ALBERT

Description: This project of the Royal Botanic Garden Edinburgh aims to provide regional manuals and on-line identification computer programs to the timber species of Dipterocarpaceae. The Singapore manual is a first trial, later editions should include other islands in the Malay Archipelago. The possibility is also offered to have tailor-made manuals for specific regions against cost price. Many data have been gathered, especially vegetative characters one can readily observe while standing underneath these enormous trees. In this respect the database will be very useful, because due to the very irregular flowering of the Dipterocarpaceae, flowers and fruits are usually unavailable, and even if they are present, they are found high in the tree.

Description: A pollen morphological survey of the genus Guioa is presented. Based on a study of the harmomegathy in relation to morphological series, evolutionary trends are postulated: 1. wide ectoapertures → narrow ectoapertures 2. grain parasyncolporate → grain colporate 3. grain parasyncolporate → grain syncolporate 4. ornamentation rugulate → ornamentation psilate-imperforate. It is suggested that the most ‘primitive’ species of Guioa occur in the southeastern part of the distribution area of the genus. Guioa can be subdivided into four poorly delimited pollen morphological groups. Its affinities to other genera in the Cupanieae are briefly discussed. Pollen of the most ‘primitive’ group is similar to that of several ‘primitive’ genera (e.g. Arytera, Matayba, Molinaea, and Tina) in the tribe.

Description: The pollen morphology of all 11 species of the genus Mischocarpus is studied. All species possess basically the same syntricolpate pollen type. Transitions to the tricolpate type were observed rarely. Within the syntricolpate type, subtypes could be established. For a few species a rather wide range of variability in some characters is described. Pollen morphology correlates with macromorphology as well as with geography, thus supporting the results, based on macromorphological evidence, concerning infrageneric structure and relationships of Mischocarpus.

Description: A new monotypic genus from Cambodia is described. The genus is defined by a unique combination of characters and has distinct pollen features. The only species is Khmeriosicyos harmandii W.J. de Wilde & Duyfjes.

Description: A pollen-morphological survey of all four genera of the Stemonaceae at the light and electron microscope level is presented. Stemonaceae is a eurypalynous family. Stichoneuron pollen, up to now described as monosulcate, appears to be inaperturate. Pentastemona pollen is most deviating in Stemonaceae. Its sexine consists of elements that resemble Ubisch bodies very much. It shares several features with pollen of Peliosanthes (Convallariaceae) and Trillium (Trilliaceae). However, the closest relatives of Pentastemona could not be traced with the available pollen-morphological evidence.

Description: A new monotypic genus from New Guinea is described. Its pollen matches that of the Cucurbitoieae–Melothrieae, except for its small size.

Description: Mischocarpus Blume, Bijdr. (1825) 238, nom. cons.; Rumphia 3 (1849) 166; Radlk., Pfl. R. Heft 98 (1933) 1288—1310. — Cupania § Mischocarpus Miq., Fl. Ind. Bat. I, 2 (1859) 566. — Type: M. sundaicus Bl. Pedicellia Lour., Fl. Coch. (1790) 655, nom. rejic. (see under dubious names). — Type: P. oppositifolia Lour. Mischocodon Radlk., Bot. jahrb. 50 (1913) 79; Pfl. R. Heft 98 (1933) 1327—1328. — Type: M. reticulatus Radlk. Shrubs or, sometimes large, trees, sometimes with a slender unbranched stem. Buttresses sometimes present (M. largifolius). Indumentum rather dense to sometimes very sparse, consisting of mostly appressed, short to long, brownish to ferruginous hairs; no glandular scales. Twigs brownish to reddish-brown to greyish. Axillary buds just above or, mostly in ramiflorous species, up to 6 mm above the base of the petiole. Leaves spirally arranged, paripinnate, the leaflets accrescent in size towards the top, 1—6-jugate, without stipules; petiole ± semi-terete, sometimes dorsiventrally flattened. Leaflets alternate to subopposite, petioluled, ratio 1.5—5(—8), widest below, in, or above the middle, sometimes curved downwards (in the herbarium showing a folded base and apex and sometimes an undulate or folded margin), sometimes bullate, pergamentaceous to coriaceous, when dry above mostly greyish-green, sometimes smooth and shiny, beneath mostly brownish-green, not papillose, above glabrous or hairy on midrib and nerves, beneath glabrous or hairy mainly on midrib, nerves and along the margin, between the nerves very sparsely appressedly short-hairy, often glabrescent; domatia often present in axils of main nerves; base equalsided, rarely slightly oblique, rounded or acute to blunt, decurrent; margin entire, flat or sometimes revolute; apex rounded or acute to blunt, mostly shortly mucronate, or ± acuminate or retuse or rarely emarginate; acumen rounded or acute, mostly slightly retuse; midrib above prominent to sunken, rounded or angular, sometimes carinate, beneath prominent, in cross-section about semi-circular, sometimes nearly completely circular ( M. grandissimus), slightly angular to the base; nerves not or sometimes indistinctly connected in the lower 0.5—0.75, in the upper part connected, about straight to rather strongly curved; intercalated veins present, sometimes indistinct; veins and veinlets nearly always forming a very regular reticulate pattern, dense; nerves, veins, and veinlets ± prominent on both faces, beneath stronger so than above, veinlets inconspicuous beneath. Inflorescences pseudoterminal, axillary, and ramiflorous (probably also cauliflorous in a few species), composed of one or more thyrsoid axes, these nearly always branched, erect to spreading, mostly slightly grooved, with stalked or sometimes sessile cymules, glabrous to densely hairy; cymules 1—7(—10)-flowered; pedicels 1—3(—5) mm; bracts triangular to lanceolate, sometimes subulate, outside glabrous or hairy, inside mostly glabrous. Flowers unisexual, probably mostly monoecious (dioecious in M. reticulatus?). Calyx spreading or cup-shaped, early expanding, 5 (rarely 6)-merous, connate for up to 65%, membranaceous to subcoriaceous, sometimes somewhat fleshy; lobes subequal, sometimes slightly imbricate at the base, triangular to ovate, outside variably hairy, inside glabrous or hairy, often only a row of hairs near the base sometimes hidden by the disk; apex acute, sometimes acuminate. Petals 0—5, from minute up to slightly longer than the calyx, apert, unguiculate or not, variably hairy, mostly on claw, base of plate, and auricles; plate elliptic to ovate, sometimes triangular or rhomboid; apex sometimes lobed; 2 auricles or scales mostly present, without crest. Disk complete or sometimes interrupted, annular or cup-shaped, sometimes surrounding base of stamens and confluent with pistil, glabrous or short-hairy. Stamens (5—)8(—9), exserted (sometimes rather long); filament thread-like, glabrous or appressedly to patent-hairy, more densely so to the base; anther basifixed, base and apex emarginate; connective sometimes with a lighter coloured wart at the top; thecae about ellipsoid, glabrous or sparsely hairy, smooth or papillose (most distinct when not yet exserted), dehiscence lateral or latero-introrse. Pistil 3-(rarely 2- or 4-) celled, glabrous or appressedly short-bairy; ovary stiped or almost sessile, about ellipsoid- to obovoid-triangular; style apical, shorter to slightly longer than ovary, the upper part either split in 3 ± recurved stigmatic lobes or almost undivided, bearing 3 stigmatic lines (M. exangulatus); ovules 1 per cell, apotropous, anatropous, ascending, base collar-like, surrounding micropyle and funiculus. Pistillode small, densely hairy to subglabrous. Infructescences sometimes with accrescent axes and pedicels; calyx present, sometimes accrescent, mostly glabrescent; disk present, not accrescent. Fruit nearly always distinctly stiped (in M. paradoxus only up to 1 mm), not lobed, the cells about equally developed but the ovules abortive in (1) 2 cells, loculicidal, up to 3.5 cm long, reddish when ripe, glabrous or hairy; stipe empty, 3-celled, cylindrical near the base, distally becoming triangular; seed bearing part triangular to rounded in cross-section, with elliptic to obovate valves, apiculate; valves thin to almost woody, mostly shrivelled after dehiscence; pericarp slightly fleshy; endocarp sclerenchymatic, either complete, lining valves (except for M. exangulatus also lining stipe) and distal parts of the septa, or incomplete, only along the sutures (see fig. 1g and 1h); septa membranaceous, at least in the proximal half; endocarp and septa glabrous or variably hairy. Seed sometimes pendulous by the appendix of the arillode, globose to ellipsoid; hilum adaxial, basal; testa shining, chestnutbrown, finally (nearly) completely covered by a thin-fleshy, translucent, bluish or yellow to orange arillode which is attached around hilum and micropyle; arillode nearly always (except M. paradoxus) with an appendix abaxial of the hilum and micropyle, descending into the stipe; cotyledons equal or not, folded or not; suture between cotyledons either transverse and straight, or curved (see fig. 1e and 1f). Plumule glabrous or variably hairy (not constant within one species).

Description: Two main types may be distinguished within Alectryon pollen: the colporate type and the parasyncolporate type. These types are not clear-cut, but merge into each other through a complete series of intermediate forms. The colporate type has usually a colporate apertural system, a high P/E value (av. 0.97), a low A/E value (0.32), and striate to striate-rugulate ornamentation. The parasyncolporate type shows usually a parasyncolporate apertural system, a low P/E value (av. 0.76), a high A/E value (av. 0.46), and striate-rugulate to rugulate ornamentation. In addition, there is some difference in endoaperture and nexine morphology, and the relative length of the peripheral columellae of a mesocolpium. An endoaperture in a colporate grain often shows acute or acuminate lateral sides or a fastigium; these characters were never observed in parasyncolporate grains. Colporate pollen has usually a less regular endexine/foot layer boundary than parasyncolporate pollen. Colporate pollen may have relatively short columellae or no distinguishable columellae at all along the colpi, whereas in parasyncolporate pollen the peripheral columellae are always relatively long.

Description: Consequently upon a revision of Mischocarpus (Van der Ham, 1977a), a detailed study has been made of several characters in Arytera in order to get a better understanding of the delimitation of the two genera mutually. The differences between Mischocarpus and Arytera given by Radlkofer (1931) in his key are vague and can only be used when fruiting material is available. However, several species in Arytera were described by him and others on flowering material only. Two species of Mischocarpus could be connected with species of Arytera. One species of Arytera appeared to be the same as Mischocarpus exangulatus. M. exangulatus has, besides typical Mischocarpus characters, several features unique in Mischocarpus but more regularly occurring in Arytera. Radlkofer distinguished 4 sections with 24 species. A few more species were described afterwards but were not placed in a section. When searching for new characters on which to base a better delimitation against Mischocarpus, variation in several characters of Arytera turned out to be rather wide for a genus within the Cupanieae. Moreover, these variations appeared to be discontinuous. With help of a few characters, groups of species could be formed which are more natural and better based than the sections made by Radlkofer. Several species or groups of species turned out to be wrongly placed or at least dubious in Arytera. Even the naturalness of Arytera as provisionally accepted here can be questioned. The material studied mainly comes fom L and M (types of Radlkofer). Material of nearly all species was available.