Description: For the identification of a flowering plant the first step usually is to discover to which family it belongs. With some experience, the families commonly encountered in one’s area of interest are soon known, but when dealing with specimens from other places, notably those from the vast and rich subtropics and tropics, there is much less certainty. The pertinent literature is often not readily available as it is often found only in expensive, rare or obscure books, or journals, present only in a few specialized institutes. Basically only a few keys to the families of flowering plants of the world have ever been produced, the best known of which at present is Hutchinson’s Key to the families of flowering plants (1973); less well-known are Lemée’s Tableau analytique des genres monocotylédones (1941) (incl. Gymnosperms) and his Tableau analytique des genres dicotylédones (1943), and Hansen and Rahn’s Determination of Angiosperm families by means of a punched-card system (Dansk Bot. Ark. 26, 1969, with additions and corrections in Bot. Tidsskr. 67, 1972, 152-153, and Ibid. 74 1979, 177-178). Of note also are Davies and Cullen’s The identification of flowering plant families, 2nd ed. (1979), which, however, deals only with the families native or cultivated in North Temperate regions, and Joly’s Chaves de identifição das famílias de plantas vasculares que ocorrem no Brasil, 3rd ed. (1977), which may be useful in other tropical areas too. There are a number of excellent keys prepared by an Austrian, Franz Thonner (1863-1928), which deal either with European genera (1901, 1903, 1918), or African ones (1908, 1913, 1915), or with all families of the world (1891, 1895, 1917). Some of these have apparently been completely overlooked, others have been known only to a few, and then sometimes served as a base for keys of their own, thereby again influencing keys by others (see Derived works).

Description: For the identification of a flowering plant the first step usually is to discover to which family it belongs. With some experience, the families commonly encountered in one\xe2\x80\x99s area of interest are soon known, but when dealing with specimens from other places, notably those from the vast and rich subtropics and tropics, there is much less certainty. The pertinent literature is often not readily available as it is often found only in expensive, rare or obscure books, or journals, present only in a few specialized institutes. Basically only a few keys to the families of flowering plants of the world have ever been produced, the best known of which at present is Hutchinson\xe2\x80\x99s Key to the families of flowering plants (1973); less well-known are Lem\xc3\xa9e\xe2\x80\x99s Tableau analytique des genres monocotyl\xc3\xa9dones (1941) (incl. Gymnosperms) and his Tableau analytique des genres dicotyl\xc3\xa9dones (1943), and Hansen and Rahn\xe2\x80\x99s Determination of Angiosperm families by means of a punched-card system (Dansk Bot. Ark. 26, 1969, with additions and corrections in Bot. Tidsskr. 67, 1972, 152-153, and Ibid. 74 1979, 177-178). Of note also are Davies and Cullen\xe2\x80\x99s The identification of flowering plant families, 2nd ed. (1979), which, however, deals only with the families native or cultivated in North Temperate regions, and Joly\xe2\x80\x99s Chaves de identifi\xc3\xa7\xc3\xa3o das fam\xc3\xadlias de plantas vasculares que ocorrem no Brasil, 3rd ed. (1977), which may be useful in other tropical areas too.\nThere are a number of excellent keys prepared by an Austrian, Franz Thonner (1863-1928), which deal either with European genera (1901, 1903, 1918), or African ones (1908, 1913, 1915), or with all families of the world (1891, 1895, 1917). Some of these have apparently been completely overlooked, others have been known only to a few, and then sometimes served as a base for keys of their own, thereby again influencing keys by others (see Derived works).

Description: Commercially available tree altimeters are expensive and heavy, and my personal experience with these instruments is thus minimal. During my last expedition I only used it now and then in the base camp to correct my \xe2\x80\x99feeling for estimation\xe2\x80\x99. I have little doubt that colleagues will recognize these feelings. After my return I regretted this attitude to some extent and tried to design a cheap and light alternative device. It is drawn on the next page, and easy to construct: Make a copy of the drawing. Photocopies are generally not exact enough, causing differences to 5 m in this scheme, due to barrel- and cushionshaped distortion by the lens. I advise to copy the drawing by hand on transparent paper. Glue this copy (preferably with epoxy-resin to make it waterproof) on hardboard (plexiglass, thin aluminium). Fix a water-level parallel to the horizontal line (which indicates c. 1.70 m eye-level!).\nAttach a transparent ruler with a thin but distinct straight line. This ruler is attached with a (nylon) bolt and nut (the latter fixed with cyano-acrylate, e.g. Loctite) in order to move the ruler to reach the necessary angle and to keep it in a fixed position easily. It needs some training to keep the righthand eye on the water-level (a small mirror may help here), the accuracy is sufficient when one sees the air-bubble moving or trembling. A much more severe factor causing inaccuracy is the impossibility to estimate in larger trees where the actual summit is hidden behind the crown. When impossible to locate, one can use the rule of thumb, that the actual summit is behind a point about halfway the base and the edge of the crown. An attached string of e.g. 20 metres facilitates to fix the horizontal distance. From the scale it is evident that one should not try to measure a 50 m tall tree from 20 m distance, 40 m is more accurate. The exactness of the device is mainly dependent on the length of the ruler, 25-30 cm is needed. Before fixing the water-level definitively, one should gauge its position by means of a tree or other vertical object (flagpole) of known height.

Description: The differentiating characters of Duabanga grandiflora (Roxb. ex DC.) Walp., D. moluccana Bl., and D. taylorii Jayaweera are given. Most characters of D. taylorii appear to be intermediate between those of the other two species; a few characters represent combinations of those of the two other species; one character is not shared by the other species. From this evidence it is supposed that D. taylorii is a hybrid. This suggestion is sustained by the history of the specimens on which D. taylorii is based. An attempt to count chromosomes of D. taylorii and D. grandiflora failed, probably due to the unsuitability of the fixative for this purpose.

Description: Name: Eurya Thunb., Nova Genera Plantarum (1783) 68.\nFamily: Theaceae.

Description: A method, based on samples taken at random is described. It is stressed that the obtained frequency scores directly correlate with cover percentages. When used in gradient and/or mozaic vegetations the results obtained are comparable to those of homogenous vegetations.

Description: Seeds of all specimens of Montiafontana L. from several herbaria in the Netherlands were studied scanning electron microscopically. Four main seed types could be recognised (fig. 1,2), corresponding with the types often used for dividing the M. fontana complex in species, subspecies or varieties. These main types are connected by intermediates and together they form a series of gradual variation. No other characters could be found that show a correlation with the seed types. Hence the authors refrain from a formal infraspecific subdivision of M. fontana.

Description: Portulaca advena Reichg. & Von Poellnitz (1939), based on adventive specimens collected near Erp, prov. N.-Brabant, Netherlands, and afterwards cultivated in a garden at Nijmegen, appears to be identical with the South American P. papulosa Schldl. (1853). The adventive species of Portulaca found in the Netherlands can be distinguished as follows: 1. Calyx-segments distinctly keeled. Leaves flat, obovate to spathulate, with axillary hairs 0.1\xe2\x80\x940.8 mm long ............................. P. oleracea L. 1\xe2\x80\x99. Calyx-segments not keeled. Leaves not flat but thick, linear to obovate, with axillary hairs c. 2\xe2\x80\x9415 mm long. 2. Leaves (4\xe2\x80\x94)7\xe2\x80\x9418 mm long. Corolla violet. Seeds bluish grey. ..... P. pilosa L. 2\xe2\x80\x99. Leaves 2\xe2\x80\x947 mm long. Corolla yellow. Seeds brown to black. .. P. papulosa Schldl.

Description: In the introduction a brief historical review is given of the more important earlier treatment of the genus. In chapter 2, covering morphological observations, I have also inserted remarks on the systematic value of certain features. The axillary (and in sect. Neossia, nodal) hairs have often been interpreted as representing stipules. I have tried to advance arguments in order to show that their stipular homology is most unlikely. It is confirmed that there is no essential difference between the morphological structure of the inflorescence and that of the vegetative portion of the plant. There is no unanimity of opinion about the interpretation of the 2-whorled perianth; the outer series is often accepted to be of a bracteal nature. Von Poellnitz refers to the outer whorl as \xe2\x80\x98Involukralbl\xc3\xa4tter\xe2\x80\x99, Legrand names them \xe2\x80\x98pseudosepalos\xe2\x80\x99. However, the fact that in subg. Portulaca, with flowers in capituli, the whorls are inserted at the same height on the receptacle which is adnate to the basal part of the ovary, and the fact that below the receptacle there are generally two true bracts, make it almost certain that such assemblage is a contracted triad, with one developed flower and 2 \xe2\x80\x98bracteoles\xe2\x80\x99. This cymose nature is further sustained by the species of subg. Portulacella in which true cymes occur. In chapter 3 it is argued that the present wide distribution of several species, e.g. P. pilosa, P. quadrifida, and P. oleracea, is mainly due to man, by his transport and cultivation. Such species behave often as ruderals and adventives beyond their original country. Of some of these the genuine native country is for these reasons even unknown or very uncertain, e.g. that of the diploid P. oleracea; its cultivated strain is hexaploid but this is also found as a ruderal and adventive. P. pilosa s. l. may be originally of Australian origin, judging from the geographical area of its nearest allies and the very large degree of variability it exhibits in Australia. Self-pollination is obviously the rule in Portulaca as well as in Talinum, another genus of the same family; this may even be prevalent in the entire family. This implies, and explains, a profuse occurrence of more or less pure lines (local populations or races) in nature which keep constant in details (e.g. the sculpture of the testa). For this reason, not a few of these have been distinguished as (micro) species by former authors. Some of these characters are more conspicuous in the field than in the herbarium. For example, I have grown two of such lines of Talinum paniculatum which throughout their range differ (in living state) constantly in the following three minor characters: testa minutely tubercled or smooth, panicles narrowed or not, fruits red or yellowish. Such characters would seem to be determined merely by a few genes, and do not or hardly deserve systematical recognition as formal taxa. They are just on the border of herbarium taxonomy, and can only be solved, as to their genetical basis, by experimental taxonomie work. Only when more and clearer characters occur combined in complexes I have accepted these in a formal taxonomie hierarchy, e.g. in P. pilosa. On the whole I have felt induced to be rather conservative in accepting good species, but many are reduced to synonymy or to infraspecific rank. In chapter 4 the subdivision of the genus is discussed. It appeared that those of von Poellnitz (1934) and (to a lesser degree) Legrand (1953, 1958) are unsatisfactory. I have framed a new, more simplified, subdivision reflecting my ideas. Some taxa could not well be understood and have been referred to under the genus.\nFrom the morphology and taxonomy it is concluded that the ancestral lineage of the genus is in Australia, which fits in with the general geographical configuration of the family which is predominantly a southern hemisphere group. Chapter 5 contains some notes on typification, which has been effected as much as possible, mainly by lectotypification. Unfortunately, some types proved to be untraceable. The area covered in this account ranges from India eastwards through Indo-Australia as far as the Central Pacific. I have refrained from citing specimens examined. A list of these will be published separately as an Identification List.\nIn the systematic treatment full synonymy, descriptions, and keys are given to taxa, both species and infraspecific entities. Not all names could be placed, either by absence of types or lack of material. These are listed at the end; tentative suggestions are given to their proper identity. The number of species distinguished in Portulaca has varied enormously. Linnaeus had only 2 species, P. oleracea and P. pilosa; Index Kewensis lists c. 600 names. In this century von Poellnitz has described in his papers precursory to his monograph described many dozens of new species. For a large part he withdrew these again and sunk them into synonymy in his monograph of 1934, in which he accepted in all 104 species. Subsequently c. 30 new species were added by various authors. Legrand (1962) in his revision of the American species reduced quite a number of von Poellnitz\xe2\x80\x99s species, still maintaining 62 species for the New World. He distinguished, however, a large number of varieties reflecting the variability of these species. More than 50 of his species belong to subsect. Stellulato-tuberculatae, mainly comprising the P. pilosa complex. In my opinion this complex consists of only one compound species, in which I have distinguished 8 subspecies for Indo-Australia. In America P. pilosa is obviously still more variable. I estimate that the entire genus consists of not more than 15 good species, mainly in the Old World, viz. 4\xe2\x80\x945 in subg. Portulacella, 3(\xe2\x80\x945) in subg. Portulaca sect. Neossia, , 2(\xe2\x80\x947) in sect. Portulaca subsect. Portulaca, and possibly only 2 in sect. Portulaca subsect. Stellulato-tuberculatae. The two Linnean species, P. pilosa and P. oleracea, possess, in that sequence, the greatest variability. The generic name Meridiana Schrank is reduced to Trianthema L.

Description: In August 1972, Dr. W. J. J. O. de Wilde and his wife, Mrs. B. E. E. de Wilde-Duyfjes, collected on Mt. Bandahara in North Sumatra besides the already known Swertia piloglandulosa another, yet unknown Swertia which gave rise to this preliminary revision. This plant occurs together with S. piloglandulosa but inhabits a moister place in the mountain heath, viz. along a small streamlet, and it appeared to represent a miniature form of S. piloglandulosa. Besides, it had a further reduced number of ovules.\nIt may be worthwhile to point out first the difference between dwarf forms and miniature forms.