Flora Malesiana ser. I, Vol. 11 (2) (1993) 227-351 Rosaceae C. Kalkman Leiden, The Netherlands) Gen. PL Gen. Flow. PI. 1 Rosaceae Juss., (1789) 196, nom. cons.; Hutch., (1964) 174-216; Vidal, Fl. Camb., Laos & Vietnam 6 (1968) 1-210 (excl. Rubus); Nguyen Van Thuan,ibid. 7 (1968) 1-83 (Rubus); Vidal, Fl. Thailand2 (1970) 31-74 (Rubus by Nguyen Van Thuan); Tirvengadum, Fl. Ceylon 3 (1981) 328-378. — Type genus: Rosa L. sometimes Woody or herbaceous plants. Leaves usually spirally arranged, distichous, rarely opposite (not in Malesia), simple or compound. Stipules on the twig or on the base of the petiole, free or adnateto petiole, rarely absent Inflorescences various. Flowers usu- ally bisexual and actinomorphic. Hypanthium (‘calyx tube’ of many authors) usually very tubular the distinct, from saucer-shaped to or campanulate, sepals, petals, and stamens inserted on its rim, its inside usually lined by a nectariferous disk. Sepals usually 5, free, in some tribes an epicalyx also present. Petals usually 5, free, from large and showy to small and not or hardly distinct from sepals, in some genera/species absent. Stamens usually numerous, but sometimes the number distinctly related to the number of perianth leaves, filaments anthers 1 free free, bilocular, dehiscing longitudinally. Pistil(s) to many, or variously connate with each other and/or with the hypanthium, ovary(ies) superior to several inferior, style(s) present, ovule(s) 1 to (often 2) per locule, anatropous, ascending or pendulous. Fruits various, fleshy or dry, dehiscent or not. Seed(s) 1 to several, with- out or with scanty endosperm, cotyledons fleshy or flat. Distribution — A large family with worldwidedistribution, including more than 3000 species in c. 100 genera. Almost all genera which are represented in Malesia have their ac- tual ofdistributionin centre temperate to subtropical regions on the Northern Hemisphere. Some of those are large or medium large genera with only one or two species in Malesia (Rosa, Alchemilla, Eriobotrya), others have a more or less distinct sub-centre in the Male- sian Prunus, is region ( Rubus, Potentilla). Exceptional Acaena, a genus with a Southern Hemisphere distribution, of which one species also occurs in New Guinea. Kalkman [Bot. J. Linn. Soc. 98 (1988) 37-59] postulated a Southern (Gondwanan) origin for the family and migration via three routes. Malesia in this view was reached mainly from the Asian continent (Laurasia), which in turn was reached by way of South, Central, and North America and via Beringia. Partly maybe the continent was also reached from Gondwana the Indian 'raft' A third directly by transport on (Alchemillal). route was via Australia (Acaena). Most authors, however, favour a Laurasian origin for the family. Habitat— The majority of Malesian Rosaceae belongs to the mountainflora and occurs only above 1000it 1500 m altitude, in montane forest types, thickets or (sub)alpine grass- the Rubus lands. Only in genus (a dozen species) and in Prunus (more than 20 species) an appreciable proportion ofthe species are (also) found in the lowlands. 227 228 Flora Malesiana ser. I, Vol. 11 (2) (1993) Ecology — As is true for almost all Malesian higher plant families, no autecological research has been carried out for members ofRosaceae. From the habitats where the spe- cies have been collected, some superficial conclusions may be drawn about preferences or the tolerances for light, temperatureand soil conditions and wherever possible, paragraphs this kind of information. on Habitat and Ecology contain Pollinationis undoubtedly normally by (unspecified) insects, as in the European rela- tives. Apart from the formationof a good quantity of pollen and the secretion of nectar by in the flowers related kinds the disc, there are no specializations to pollination by specific of insects. Only for Acaena wind-pollination might be inferred, but experimental orobser- labels. vational evidence is lacking in literature or on animals. foundin For dispersal most Rosaceae rely heavily on Exceptions are genera with multi-seeded follicles with dry seeds (in Malesia only Neillia) where dispersal is by of the Potentilla that have the ballistochory. The same is true for most species dry achenes and Some have in the cups formedby the hypanthium, sepals epicalyx. genera dry achenes, imbedded in or surrounded by a fleshy spurious fruit (Rosa and also the not indigenous the the functions Fragaria and Potentillaindica). In these cases hypanthium, resp. torus as the attractant for endozoochory by snails, birds, or other animals. Many Rosaceae of dif- ferent tribes have gone the way to fruits with a fleshy or juicy layer in their walls (drupes, either single or as collective, or pomes) and obviously these are also endozoochorous. Epizoochory is only exercised by Acaena and Agrimonia which possess spines on their hypanthium in which the fruit is included. Taxonomy and Phylogeny — In modern systems the Neuradaceae and the Chryso- balanaceae [for the latter, see Flora Malesiana 1,10 (1989) 635-678] are mostly not in- cluded inRosaceae, as in earlierclassifications, but recognized as families in their own right. In the family Rosaceae as implied in the previous paragraph usually four subfamilies are distinguished: Spiraeoideae, Rosoideae, Maloideae(Pomoideae), and Prunoideae (Amygdaloideae). The last-mentioned two groups are undoubtedly two end-branches in the phylogenetic tree, well recognizable, distinct, and natural (holophyletic) taxa. This cannot be said for the two other subfamilies. The group Spiraeoideae contains the genera follicles is with dry, dehiscent fruits. Dehiscent a plesiomorphic (primitive) character in the this character shouldbetter included family and the generapossessing be in a taxon with the generathat have been derived from them. Considering the likeness of the flowers of some Spiraeoideae and those of some Maloideae like Cotoneaster and Pyracantha, I would be inclined the Maloideaewith least of to enlarge subfamily at part the Spiraeoid genera. The Rosoideae are quite heterogeneous and they have probably to be unitedwithother, branch, in which 'Spiraeoid', genera to form another holophyletic maybe some subdivision is possible. A phylogenetic analysis, only considering morphological characters [Kalkman, Bot. J. Linn. Soc. 98 (1988) 37-59] was not successful and should be repeated with an augmented set of characters, also anatomical and chemical ones. Awaiting this, the recognition of the four classical subfamiliesis hardly justified. Kalkman Rosaceae 229 divided the The next lower levelof classification was used by Hutchinson, I.e., who tribes. Some of these others contain family in some twenty are heterogeneous, some only 'difficult' that have found with their rela- one or two genera not yet a good place nearest tives in the phylogenetical sense. The firm core of a tribal classification consists of the following tribes: S Spiraeeae (see p. 244) S Neillieae (see p. 245) S Gillenieae(maybe to be split into two tribes) (not in Malesia) R Rubeae (see p. 247) Potentilleae R (see p. 285) R Dryadeae (probably to be divided into two tribes) (not in Malesia) R Poterieae (see p. 297) R Alchemilleae (usually includedin Potentilleaeor Poterieae) (see p. 301) R Roseae (see p. 303) M Maleae (Pomeae) (see p. 306) P Pruneae (including Osmaronia?) (see p. 319) in the classical = M = Maloi- S = tribes belonging to Spiraeoideae sense; R Rosoideae; deae; P = Prunoideae. have found natural in of the eleven thirteen The following genera not a place one (or after dividing two of them) tribes mentionedabove: in Hutchinson's classification, a rather the generacomposing the tribeQuillajeae hetero- geneous assemblage of Spiraeoid problem cases: Quillaja, Kageneckia, Exochorda, Lindleya, Vauquelinia, Lyonothamnus; a number of lone generaof uncertain disposition as to tribe and often also subfamily: Holodiscus, Rhodotypos, Kerria, Neviusia, Cercocarpus, Coleogyne, Filipendula, Potaninia, Adenostoma. None of the genera mentionedabove occur in Malesia. Morphology — As apparent from the family description, there is variation in many characters of and fruits. The of leaves, flowers, presence a well-developed hypanthium, a probably axial outgrowth from the top of the pedicel surrounding the pistil(s), is about the is all The elaborationof this only character that common to Rosaceae. hypanthium causes much of the variation in flowers and fruits. The plesiomorphic (original) situation is still present in Spiraeoid genera that have a small number (up to 5) multi-ovulateovaries on the bottom of a cupular hypanthium, the ovaries developing into ventrally dehiscent, dry- walled follicles containing several seeds. Adnation of the ovaries to the inside of the hypanthium, accompanied by a more or less complete fusion of the ovaries with each other, creates the possibility for the evolu- tion of the fleshy, (semi-)inferior fruits that are typical for Maloideae. In this group the exocarp of the inferior fruit is certainly hypanthial, the endocarp (membranous to woody) is certainly carpellary, the more or less fleshy mesocarp may be either or both. In the descriptions in this treatment the terms exocarp, mesocarp, and endocarp are used in 230 Flora Malesiana ser.l, Vol. 11 (2) (1993) their topographical sense, for superior as well as inferior fruits and thus not implying a carpellary origin. Anotherline ofevolution is the change of dry, multi-seeded follicles into dry, 1-seeded fruitwall and become are achenes, that later may develop a fleshy drupaceous. Examples Rubus