especially midrib distinct, margin and outside with few trichomes, inside glabrous; upper bract idem, c. 4.2 by 4.2 cm; bracteoles falcately ovate, c. 9.5 by 4 mm, mainly only margin hairy. Pistillate part: bract to pistillate flowers ovate, c. 9 by 5.3 mm, symmetric, margin entire, slightly shortly hairy, apex rounded, slightly 2- or 3-serrate; venation indistinct; bracteoles narrowly triangular, c. 4.8 by 0.7 mm, margin entire, slightly hairy; floral parts often with stinging Urticaceae -like trichomes, a thicker capillary basal part and a narrower point. Pistillate flowers 3 in a cyme; petioles c. tri- angular in transverse section, that of central flower c. 2.3 mm long, those of side-flowers c. 1 mm long, shortly hairy, sturdy, gradually widening towards apex; sepals 6, in 2 rows, long triangular, erect, apex ending in gland, outer slightly longer or shorter but always broader than inner, c. 5.3 by 0.9 mm, inner c. 5.2 by 0.7 mm, margin sometimes with a single serration at one side ending in a glandular tip, outside and margin hairy with soft trichomes, inside glabrous; erect glands in between sepals, c. 0.5 mm long, sometimes growing into short, sepallike organs; ovary 3-locular, 3-lobed, c. 1.2 mm high by 1.7 mm wide, with long hispid trichomes, style to 17.3 mm long, hairy, slightly triangular in transverse section, in basal third with long triangular darker green surfaces, stigmatic apex slightly bent, circular, forming 3 only slightly raised knobs, not thickened. Staminate part on c. 4 mm long peduncle, broadening upwards, very sturdy, somewhat triangular, hairy; bracts 4, old, upright, ovate to somewhat obovate, 5–7.3 by 4–5 mm, outward and margin subglabrous; staminate flowers c. 9, petiole c. 7.8 mm long, upper part above abscission zone slightly thicker; sepals 4, long-ovate, c. 5.3 by 1.8 mm, valvate, apex ending in a gland, pinkish, outside and margin somewhat hairy; androphore c. 4 mm long, round in transverse section, hairy, white, free filament part c. 0.3 mm long, thin, anthers c. 12, subbasally attached, elliptic to somewhat triangular, c. 0.6 by 0.4 mm, bent downward and opening with seemingly 2 lengthwise slits with an indusium-like side, back of anther quite hard; staminodial bractlets many, stems 4.5–6.5 mm long, slender near flowers, then with a single bright yellow, shiny, apical gland, c. 0.8 mm long, further from flowers much thicker and with many apical glands. Fruits 3-lobed, c. 0.5 cm high by 0.8–1 cm wide, con- taining 3 globose seeds.

Distribution ― South Mexico to Peru. Malesia: occasionally cultivated on Java (Backer & Bakhuizen van den Brink f. 1963).

Habitat & Ecology ― Edge of somewhat disturbed rain for- est. Flowering: March, August to November; fruiting: March, October. Altitude: c. 100 m. A shift in pollinators occurred, D. spathulata is not pollinated by female bees collecting resin, but by male Eulaema (Euglossinoid) bees, which use the fragrance-emitting monoterpenes of the staminate glands as an odorant ( Armbruster & Webster 1979, Armbruster 1988). The staminate glands do not contain resin.

Figures

Fig. 2 Dalechampia spathulata (Scheidw.) Baill. a. Inflorescence with pistillate part (left) and staminate part (right, one staminate flower flowering, also showing dense groups of sterile staminodial bractlets; 2 bracts and 4 bracteoles to inflorescence removed); b. staminate part of inflorescence, flowers either caducous or in bud, in background glandular staminodial bractlets; c. anthers; d. pistillate part of inflorescence (2 bracts to the inflorescence removed, scar of one visible, 4 bracteoles of both bracts visible, 2 pointing downwards, 2 in back, bract, pointing to front, and small triangular bracteoles to pistillate flowers visible, cyme of 3 pistillate flowers); e. lateral pistillate flower; f. central pistillate flower; g. hairy ovary and basal part of style with two differently coloured parts (sepals removed); h. gland between sepals; i. glands at tip of sepals (based on fresh material from Hortus botanicus, Leiden University, no. HBL20150165). — Drawn by Esmée Winkel.