Taiwania 62(1): 67‒74, 2017 DOI: 10.6165/tai.2017.62.67 Diversity in fruit and seed characters of Chamaelirium and Chionographis (Melanthiaceae) Noriyuki TANAKA 98-11 Otsuka, Hachioji, Tokyo, 192-0352 Japan. Email: [email protected] (Manuscript received 22 August 2016; accepted 26 January 2017; online published 22 February 2017) ABSTRACT: Phenotypic characters of fruits and seeds of two closely allied genera Chamaelirium and Chionographis (Melanthiaceae) are reexamined. The results show that the two genera differ mainly in the number of ovules per locule, the shape of seeds, and the arrangement of seeds within the locule and of a seed body within the testa. Evidence also shows that in Chionographis a Chinese species (C. chinensis) significantly differ from three species from Japan and Korea (e.g. C. japonica) chiefly by the seeds acutely beaked proximally and in the narrowly obovoid, proximally cuneate fruits (capsules) that ripen in May to June (vs. autumn) and have a carpo-gynophore and locules mutually free, acute, and indehiscent in the proximal part. Data obtained is discussed from taxonomical and evolutionary aspects. KEY WORDS: Carpo-gynophore, Chamaelirium, Chionographis, Fruits, Diversity, Evolution, Melanthiaceae, Seeds, Taxonomy. INTRODUCTION length, and accordingly, they are taxonomically inseparable in this respect. Chionographis Maxim. (Melanthiaceae) is a genus of As for their fruits and seeds, the two genera approximately eight species distributed in Vietnam, Laos, reportedly differ in the number of ovules per locule and China, Japan and Korea (Tanaka, 2016a, b; Wu, 2016). It in the shape of seeds, as aforementioned. Previous is regarded as most closely allied to a monotypic genus reports also indicate that the size of capsules and the Chamaelirium Willd. of eastern North America (Miquel, arrangement of a seed body within the testa differ 1866, 1867; Maximowicz, 1867; Hara, 1968; Kawano, between the two genera (Yatabe (1893) for 1976; Dahlgren et al., 1985; Tanaka 1985, 2003; Takhtajan, Chionographis; Gleason (1952) for Chamaelirium; 1997, 2009; Utech, 2002; Wu et al., 2016). Recent Hara (1968) for Chionographis). Further, Hara (1968) analyses of the matK gene region of chloroplast DNA in reported that the capsules and seeds of Chionographis many genera of monocots support this view, showing that are different in shape between species from China and the two genera are sister groups in the monophyletic clade species from Japan and Korea. Thus the information of the family Melanthiaceae (Fuse and Tamura, 2000). hitherto available implies that the two genera are not a The closest group of the two genera was supposed to be little diversified in fruit and seed characters. Helonias L. and its closely allied genera (e.g. Tanaka, For the elucidation of taxonomic and evolutionary 1997; Tamura, 1998), which is also later supported by aspects of the two genera, it is necessary to accumulate chloroplast DNA sequence data (Fuse and Tamura, 2000). sufficient data on various characters. Among others, Chionographis is distinguished from Chamaelirium having ample data on their fruits and seeds is crucial for usually by its zygomorphic flowers (vs. actinomorphic achieving this purpose, because these characters are flowers), unequal tepals (vs. equal tepals), fewer ovules markedly diversified in them, according to previous per locule (2 vs. 6–12), fusiform seeds tailed at the ends reports. However, our knowledge on these characters (vs. oblong-elliptic seeds winged around), and still seems insufficient. For instance, we have no hermaphroditic or gynodioecious populations (vs. information on the arrangement of ovules (seeds) dioecious populations) (Maximowicz, 1867; Baker, within the locule in Chamaelirium. To complement this 1879; Bentham, 1883; Baillon, 1894; Krause, 1930; insufficiency, the present work was undertaken. Hara, 1968; Tanaka, 1985, 2003, 2013, 2016a, b; Maki, In this study, fruits and seeds of the two genera are 1993; Tamura, 1998; Utech, 2002; Wu et al., 2016). closely reexamined with the aim of clarifying their Regarding their floral morphology, recent studies diversity. The results of comparative observations on revealed that two species of Chionographis, C. them will be described here with illustrations, and shiwandashanensis Y.F. Huang et R.H. Jiang (Huang et discussed from taxonomical and evolutionary aspects. al., 2011) from southern China and C. actinomorpha Aver. et N. Tanaka (Averyanov and Tanaka, 2014) from MATERIALS AND METHODS Vietnam and Laos, have actinomorphic flowers with six equal tepals. This finding indicates that the two genera Plants examined in this study are Chamaelirium share the same floral trait as to symmetry and tepal luteum (L.) A. Gray (distributed in U.S.A.) and four 67 Taiwania Vol. 62, No. 1 Table 1. Comparison of several characteristics (other than those of ovary-fruit and ovule-seed) in species of Chamaelirium and Chionographis. Character Cha. luteum Chi. hisauchiana Chi. japonica Chi. koidzumiana Chi. chinensis (Range: USA) (Japan) (Japan, Korea) (Japan) (China) Inflorescence rachis Color 1) white (male) or white white green white (sexual type) green (female) (all sexual types) (all sexual types) (all sexual types)2) (all sexual types) Flower Direction1) ascending or horizontal horizontal or sl. sl. descending sl. descending sl. descending descending Symmetry actinomophic zygomorphic zygomorphic zygomorphic zygomorphic Base shortly pedicellate sessile sessile sessile sessile Tepal Lower tepal as long as upper shorter than c.1/2 vestigial or vestigial or shorter than c. 2/3 (length) tepal of upper tepal lacking lacking of upper tepal Shape spatulate spatulate spatulate filiform spatulate Anther bilocular bilocular bilocular unilocular bilocular 1) At early and middle stages of flowering; 2) Other than female which is not found; Abbreviation: sl., slightly. species of Chionographis, C. chinensis Krause (including RESULTS C. merrilliana Hara; China), C. hisauchiana (Okuyama) N. Tanaka (Japan), C. koidzumiana Ohwi (Japan), and C. Several characters of flowers and inflorescences are japonica (Willd.) Maxim. (Japan and Korea). compared among five species of Chamaelirium and Living plants of Chamaelirium were introduced from Chionographis in Table 1. As evident from this table, U.S.A. through a botanical garden or nurseries, and those they are variable among the species, and the respective of Chionographis in Japan were collected myself in their species are highly distinctive for their own features. habitats. They were/are cultivated at Hachioji, Tokyo, and The results of observations on their fruits, seeds and studied from morphological and phenological aspects. relevant floral characters (such as ovaries and ovules) Dried herbarium specimens kept at A, BM, GH, K, KYO, are described below. Those characters which show KANA, MAK, TI, TNS, UC and my own herbarium were variation among the species are outlined in Table 2. also examined to grasp the range of variation in characters here concerned. Several representative specimens 1. Basic features in flowers, fruits and seeds of examined are cited at the end of this text. Obsevations and Chamaelirium and Chionographis. measurements of characters were made under a zoom All the species examined has a tricarpellary pistil stereomicroscope equipped with an eyepiece micrometer. with a superior, syncarpous (Chamaelirium and Descriptions of characters are based on both living plants Chionographis excluding C. chinensis) or semicarpous and herbarium specimens except C. chinensis of which the (C. chinensis) ovary, and three, free, linear or ligulate, living plants were unavailable. Drawings were made from ventrally stigmatic styles. The styles, tepals and materials in List 1. stamens are persistent in fruit (Fig. 4A). The ovaries develop into capsules that are antrorse, loculicidal and List 1. Sources of material used for drawing. trivalvate (Figs. 1–4). Their pedicels are short and Chamaelirium luteum antrorse in fruit (Figs. 1–3, 4A). L-1: U.S.A. West Virginia. Fruits harvested on 28 Sept. – Within an ovary, ovules are pendent from axile 13 Dec. 2008 by Noriyuki Tanaka (s.n.). placentae, nearly hemitropous (Chionographis) or L-2: U.S.A. Precise locality unknown. Fruits harvested on 19 Oct. 2015 by Noriyuki Tanaka (s.n.). intermediate between anatropous and hemitropous Chionographis chinensis (Chamaelirium), and have a negligibly short funicle at C-1: China. Guangdong. Tsengshing District, Naam Kwan the adaxial middle (Chionographis) or middle to Shan, 30 Apr. 1932, W. T. Tsang 20386 (UC). subdistal portion (Chamaelirium), a relatively large Chionographis japonica J-1: Japan. Toyama Pref., Uozu-shi, Kosuganuma, 19 July micropyle in the adaxial upper portion above the funicle, 1980, Noriyuki Tanaka s.n.; Infructescences and a raphe situated along the adaxial lower portion of harvested on 8 Nov. 2013 and 12 Nov. 2015 by the nucellus. These features of ovules, as to the Noriyuki Tanaka (s.n.). arrangement within an ovary and the relative position of a funicle, micropyle, raphe and nucellus, are more or less Terms “carpophore”, “gynophore” or “carpopodium” retained in mature seeds (Figs. 1–4). The body of a seed followed the respective definitions in Harris and Harris is (sub)ellipsoid, pale to medium brown, and clothed (1994). The term “carpo-gynophore” used in the present with a scarious testa (seed coat) (Figs. 1–4). A tiny, paper refers to an elongate axis of receptacle that not only narrrowly ellipsoid embryo is embedded in copious