Systematic Botany (2000), 25(1): pp. 15-25 © Copyright 2000 by the American Society of Taxonomists Additional Chromosome Numbers of American

THOMAS F. DANIEL Department of Botany, California Academy of Sciences, Golden Gate Park, San Francisco, California 94118

Communicating Editor: Anita Cholewa

ABSTRACT. Original meiotic chromosome counts are presented for 39 in 15 genera of Acanthaceae from Belize, Costa Rica, Ecuador, Mexico, Panama, the United States, and Venezuela. These reports include the first counts for 20 species representing 10 genera of the family, including the first chromosome number documented for the . Counts for 15 species confirm numbers previously reported for them from different sources. New chromosome numbers are reported in two genera, (« = 17 in C. pectinata) and (n = 24 in /. galapagana). New chromosome numbers are also reported in two species of Justicia, J. comata {n = 28) and /. oerstedii (n = 11). Systematic implications of these chromosome numbers are addressed where appropriate.

The Acanthaceae are a pantropical family with 1990; Daniel and Chuang 1993), most of the more than 4,000 species in some 230 genera. Major studied here are from Mexico and Central America. concentrations of species occur in southeastern Previous studies of chromosome numbers of plants mainland Asia, insular Malesia, India, Madagascar, from this region have helped to reassess the taxo- tropical Africa, Brazil, Andean South America, and nomic status of some unispecific genera, suggest Mexico-Central America. Studies of phylogenetic relationships among genera, and establish probable relationships within the family are in their infancy. basic numbers for genera. As a result, putative relationships are usually based on Lindau's (1895) outdated but complete classifi- MATERIALS AND METHODS cation of the family or Bremekamp's (1965) im- Between 1982 and 1998, buds and herbarium proved but incomplete infrafamilial classification. vouchers of 60 species of Acanthaceae were collect- Like many other large and predominately tropical ed from their native habitats in various countries of families of flowering plants, the Acanthaceae re- the Western Hemisphere. Some plants were grown main poorly known cytologically. Based on the at the San Francisco Conservatory of from summaries of chromosome counts cited below, seeds collected in the field (indicated by "cv" or chromosome numbers have been determined for "gh" following the field collection number). Buds approximately 468 species (or less than 12% of total were collected from these plants in the greenhouse species) in the family. In addition, one or more and vouchers were made from the cultivated plants. counts are known for only 67 of the 228 genera of My collection of Justicia galapagana (Daniel s.n.cv) Acanthaceae (i.e., 29%) recognized in Brummitt was taken from a greenhouse-cultivated plant (1992). Counts have been determined for only a sin- grown from seed collected on Santa Cruz Island in gle species in 25 of these 67 genera. the Galapagos Islands (i.e., no collection was made During the past 20 years my research has fo- in the field). Floral buds for chromosome studies cused on Acanthaceae in North America and Cen- were fixed in absolute ethanokglacial acetic acid (3: tral America, a region in which about 500 species 1) for 24 hours and subsequently washed and are known to occur These species represent natural stored in ethanol (70%) until analyzed. Anthers occurrences of taxa for three of the four tradition- were macerated in ferric acetocarmine (1%) and ally recognized subfamilies of Acanthaceae (Lindau counts were made from microsporocytes in various 1895): , Mendoncioideae, and Nelson- stages of meiosis. Chromosomes were studied un- ioideae. Several species of the fourth subfamily, der oil immersion on a phase contract microscope Thunbergioideae, are naturalized in this region. at a magnification of lOOOx. Counts from at least This study is a further contribution toward provid- two cells were made for most collections and all ing basic cytological information on American counts were verified by at least two persons. Prep- Acanthaceae. As in several previous studies on arations from which counts were obtained were re- chromosomes of Acanthaceae (Daniel et al. 1984, corded with camera lucida drawings. Voucher spec-

15 16 SYSTEMATIC BOTANY [Volume 25

RESULTS

Chromosome numbers determined for 39 species representing 15 genera of Acanthaceae from Belize, Costa Rica, Ecuador, Mexico, Panama, the United States, and Venezuela are summarized in Table 1. a'7^ ' :'b J^ • ^ Based on the 60 species for which counts were at- tempted, this represents a success rate of about 10 um 65%. Typical problems encountered among those A bud samples for which counts were not obtained included: buds either too old or too young, clump- ing of chromosomes during meiosis, dark cytoplas- mic staining, and dark granules in the cytoplasm. In preparations from which counts were obtained pollen mother cells were observed to be particular- •^^• d •• ly large (varying in diameter from 43-200 |a,m) whereas the chromosomes they contain are rela- tively small (varying in length from 2.4-16 fxm at metaphase I).

DISCUSSION e *»^ f * • * > Counts that Confirm Previous Chromosome Numbers. Counts obtained for the following 15 species agree with some or all chromosome num- FIG. 1. Camera-lucida drawings of meiotic chromo- some preparations, a. Justicia oerstedii {Daniel et al. 6219), n bers previously reported for the same species from = 11 (metaphase I), b. tonduzii {Daniel et al. different sources: andersonii (agrees 8105), n = 14 (metaphase I), c. Justicia comata (Daniel & with Daniel et al. 1990), Aphelandra gigantiflora Almeda 6356), « = 28 (diakinesis I), d. Carlowrightia pectin- (agrees with Daniel and Chuang 1993), A. guerrer- ata {Daniel et al. 6846), n = 17 (metaphase I), e. Poilcilacan- ensis (agrees with Daniel and Chuang 1993, which thus macranthus {Daniel 6180gh), « = 14 (metaphase I), f. was based on cultivated progeny of this same num- Justicia galapagana {Daniel s.n.cv), « = 24 (metaphase I). ber), A. sinclairiana (agrees with Daniel in press and McDade 1984), gangeiica (see below), Ble- chum pyramidatum (= B. brmvnei; agrees with Daniel et al. 1984 and Grant 1955), Carlowrightia arizonica imens are deposited at CAS and the camera lucida (agrees with Daniel et al. 1984), C. hapalocarpa drawings are attached to the specimens. Drawings (agrees with Daniel 1983), C. parvifbra (agrees with of several critical preparations are reproduced here Daniel et al. 1984 and 1990), brachiata (Fig. 1). In the following discussion, all previously (agrees with and confirms Grant's approximate published chromosome counts are listed as n (ga- count of In = ca. 80 reported in 1955), J-Jolographis metic, haploid, meiotic) numbers irrespective of paluda (agrees with Daniel et al. 1990), Justicia be- whether they were originally reported as sporo- tónica (agrees with most previous counts; see Dan- phytic or gametophytic numbers. Voucher speci- iel and Chuang 1998), /. secunda (agrees with Daniel mens, if they exist, documenting previous counts et al. 1990), nudifbra (agrees with previous by other workers have not been examined. Previ- counts; see Daniel et al. 1990), and Tetratmrium oax- ously reported approximate counts have generally acanum (agrees with Daniel et al. 1990). been ignored unless they have been confirmed by Asystasia gangetica is widely distributed in the my studies. Paleotropics, naturalized in parts of the United The concept of basic chromosome numbers was States (e.g., Florida and Hawaii), and cultivated discussed by Rieger et al. (1976) and Dyer et al. throughout much of the world. It has often been (1970). In the discussion below, the basic number is studied by those counting chromosomes of Acan- typically postulated to be the only known haploid thaceae. A chromosome number of n = 26 has been number or the lowest known haploid number of a reported previously on eight occasions for A. gan- euploid series. getica (including A. coromandeliana Nees; Narayanan 2000] DANIEL: CHROMOSOMES OF ACANTHACEAE 17

1951; Grant 1955; Ellis 1962; Kaur 1965; Valsala chromosome numbers both for this species and genus Devi and Mathew 1982; Saggoo and Bir 1983,1986) than previously suspected. Such presumed intraspe- and is the most commonly reported number for the dfic dysploidy, though not common, is known in sev- species. Additional haploid numbers of 13 (Naray- eral other species of the family (see Daniel in press): anan 1951; Mangenot and Mangenot 1957, 1962; Elytraria imbricata (Vahl) Pers. (n = 11 and 12), Grap- Gadella 1977, 1982; Ugborogho and Adetula 1988), tophyllum pictum (L.) Griff (n = 20 and 21), Justicia 14 (Subramanian and Govindarajan 1980; Govin- ramosa (Oerst.) VA.W Graham (n = 11 and 12; re- darajan and Subramanian 1983), 22 (Narayanan ported as Siplionogbssa ramosa Oerst), and /. sessilis 1951), 24 (Narayanan 1951), and 25 (De 1966; Sarkar Jacq. {n = 22 and 23; reported as S. sessilis (Jacq.) et al. 1978) have also been reported for A. gangetica. Oerst.). Meiotic numbers of 13, 14, and 26 have also been My count of n = 28 for Justicia comata differs from reported for eight other species of the genus with two previous counts of M = 14 (Grant 1955; Meagh- 13 being most frequent (summarized by Federov er 1973) for this species. Likewise, my counts of n 1969; Ornduff 1967; Moore 1973; Goldblatt 1984, = 11 for /. oerstedii do not agree with the prior count 1985,1988; Goldblatt and Johnson 1991). I have nei- of M = 22 (Daniel et al. 1990) for the species. Eu- ther confirmed the identity of voucher specimens ploidy has been noted in several other species of (where they were noted to exist) for the various American Acanthaceae (e.g., virgata counts in Asystasia nor resolved the of (Harv. ex Benth. & Hook.) T.F Daniel; see Daniel et the 50 or more species in this genus; however, some al. 1984), and it appears to be present in both of preliminary conclusions can be drawn based on the these species as well. Based on numbers so far data available. A basic number of x = 13 is sug- known for these species, plants of /. oerstedii studied gested for the genus. Euploidy (e.g., the presence here would appear to be diploid whereas the col- of both n = 13 and M = 26 in both A. gangetica and lection of /. comata sampled would appear to be tet- A. dalzdliana Santapau) and presumed dysploidy raploid. both ascending and descending (e.g., counts of 14, First Chromosome Counts for Species. Chrom- 22, and 25 in A. gangetica) are present within spe- osome number determinations for the following 20 cies. Both polyploidy and presumed dysploidy also species represent the first counts for them: Aplielandra appear to have been important within the genus; tonduzii (n = 14), Blechum costaricense (n = 17), Diclip- for example, the chromosome number of A. tramn- tera iopus (n = 40), D. skutchii (n = 40), D. unguiculata corica Bedd., is reported to be M = 14 (Narayanan (n = ca. 40), ncmgaliciana (n = 15), Justicia 1951; presumably derived from ascending dysplo- angustibracteata (n = 14), J aurea (n = ca. 11), /. can- idy) and the chromosome number of A. mysurensis delariae (n = 14), J costaricana (n = 14), J galapagana in (Roth) T. Anders, is reported to be M = 26 (Kaur = 24), /. herpetacanthoides (n = 14), J isthmensis (n = 1965; a presumed polyploid). Once the genus and 14), J masiaca (n = 14), microphyllum (w = this species are better studied, it might be useful to 21), Poikilacanthus macranthus (n = 14), Pseiideranthe- seek correlations among morphology, chromosome mum floribundum (n = 21), P. sp (n = 21), Ruellia stan- numbers, and geography in A. gangetica. dbyi (n = 17), and pibsulum (n = 26). The New Chromosome Numbers for Species. Chrom- chromosome numbers of all of these species, except osome numbers obtained for three species (Carb- for Justicia galapanana and Poikilacanthus macranthus, wrightia pectinata, Justicia ccmata, and ]. oerstedii) differ agree with one or more previously reported counts from counts previously reported for them. A repre- for other species in their respective genera. Because sentative meiotic preparation for each of these species all other New World species of Dicliptera that have is illustrated in Fig. 1. The count of n = 17 for Car- been analyzed (11 species) have n = 40, the approx- lawrightia pectinata is somewhat perplexing. AU pre- imate count for D. unguiculata likely reflects a true vious coiints for both this species (Daniel et al. 1990) number of 40. Although a wide range of chromosome and for other species of Carbwrightia (12 species rep- numbers has been noted in Justicia (summarized be- resenting each of the five sections recognized by Dan- low), with n = 14 most commonly encountered, a iel in 1983; see summary of counts in Daniel et al. haploid number of 11 has been previously reported 1990; Daniel and Chuang 1993) are n = 18. In the in 12 species of the genus; the approximate count for material sampled here, several cells at various stages J aurea likely reflects a true number of 11. The count of meiosis all had n = 17. This suggests either an for J masiaca was reported by Daniel et al. (1990) as a individual (or population) of C. pectinata with an ab- count for Siplionogbssa longifbra (Torr) A. Gray. The errant chromosome number or a greater diversity in distinctions between these taxa were addressed by 18 SYSTEMATIC BOTANY [Volume 25

C5 LO ro 'vO O-i ^ en 'vO LO LO en -^.J«; '^en '^en '^rrj '^rrj rn LO s O^ 'O LO r^ s « c « « OO 'vO ro o í¿ 'vO '^ 1^ f^ ns -e Ts ns r-H '^ (N (N CO LO LO r-H tj 5 ^ ^ R 00 »o -~: wj -~: ---: -~: 'O t\ cs es CQ es• es• es- - '^ o es 'íjH es Qo '^ ío es h^ ts '^ ^ ^ '^ rrj Q (N 5 H-4 '^ -i-i '^ e ^ ^ CO t3 •s * •tí •^ "^ 1^ OO >a ^ ^ ^ ^ "í) ^ ^ "í) ."^ •2¿ -2á • ^ fu -2¿ • 2¿ • 2¿ j«; ^ilj ,J^ ^lij ^ilj _ fu ^lij ^ilj _ fu ."iJ _1j .fu ."iJ _1j .fu ."iJ _1j .^ í^ _1J .^ ."iJ ^IJ S e S s s S S s S 's g 's 's 's 's 's 's 's 's 's 's 's 's 's 's 's §j 's 's 's 's -^ ^ ^ Ä ^ ^ -^ ^ ^ QSQQQQQQQQQQQQQQQWQQQQ

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Daniel (1995a); both have a chromosome number of n = 14. The count of M = 14 for Aphelandra tonduzii (Fig. 1) is somewhat surprising and perhaps revealing. While M = 14 is widespread in Aphelandra (in fact, OO if) u-1 t^ 'çjH r-^ 14 is the only haploid number known among the OO '^ '"^ '"^ ^O ^ ^ ^ . CO OO 19 species of the genus that have been both studied Ä0 ,- e oo oo E9 cytologically and vouchered; see McDade 1984; e ^ Í-H rn >I -_ es ^ _; ^ Daniel et al. 1990; Daniel and Chuang 1993), A. ton- oj (sj oj duzii shows many morphological similarities to .Fc^ 5es ~s -s Stenandrium (x = 13). Based on its herbaceous habit (vs. shrubby in most Aphelandra), relatively short and subactinomorphic corollas (vs. longer and strongly zygomorphic in most Aphelandra), stamens that are inserted in the distal 2/3 of the corolla tube and included within it (vs. inserted in the proximal 1/3 of the corolla tube and conspicuously exserted from it in most Aphelandra), 1 have often considered transferring this species, and several morphologi- cally similar ones (e.g., A. siebertii Leonard), to Sten- (13 (13 -^ 03 nî andrium. In fact, Wasshausen (1996) recently trans- (S (B bo ^ O ferred a similar species in this complex, A. amoldii O ° ^ P '^ Mildbr, to Stenandrium. I had assumed that obtain- o o ci O o y y y y ing a chromosome number of 13 (or a multiple of ^ >< X 3 s X X X w w W fd o W w w 13) in one or more of these Central American spe- s 2 2 g U 2 2 s u cies would confirm their affiliation with the latter genus. Our counts from several cells of A. tonduzii are clearly n = 14. Now one must accept either that < this species (and possibly those morphologically H similar to it) truly belongs in Aphelandra, that the diversity of chromosome numbers found in Sten- andrium includes at least one number that is not in a euploid series based on 13, or that Aphelandra and Stenandrium cannot be distinguished on the basis of chromosome numbers. Indeed, distinctions be- tween these genera have never been adequately promulgated. Further morphological studies and additional chromosome counts of species in both genera are desirable. Poikilacanthus comprises fewer than 15 species of perennial herbs and that occur in Mexico, Q Q Central America, and South America (Daniel 1991). This count of M = 14 (Fig. 1) for P. macranthus is the Ü -Ís 4S3 H^ first chromosome number reported for the genus. The species has a widespread distribution, extend- ing from southern Mexico to Panama; some of its 1:5 t? -^ fi = S I morphological variation was discussed by Daniel s ^ -3 c (1991). Lindau (1895) included Poikilacanthus in sub- ^ s a s s •r es -y s s 3 s S S J >§ s^ »- o family Acanthoideae, tribe Isoglosseae, subtribe i II « « •« S I S Porphyrocominae. The genus was distinguished " I i from others in the family primarily on the basis of • S -S ^ •« •« ;S -s •§ 'l S I its pollen with four to eight pores and faceted exine. Raj (1961) noted that this type of pollen is not en- 20 SYSTEMATIC BOTANY [Volume 25

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6 7 8 9 10 1112 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 Haploid Chromosome Number (n )

FIG. 2. Frequency histogram showing the distribution of haploid chromosome numbers reported for species of Justicia. See text for additional information. countered elsewhere in the family. Bremekamp Jxtlania, Jacobinia, Justicia, Rhyticalymma, Rostellularia, (1965) incorporated Lindau's Isoglosseae into the and Siphonoglossa in Federov (1969), Kaur (1969), Justicieae but noted that the taxonomic position of Morton (1978), Ornduff (1967, 1968), Moore (1973, Poikilacanthus in that tribe was unclear. Based on 1974, 1977), Goldblatt (1981, 1984, 1985, 1988), macromorphological and palynological evidence, Goldblatt and Johnson (1990,1991, 1994,1996), and Daniel (1998) concluded that the genus could be Daniel and Chuang (1998). All of these genera were readily accommodated in the Justiciinae. Such a re- treated as synonyms of Justicia by Graham (1988). lationship was subsequently confirmed by data To the extent possible, nomenclatural and taxonom- from chloroplast DNA sequences (McDade and ic synonyms for species treated in these genera Moody 1999). A chromosome number of M = 14 is were resolved based on Graham (1988), Ensermu the most commonly reported number in the related Kelbessa (1990), Daniel (1995b), and other sources. genus Justicia of that subtribe as well (see below). In some cases, nomenclatural combinations in Jus- Chromosome Numbers in Justicia. Justicia is the ticia have not been made for species whose chro- largest genus in the family with between 400 and mosome number was reported in one or more of 600 species worldwide. My count of n = 24 for Jus- these genera. Because non-approximate chromo- ticia galapagana (Fig. 1) is the first report of this some numbers are known for 93 species of Justicia number in the genus. Daniel et al. (1984,1990) not- and 53 of these were included by Graham (1988) in ed that a wide range of chromosome numbers has an infrageneric classification of the genus, some been reported for species of Justicia, with n = 14 preliminary comments on patterns of chromosome being the most common. Figure 2 shows the diver- numbers within the genus are warranted. Graham sity and frequency of numbers reported for the ge- (1988) did not discuss chromosome numbers, but nus. This summary is based on all non-approxi- counts have been reported for species representing mate counts reported for species of Adhatoda, Belo- 13 of the 16 sections she recognized (species treated perone, Chaetothylax, Dianthera, Drejerella, Gendarussa, by Graham as "peripheral" to her sections are not 2000] DANIEL: CHROMOSOMES OF ACANTHACEAE 21 included). Chromosome numbers have been re- Hilsenbeck (1990) used chromosome numbers, in ported for only a single species in several sections conjunction with morphological and phytochemical (e.g., Vasica, Cyrtanthera, Harnieria, and Tyloglossa); data, to recircumscribe the American species of Si- thus patterns are not discernible within these taxa. phonoglossa. He found that four species treated in A diversity of numbers is known for sections Be- Siphonoglossa with equally five-parted calyces, quer- tónica (three species: 13, 14, 17), Chaetothylax (four cetin-based 0-glycosylated flavonols, and chromo- species: 11, 14, 22, 23), Drejerella (three species: 14, some numbers oí n = lA (or multiples of 14) were 15, 31), Rhaphidospora (four species: 13-16, 27, 34), more closely allied to species of Justicia than to oth- and Sarotheca (five species: 11, 12, 14, 22, 24, 28). er species of Siphonoglossa. Species of Siphonoglossa Section Dianthem comprises two subsections; counts sensu stiicto were noted to have four-parted caly- of two species in subsection Strobiloglossa and two ces, apigenin-based C-glycosylflavones, and chro- species in subsection Dianthera are all n = 14. A mosome numbers of n = 11 (or euploid and pre- third count in subsection Dianthera is n = 13. The sumed dysploid derivatives of 11). Although chem- three species counted in subsection Dianthera are all ical constituents of only a few species of Justicia morphologically similar taxa occurring in temper- have been identified, four-parted calyces and chro- ate North America. The count of n = 13 (]. americana mosome numbers of n = 11 are both known in di- (L.) Vahl) likely represents a dysploid derivative of verse species of Justicia. A four-parted calyx is an ancestor with n = 14, which number would ap- found in at least six sections of the genus (Graham pear to be widespread in the section. A meiotic 1988) and n = 11 occurs in at least three sections number of 14 is the only number known in both (see above). As a result, both Graham (1988) and sections Plagiacanthus (four species) and Simonisia Daniel (1995b) have treated Siphonoglossa s.s. within (five species). According to Graham (1988) section Justicia. However, the correlated traits noted by Hil- Rostellaria comprises two subsections. In subsection senbeck (1990) in this assemblage likely delimit a Rostellaria a meiotic number of nine has been re- clade within the genus. ported in all nine species studied. Although n = li The diversity of chromosome numbers so far re- and 18 have also been reported for one species (/. ported for Justicia contrasts with the relative con- simplex D. Don) in this subsection and n = 14, 18, stancy of chromosome numbers reported for some and 28 have also been reported for another {]. pro- other large genera (e.g., Ruellia; see Daniel et al. cumbens L.), the common occurrence of a relatively 1984). A basic number of x = 7 would appear to be low number (i.e., nine) in all the species would ap- highly probable for Justicia, as suggested by Piova- pear to be significant. Among the seven species no and Bernardello (1991), for several reasons: it is studied in subsection Ansellia, n = 9 has been re- the lowest known number in the genus; multiples ported in two. Meiotic numbers among the other of seven are frequent and are known in 11 of the five species in this subsection comprise seven (two 13 sections for which at least one chromosome species) and eleven (three species). number has been reported; and x = 7 is the pre- Subsequent to Graham's (1988) studies, Ensermu sumed basic number of the family (Grant 1955; Ra- Kelbessa (1990) provided evidence to support the ven 1975; Piovano and Bernardello 1991; Daniel and recognition of Ansellia at the sectional rank. He not- Chuang 1993). Other possible basic numbers of Jus- ed that in one species (Justicia anagalloides (Nees) T. ticia include six (although not known in the genus Anderson), in which both n = 9 and n = 18 are or family), nine, and eleven. Multiples of each of known, the diploid number was found in small- these relatively low numbers are also known in the flowered populations whereas a large-flowered genus. Whatever the basic number of Justicia, given population was found to be tetraploid. He also con- the diversity of numbers now known for the genus, cluded that the counts of n = 7 reported for two it appears evident that both dysploidy and euploi- species in this section represent the lowest numbers dy have been important components of evolution reported in the genus; that the occurrence of the within the genus. While Graham's (1988) infrage- unique chromosome number n = 9 in both sections neric classification provides a good beginning for Rostellaria and Ansellia supports their relationship resolving the taxonomy of Justicia, and some pre- as sister taxa; and that the variation in chromosome liminary patterns involving chromosome numbers numbers of section Ansellia contiasts with the rel- are evident in several of her supraspecific taxa, this ative constancy of numbers in some other sections large genus requires considerably more study. (in which evolution appears to have taken place at Patterns of Chromosome Numbers and Suprage- the same ploidal level). neric Relationships. Many of the same chromo- 22 SYSTEMATIC BOTANY [Volume 25 somal patterns that were summarized by Daniel 1984,1990). Morphological boundaries among these and Chuang (1993, 1998) and Daniel et al. (1984, genera have yet to be adequately delimited and the 1990) for Acanthaceae continue to be confirmed by chromosome number determined for A. tonduzii additional studies in the family. For example, wide- raises doubts about some of the correlations be- ly divergent chromosome numbers are sometimes tween taxonomy/morphology and cytology that found within genera, euploidy and/or dysploidy have been promulgated previously (Daniel et al. are encountered at both the specific and generic lev- 1984). els, and haploid numbers for most taxa are rela- The remaining genera studied here, Blechum, Dys- tively high (i.e., M = 14 or more). The diversity of choriste, and Ruellia, belong to the tribe Ruellieae. A basic numbers previously postulated for genera in basic number of x = 17 appears to be shared by the family (Piovano and Bemardello 1991; Daniel both Blechum and Ruellia (Daniel et al. 1984; Daniel and Chuang 1998) is also reaffirmed. Given a prob- and Chuang 1998). Macromorphological similari- able basic number of x = 7 for the family, most of ties between these genera are well-known (Daniel the counts reported here are relatively high. The et al. 1984; Daniel 1998) and trnL-trnF chloroplast high basic numbers suggested for most genera un- DNA sequences (McDade and Moody 1999) strong- doubtedly result from ancient polyploidizations. ly support a close phylogenetic relationship be- Species with the highest known chromosome num- tween them. Blechum and Ruellia undoubtedly bers in the family, n = 56 in spinosus L. shared a common ancestor with x = 17. They are (Sugiura 1939; Daniel and Chuang 1998) and n = readily distinguishable from one another on the ba- 68 in nobilis Hook. f. (Singh 1951; Kaur sis of palynological and carpological characters 1970), would appear to represent evolution to the (Daniel 1995c). Chromosome numbers have been octoploid and decaploid levels respectively. Given reported for 11 species of Dyschoriste. Both n = 15 the variation in chromosome numbers reported and n = 30 are common to species from the Old within numerous species and genera, it is likely that World and the New World with the former number chromosomal alterations have been responsible for reported for eight species. A basic number of x = some of the proliferation in numbers of taxa in this 15 appears likely for Dyschoriste. Thus, chromosome large family. Thus, differences in chromosome number differences support molecular data (Mc- numbers should prove useful in reconstructing Dade and Moody 1999) in suggesting that Dyschor- probable phylogenies of Acanthaceae. iste is less closely related to either Ruellia or Blechum Bremekamp (1965) recognized 12 tribes within than these latter genera are to one another his narrow concept of Acanthaceae (i.e., the Acan- Suprageneric classification of Acanthaceae is cur- thoideae of Lindau 1895). Chromosome numbers rently undergoing modification based largely on reported here represent only three of Bremakamp's phylogenetic relationships as revealed by DNA se- tribes: Aphelandreae, Justicieae, and Ruellieae. quence data (Hedrén et al. 1995; Scotland et al. Nine of the genera studied here belong to the 1995; McDade and Moody 1999). These studies Justicieae: Anisacanthus, Asystasia, Carlowrightia, Di- (and others in preparation) reveal that several of the diptera, Justicia, Odontonema, Poikilacanthus, Pseuder- major taxonomic groupings recognized by Breme- anthemum, and Tetratmrium. It has been indicated kamp (1965) based on morphology form monophy- previously (Daniel et al. 1990; Daniel and Chuang letic clades whereas others need to be reassessed. 1993, 1998) that diversity of chromosome numbers Correlations between chromosome numbers and among several of these (and other) genera, com- some suprageneric groupings suggest that an ex- bined with morphological data, suggest potential panded knowledge of chromosome numbers will infratribal relationships with at least three supra- be helpful in clarifying infrafamilial relationships generic groups discernable among Neotropical in the Acanthaceae. taxa: , Odontonema, and their rela- Chromosome numbers recently obtained in two tives with n = 21; Anisacanthus, Carlowrightia, Tetra- genera of Acanthaceae for which chromosome merium, and their relatives with n = 18; and New numbers were previously unknown, Poikilacanthus World Dicliptera with n = 40. (see above) and (Daniel 1999), have Three genera in which chromosome numbers helped to confirm their suspected systematic affin- were determined here, Aphdandra, Holographis, and ities. In order to be of greatest value for under- Stenandrium, represent Bremekamp's Aphelandreae. standing relationships among Acanthaceae, efforts Aphdandra appears to have x = 14 whereas Holo- to obtain chromosome numbers in tribes and gen- graphis and Stenandrium have x = 13 (Daniel et al. era for which there are no counts should continue. 2000] DANIEL: CHROMOSOMES OF ACANTHACEAE 23

For example, chromosome numbers remain unde- BRUMMITT, R. K. 1992. families and genera. termined in Bremekamp's tribes Haselhoffieae, Royal Botanic Gardens, Kew. Louteridieae, Rhombochlamydeae, and Whitfiel- DANIEL, T. F. 1983. Carlomrightia (Acanthaceae). Flora Neo- tropica. 34: 1-116. dieae. In addition, chromosome numbers have yet . 1991. A synopsis of Poikilacanthis (Acanthaceae) in to be determined for 161 of the 228 genera of Acan- Mexico. Bulletin of the Torrey Botanical Club 118: thaceae recognized in Brummitt (1992). Chromo- 451-158. some number variation both within genera and . 1995a. justicia masiaca (Acanthaceae), a new species species also needs further investigation and docu- from northwestern Mexico. Brittonia 47: 408^13. mentation. Some of the pitfalls of relying on single . 1995b. Acanthaceae. In Flora of Chiapas, ed. D E. counts were noted by Darlington (1956; e.g., pres- Breedlove, 4: 1-158. California Academy of Sciences, ence of unidentified B chromosomes) and increased San Francisco. sample size should be a priority in taxa where only . 1995c. New and reconsidered Mexican Acantha- one or a few counts have been made. Finally, sam- ceae. VI. Chiapas. Proceedings of the California Acad- ple sizes should be increased by analyzing taxa emy of Sciences 48: 253-284. . 1998. Pollen morphology of Mexican Acanthaceae: from geographic regions rich in Acanthaceae but diversity and systematic significance. Proceedings of underrepresented by studies of chromosome cytol- the California Academy of Sciences 50: 217-256. ogy involving them (e.g., southeastern Asian main- . 1999. Revision of Stenostephanus (Acanthaceae) in land, Malesia, southern Africa, Madagascar, Brazil, Mexico. Contributions from the University of Michi- and Andean South America). gan Herbarium 22: 47-93. . In press. Chromosome numbers of some Papua- ACKNOWLEDGEMENTS. I am grateful to the following sian Acanthaceae. Austrobaileya. individuals who facilitated or assisted with the field stud- and T. I. CHUANG. 1993. Chromosome numbers of ies: S. Acosta C, F. Almeda, B. Bartholomew, D. Breedlove, New World Acanthaceae. Systematic Botany 18: 283- M. Correya, A. Gavazzi, M. González, V. Lee, J.-L. León de 289. la Luz, J. Luteyn, L. McDade, G. Olalde, W. Trauba, I. Val- and . 1998. Chromosome numbers of culti- despino, T. and A.-L. Van Devender, A. Ton, and B. Win- vated Acanthaceae and systematic implications. Pp. ning. Frank Almeda and Mariette Manktelow kindly col- 309-330 in P Mathew and M. Sivadasan (eds.). Di- lected buds of several species for me. George Marcopulos, versity and Taxonomy of Tropical Flowering Plants. director of the San Francisco Conservatory of Flowers, Mentor Books, Calicut. generously provided greenhouse space in which to grow , , and M. A. BAKER. 1990. Chromosome several of the species. Funding for field studies was pro- numbers of American Acanthaceae. Systematic Bota- vided by the American Philosophical Society, the In-House ny 15: 13-25. Research Fund of the California Academy of Sciences, , B. PARFITT, and M. A. BAKER. 1984. Chromosome Oceanic Society Expeditions, and the National Science numbers and their systematic implications in some Foundation (BSR-8609852). Logistical support in the field North American Acanthaceae. Systematic Botany 9: was enhanced by the Smithsonian Tropical Research In- 346-355. stitute (Panama), Lamanai Outpost Lodge (Belize), El Col- DARLINGTON, C. D 1956. Chromosome botany. George Al- egio de la Frontera Sur (Mexico), the Fransican Mission at len & Unwin Ltd., London. the Iglesia de Nuestra Señora de Guadalupe in Yecora DE, A. 1966. Cytological, anatomical and palynological (Mexico), and the Museo Nacional de Costa Rica (Costa studies as an aid in tracing affinity and phylogeny in Rica). the family Acanthaceae. I. Cytological Studies. Trans- This contribution is dedicated to the memory of my actions of the Bose Research Institute, Calcutta 29: friend and colleague, T.I. Chuang (1933-1994), who en- 139-175. couraged my interest in chromosomal cytology, made DYER, A. F, K. JONG, and J. A. RATTER. 1970. Aneuploidy: many counts of Acanthaceae, and co-authored four papers a redefinition. Notes from the Royal Botanic Garden, on chromosome numbers of Acanthaceae with me. His Edinburgh 30: 177-182. friendship, enthusiasm for botany, and research produc- ELLIS, J. L. 1962. Chromosome numbers in some members tivity continue to inspire me. His wife, Fei-Mei Chuang of Acanthaceae. Science and Culture 28: 191-192. continues to provide expert technical assistance to me and ENSERMU KELBESSA. 1990. Justicia sect. Ansellia (Acantha- others in our efforts to count chromosomes. ceae). Acta Universitatis Upsaliensis Symbolae Botan- icae Upsalienses 29(2): 1-96. LITERATURE CITED FEDEROV, A. A. (ed.). 1969. 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