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4-1997 Revision of the cerrado hemicryptophytic of Boissier's "Pleiadeniae" () Mark P. Simmons

W. John Hayden University of Richmond, [email protected]

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Recommended Citation Simmons, Mark P., and W. John Hayden. "Revision of the Cerrado Hemicryptophytic Chamaesyce of Boissier's 'Pleiadeniae' (Euphorbiaceae)." Brittonia 49, no. 2 (April 1997): 155-80. doi: 10.2307/2807678.

This Article is brought to you for free and open access by the Biology at UR Scholarship Repository. It has been accepted for inclusion in Biology Faculty Publications by an authorized administrator of UR Scholarship Repository. For more information, please contact [email protected]. Revision of the cerrado hemicryptophytic Chamaesyce of Boissier's "Pleiadeniae" (Euphorbiaceae)

MARK P. SIMMONS 1 AND W. JOHN HAYDEN

Simmons, M. P. (Department of Biology, University of Richmond, Richmond, VA 23173, U.S.A.) and W. J. Hayden (Department of Biology, University of Richmond, Richmond, VA 23173, U.S.A.). Revision of the cerrado hemicrypto- phytic Chamaesyce of Boissier's "Pleiadeniae" (Euphorbiaceae). Brittonia 49: 155-180. 1997.---The of Chamaesyce classified by Boissier as the "Pleia- deniae'" are revised in light of presently available collections. Six species are accepted and new combinations are proposed for C. nana, C. setosa, C. taman- duana, and C. viscoides. Although these herbaceous perennials of cerrado veg- etation of Brazil, northern Argentina, and adjacent countries are distinctive eco- logically and geographically, cladistic analysis does not support their recognition as a monophyletic group. Key words: Chamaesyce, , Euphorbiaceae, cerrado.

This systematic revision focuses on sev- dition for Chamaesyce (Webster, 1967). Po- eral Chamaesyce with hemicryptophyte tentially, then, the species of Boissier's growth habits that are endemic to the cer- "Pleiadeniae" may prove pivotal in under- rado vegetation of southeastern Brazil and standing the evolution of Chamaesyce with- adjacent countries. These distinctive species in tribe Euphorbiae. This taxonomic revi- of Chamaesyce are perennial that sion presents a beginning step in exploring produce seasonal aerial stems from thick- the phylogenetic position of these cerrado ened rootstocks that extend deeply into the hemicryptophytes in the genus Chamaesy- soil. Although uncommon in Chamaesyce, ce. the hemicryptophyte habit is significant in several respects. Ecologically, it is clear A Note on Subgeneric Taxa in that this habit is effective for survival of the Chamaesyce seasonal droughts and periodic fires that characterize cerrado. Taxonomically, the Among the plants presently known to co-occurrence of several hemicryptophyte constitute the genus Chamaesyce, Boissier species of Chamaesyce in a well-defined defined eight taxa which he recognized as geographic and ecological setting led to subsections of Euphorbia sect. Anisophyl- their classification together in a group that lure. Five of Boissier's subsections have Boissier (1862) termed the "Pleiadeniae." been treated formally as subgeneric taxa of Phylogenetically, the hemicryptophyte Chamaesyce (Hurusawa, 1954; Koutnik, growth habit is shared with certain Euphor- 1987; Webster, 1967; Webster et al., 1982). bia species of subgen. Agaloma (Raf.) As discussed below, there is doubt that the House and subgen. Esula Pers. and thus has remaining groups, including "Pleiaden- been hypothesized to be the primitive con- iae," constitute definable monophyletic groups. When referring to these dubious taxa, we therefore will employ the strictly 1Current address: L. H. Bailey Hortorium, 462 Mann Library, Cornell University, Ithaca, NY 14853- informal device of placing the Boissierian 4301, U.S.A. names in quotation marks.

Brittonia, 49(2), 1997, pp. 155-180. ISSUED: 30 June 1997 1997, by The New York Botanical Garden, Bronx, NY 10458-5126 156 BRITTONIA [VOL. 49

Taxonomic History study, the publications of Boissier (1862) and Mueller Argoviensis (1874) were the The species that constitute Boissier's most recent inclusive taxonomic syntheses "Pleiadeniae" are based on early-19th-cen- of the group. tury collections of Blanchet, d'Orbigny, A number of piecemeal taxonomic ad- Lund, Pohl, Regnell, Riedel, Sellow, and justments pertinent to "Pleiadeniae" oc- Widgren. Prior to being grouped together in curred sporadically in this century. Two a formally defined taxon, the species treated new species were proposed, one by Chodat herein were first named by Klotzsch and (1901) and the other by Pax and Hoffmann Garcke (in Klotzsch, 1859) as species of (in Emrich, 1937). Two new varieties were Anisophyllum Haw. or by Boissier (1860) proposed, one each by Chodat and Hassler as species of Euphorbia L. Subsequently, (1905) and Croizat (1943). We recognize Boissier (1862) defined Pleiadeniae as a none of these taxa. Croizat (1943) trans- subsection of Euphorbia sect. Anisophyllum ferred four of the seven Brazilian taxa from Roep. to include these hemicryptophyte Euphorbia to Chamaesyce, without com- species from Brazil, plus one other from ment about the other three. In terms of ge- Mexico. The Mexican species, Euphorbia netic placement, we follow Croizat's (1943) macropus (Klotzsch & Garcke) Boiss., has lead and recognize all the cerrado hemi- since been recognized as extraneous and cryptophytes of "Pleiadeniae" as elements has been referred to Euphorbia subgen. of the genus Chamaesyce, an approach fre- Agaloma (Huft, 1979; Webster, 1967). It is quently adopted for these distinctive plants significant to note that E. macropus pos- (see, e.g., Benedf & Orel, 1992; Koutnik, sesses cyathia with five glands: as defined 1987; Lin et al., 1991; Webster, 1967, and described by Boissier, three of the Bra- 1994). zilian taxa also possess, at least sometimes, Several members of Boissier's "Pleia- more than the usual four glands per cy- deniae" have been treated in regional floras athium found in other Chamaesyce--hence (Allem, 1977; Allem & Irgang, 1975; Ram- the name "Pleiadeniae" for the subsection bo, 1960; Subils, 1977), always as species (from the Greek pleion more, aden gland). of Euphorbia and often with circumscrip- Other characters used in Boissier's loose tions somewhat at variance with earlier lit- definition of "Pleiadeniae" include the erature and/or our concepts. For example, erect, often strigose stems, relatively large Rambo (1960) and Allem and Irgang cyathia, and two leaf features unusual for (1975) synonymized E. chamaerrhodos and Chamaesyce. Compared to other Chamae- E. setosa with E. selloi; however, Allem syce, leaf bases in "Pleiadeniae" tend to be (1977) later recognized E. chamaerrhodos only weakly oblique. Further, instead of the as distinct. It is noteworthy that, within the usual strictly opposite condition, two of the limits of their floristic studies, both Allem species recognized by Boissier possess and Irgang (1975) and Subils (1977) re- some leaves in verticils; we treat these two ferred E. selloi to subsect. Hypericifoliae as a single species. In all, Boissier included and retained only E. caecorum within seven Brazilian taxa in "Pleiadeniae" " Pleiadeniae." without further comment about their rela- tionships inter alia: E. caecorum Mart. ex Taxonomic Characters Boiss., E. chamaerrhodos Boiss., E. poten- tilloides Boiss., E. selloi Boiss., E. selloi The cerrado hemicryptophytes described var. setosa Boiss., E. tamanduana Boiss., herein possess irregularly thickened, some- and E. viscoides Boiss. what twisted, more or less vertical root- Although he did not use the subsectional stocks (Figs. 1A, IF, 4, 5,) from which sea- designation, Mueller Argoviensis (1874) sonal aerial stems diverge apically. Occa- treated the species of "Pleiadeniae" much sionally, bases of aerial stems persist as had Boissier, the only important differ- through the winter/dry season. In most spe- ence being the elevation of E. selloi vat. cies, the annual stems first develop vege- setosa to specific status. Until the present tatively for several nodes before producing 1997] SIMMONS & HAYDEN: EUPHORBIACEAE 157

D ~ A C

iF E

FIG. 1. Morphology of hemicryptophyte Chamaesyce species, from dried pressed material. A. Habit of common form of C. potentilloides (Mimura 131, NY). B. Distal nodes of C. potentilloides late-season form (Dawson 14584, RSA). C. Distal nodes of C. tamanduana (Blancher 3841, G). D, Distal nodes of C. setosa (Schinini 12101, G). E. Distal nodes of C. setosa (Barreto 2600, F). F. Habit of C. nana (Hassler 8498, NY). (Scale bars: A, E 2 cm bar; B-E, 1 cm bar.) cyathia; however, this sequence is reversed phylls. As is typical of Chamaesyce, leaves in C. nana (Fig. 1F), in which vegetative are strictly opposite and distichous, except shoots arise by apical proliferation of short, for the characteristic production of at least early-season-flowering stems. Unfortunate- a few verticils associated with early-season ly, seedling stages of cerrado hemicrypto- pleiochasial branching in C. potentilloides phyte species of Chamaesyce remain un- (Fig. 1A). A single anomalous ternate node described, so it is unknown whether epi- was also observed in one specimen of C. cotyls persist or exhibit the abbreviated (so- viscoides. Foliage leaves and cyathophylls called abortive) ontogeny typical of of all the species possess chlorenchymatous Chamaesyce (Hayden, 1988; Koutnik, bundle sheaths characteristic of the C4 pho- 1984, 1987; Lin et al., 1991). tosynthetic pathway (Figs. 2, 3; see also Leaves grade continuously from basal Webster et al., 1975). Leaf bases are dis- cataphylls to foliage leaves and cyatho- tinctly oblique except in Chamaesyce po- 158 BRIq"FONIA [VOL. 49

FIGS. 2-5. Leaf and rootstock anatomy of hemicryptophyte Chamaesyce. 2. C. potentilloides, cross section of leaf (Ezechias 14134, US). 3. C. potentilloides, paradermal section of leaf (Irwin 18684). 4. C. potentilloides, cross section of root (Eiten & Eiten 8653, NY). 5. C. nana, cross section of root (Pedersen 6548, NY). (Scale bars: 2, 3 = 100 ~Lm; 4, 5 = 1 mm.)

tentilloides. Leaf margins are somewhat ly in the flowering stage, but eventually this thickened, and apices are acute. Petiole bas- pleiochasial pattern becomes strictly dicha- es are connected by persistent connate stip- sial, i.e., cyathia are subtended by paired ules that are generally triangular and acute cyathophylls and their axillary branches. A but range from entire to deeply cleft. further simplification of this system occurs The architecture of flowering stems of C. in stems of C. potentilloides that continue potentilloides (Fig. 1A) appears directly to grow and flower for an extended period comparable to that of Euphorbia subgen. of time (Fig. 1B); these late-season stems Esula and subgen. Agaloma, and is thus become pseudomonopodial by suppression unique within Chamaesyce. In C. potentil- of one branch at each node of the potential loides, as in Euphorbia subgenera Esula dichasium. The pleiochasial architecture of and Agaloma, the transition from vegetative C. potentilloides differs from that of Eu- growth to flowering is marked by produc- phorbia subgen. Esula and subgen. Agalo- tion of a terminal cyathium subtended by a ma in that the first cyathium-bearing verticil whorl of leaves (cyathophylls); branches arises above cataphylls without intervening arise in the axils of each whorled leaf; these foliage leaves (Fig. 1A). Pleiochasial archi- branches are leafless proximally, but ter- tecture would seem reasonably hypothe- minate in another cyathium which is, in sized as plesiomorphic for Chamaesyce; re- turn, subtended by either another whorl or suits of the phylogenetic analysis, however, pair of leaves; this pattern reiterates through suggest that this growth in habit in C. po- several nodes. Verticils may occur for as tentilloides may be an evolutionary reversal many as three successive nodes formed ear- (see below). It is, perhaps, significant to 1997] SIMMONS & HAYDEN: EUPHORBIACEAE 159

note that much of the range of phyllotaxy Schoute, 1937; Weberling, 1989). Five and branch architecture variation known in lobes end freely in acute apices and are re- Chamaesyce can be found within C. poten- ferred to herein as primary lobes. Alternate tilloides. with the primary lobes are five potentially Cyathium production in other Chamae- glandular secondary lobes. In many species syce, including the other hemicryptophyte of Euphorbia subgen. Esula and subgen. species included in this study, does not rou- Agaloma, each of the secondary lobes bears tinely involve verticillate nodes or plei- a terminal gland which in subgen. Agaloma ochasial branching systems. In fact, aside also bears an appendage comparable to from C. potentilloides, we have seen only those found in Chamaesyce. In some spe- one example of pleiochasial architecture in cies of subgenera Esula and Agaloma and Boissier's "Pleiadeniae," a single stem of in virtually all Chamaesyce, only four of C. viscoides. Cyathium production is dicha- the five secondary lobes are glandular. sial and/or pseudomonopodial in three of Thus, in Chamaesyce there is always one the hemicryptophyte species revised here, segment of the rim of the involucre that C. nana (Fig. 1F), C. tamanduana (Fig. bears three adjacent acute lobes, the non- 1C), and C. viscoides; their patterns of cy- glandular secondary lobe flanked by two athium production are widespread in Cha- primary lobes. In the case of C. potentil- maesyce. On the other hand, cyathia in C. loides, cyathia that bear more than four selloi (Fig. 1D) and C. setosa (Fig. 1E) are glands do so by the presence of additional solitary on main stems and clustered in pairs of primary and secondary lobes, but groups of 2-12 in apparently lateral glom- the number of glands is still, at most, one erules. Within these glomerules, peduncles less than the number of secondary lobes. In are short and subtending cyathophylls are other words, the overall meristic organiza- highly reduced to essentially obsolete; tion of the cyathium is greater than usual, sometimes several cyathia may appear to with retention of at least one non-glandular arise from the same node or share a com- secondary lobe. mon short stipe. Glomerulate architecture The propensity for greater than 5-merous of C. selloi and C. setosa appears directly cyathia in C. potentilloides suggests the comparable to that found in sect. Hyperi- need for careful consideration of the appar- cifoliae and we agree with Lin et al. (1991) ently simple character of gland number. It in hypothesizing that such glomerules are appears that two factors may affect total probably derived from equal dichasia by a gland number for any given cyathium: its process of overtopping. overall meristic organization and the pro- As mentioned above, cyathia in Chamae- portion of glandular secondary lobes, i.e., syce usually bear four appendaged glands, whether there are any non-glandular sec- but additional glands and appendages occur ondary lobes. Distinguishing these two fac- in some "Pleiadeniae" (Fig. 6C). Accord- tors may have phylogenetic implications. ing to the adopted herein, cyathia For example, it has been hypothesized that with more than four appendaged glands are evolution from Euphorbia to Chamaesyce routinely encountered only in C. potentil- involved a decrease from five glands to four loides, for which glands may number up to (e.g., Webster, 1967), but 4-glanded 5-mer- seven. The "extra" glands are not merely ous cyathia are known in a significant frac- unusual outgrowths at the rim of the invo- tion of the species of subgen. Agaloma lucre; they are an expression of the funda- (Hurt, 1979); they may also be found in sub- mental meristic organization of the cy- gen. Esula, for example, in E. lathyrus athium itself. (Hayden, unpubl, obs.). Consequently, it The rim of the cyathial involucre in most appears that one often-cited distinguishing Chamaesyce and, for that matter, a great feature of Chamaesyce, gland absence or many Euphorbia as well, reveals 10 more suppression on one secondary lobe, either or less evenly spaced lobes that are inter- pre-dates the origin of Chamaesyce or preted to represent the tips of fused phyl- evolved more than once. lomes and their stipules (Haber, 1925; Variation in the meristic organization of 160 BRITTONIA [VOL. 49

FIG. 6. Cyathia of hemicryptophyte Chamaesyce species, from dried pressed material. A. C. viscoides (Fon- sOca & Onishi 1042, LIB). B. C. selloi (Cristobal et al. 2069, CTES). C. C. potentilloides, robust form (Irwin et al. 9924, UB). I). C. potentilloides, linear leaf form (Dus~n 16450, NY). E. C. setosa (Irwin et al. 27209, NY). F. C. nana (Sellow 3131, MO). G. C. tamanduana (Blancher 3841, G). cyathia has not been well documented and cies. As far as is known, 5-merous cyathia is clearly in need of study across a wide seem fixed in all other species of Chamae- range of species in tribe Euphorbieae. Huft syce. (1979) noted that the first cyathium on Glands of the six species treated herein are flowering stems of E. pubentissima Michx. routinely very short stalked, concave above, (sometimes included within E. corollata minutely pitted, and appendaged. Cyathial L.)--i.e., the cyathium subtended by the appendages are more or less parallel veined first order of pleiochasial branching--is of- and, in C. nana, C. potentilloides, and C. se- ten more than 5-merous and the same can tosa, of equal size and shape. Cyathia of C. be seen in E. marginata Pursh and E. lath- seUoi rarely have two appendages slightly yrus L. (Hayden, unpubl, obs.); the phe- larger than the other two. Chamaesyce ta- nomenon of pleiomerous early cyathia thus manduana has two wide and two narrow ap- occurs in both subgenera Agaloma and Esu- pendages of nearly equal length (Fig. 6G). In la. It would seem reasonable to propose that C. viscoides, however, two appendages are such pleiomery is plesiomorphic for Cha- distinctly smaller than the others (Fig. 6A). maesyce potentilloides; our phylogenetic The appendages of C. tamanduana are dis- analysis, however, suggests pleiomerous tinctly papillate, whereas those of the other early cyathia may be a reversal for this spe- species are always smooth. 1997] SIMMONS & HAYDEN: EUPHORBIACEAE 161

Another aspect of the meristic organiza- relationship of "Pleiadeniae'" to other sub- tion of cyathia involves the pattern of sta- sections in Chamaesyce. minate flower production. Generally, sta- minate flowers of Euphorbia and Chamae- TAXA INCLUDED IN THE ANALYSIS syce occur in five linear, radial, cincinnoid The taxa selected for inclusion in the groups that are located opposite the primary analysis were a single outgroup, Euphorbia lobes; the monandrous staminate flowers corollata L. from Euphorbia subgen. Aga- mature centrifugally. In C. potentilloides, loma, four species in "Pleiadeniae," and the number of staminate cincinni corre- representative species from the following sponds to the number of primary lobes, i.e., subgeneric groups of Chamaesyce: Acutae up to eight. As is typical of most Chamae- (Boiss.) Webster, Sclerophyllae (Boiss.) syce, glands are four and staminate cincinni Hurus., Chamaesyce, Hypericifoliae are five in the other hemicryptophyte spe- (Boiss.) Hurus., and Gymnadeniae (Boiss.) cies that constitute this revision. Koutnik. Subsections "Cheloneae" and Pollen grains of C. nana, C. potentillo- "Elegantes" of Boissier (1862) were not ides, C. selloi, and C. setosa were studied included in this analysis due to lack of in- by SEM (Figs. 7-11). The grains of these formation and because they do not appear species are similar to each other and consist distinct from sect. Hypericifoliae, which of isopolar monads with elongate colpi. was included in the analysis. Of the species Shape is ellipticM in equatorial view and revised here, C. selloi was not included in deeply three-lobed in polar view. Polar di- the analysis because it was coded identical- mensions range from 23 to 30 Ixm. The sur- ly to C. setosa. Further, C. tamanduana was face is minutely pitted. Similar grains are not included because it would have coded found throughout tribe Euphorbieae (Punt, identically to C. viscoides except that ex- 1962; Lopez & Diez, 1985). istence of seed mucilage in C. tamanduana As is routine in cyathia of Chamaesyce is unknown. When C. tamanduana was in- and Euphorbia, pistillate flowers are cen- cluded in the analysis, C. tamanduana tral, solitary, and exserted with age by formed a polytomy at the same node as C. means of an accrescent and reflexed gyno- viscoides. phore. The 3-carpellate bears a lobed hypogynous disk and three basally connate CHARACTERS INCLUDED IN THE ANALYSIS styles. Capsules are broadly ovoid, weakly keeled and ballistically dehiscent. The light Thirteen morphological, developmental, brown to gray, ecarunculate seeds are sub- and anatomical characters were included in ovoid, narrowed apically, truncate and con- the final data matrix (Tables I & II). Addi- cave basally, and more or less tetragonai in tional characters were considered, but prob- cross section; the raphe is somewhat de- lems of doubtful character independence, pressed (Fig. 12). Mature seeds of most ambiguous character state coding, and/or species of Chamaesyce produce mucilagi- the amount of missing data precluded their nous exudations upon exposure to moisture use. The two multistate characters, plant (Jordan & Hayden, 1992); except for C. ta- form and phyllotaxy, were coded as non- additive (unordered) because the relation- manduana, which has not been tested be- ships among the character states are unclear. cause of lack of material, this phenomenon Autapomorphic characters were not includ- has been observed in the hemicryptophytic ed. Seedling ontogeny is unknown for the species of "Pleiadeniae." four species in subsect. "'Pleiadeniae" for which this character was coded as missing Phylogenetic Analysis data.

The purpose of this analysis was to as- ANALYSES PERFORMED certain whether the six species of Chamae- syce subsect. "Pleiadeniae" represent a Hennig86 (Farris, 1988) was used with monophyletic subsection and determine the the ie* option to search for the most par- 162 BRITTONIA [VOL. 49

FIGS. 7--12. Pollen and seed of hemicryptophyte Chamaesyce species. 7. C. potentilloides, pollen, polar view (Richards 6882, NY). 8. C. potentilloides, pollen (Macedo 3729, NY). 9. C. selloi, pollen (Schinini et al. 8313, G). 10. C. setosa, pollen (Irwin 25142, NY). 11. C. nana, pollen (Pedersen 6548, NY). 12. C. potentilloides, seed, ventral surface (Rosengurtt 8898, MFVA). (Scale bars: 7-11 = 10 Ixm; 12 = 500 p.m.) simonious unweighted trees by implicit (Farris, 1988) was used for successive enumeration. Implicit enumeration is cer- weighting. Pee-Wee searches by branch tain to find all of the shortest trees (Farris, swapping for trees with maximum total fit. 1988). Pee-Wee (Goloboff, 1993b) was The fit of each character is based on a con- used for implied weighting with fifty rep- cave function of homoplasy. Characters lications and fifty trees held, and Hennig86 with greater homoplasy are less fit and 1997] SIMMONS & HAYDEN: EUPHORBIACEAE 163

TABLE I TABLE II CHARACTERS AND CHARACTER STATES USED IN THE DATA MATRIX OF CHARACTERS USED IN THE PHYLOGENETIC ANALYSIS PHYLOGENETIC ANALYSIS

0. Plant form: hemicryptophyte (0); therophyte (1); 0 5 10 phanerophyte (2) [nonadditive]. Euphorbia subgen. Agaloma I I I 1. Plant habit: erect (0); procumbent (1). E. corollata 0000000000000 2. Phyllotaxy: spiral (0); decussate (1); distichous (2) [nonadditive]. Chamaesyce sect. Acutae 3. Leaf margin: strictly entire (0); entire to serrulate (1). C. acuta 0010010100100 4. Kranz leaf anatomy: absent (0); present (1). C. angusta 0010010101001 5. Pleiochasium presence: present (0); absent (1). Chamaesyce sect. Chamaesyce 6. Cyathium arrangement: strictly solitary (0); soli- tary to glomerulate (1). C. maculata 1121110101111 7. Cyathium meristic plan: some >5-merous (0); C. serpens 1120110100111 strictly 5-merous (1). Chamaesyce sect. Hypericifoliae 8. Appendange presence: present (0); absent (1). C. hirta 1021111101111 9. Seed surface: smooth (0); rugose (1). 10. Seed mucilage: absent (0); present (1). Chamaesyce ""Pleiadeniae" 11. Mature seed size: reaching 1.5 mm or longer (0); C. nana 002111010110? strictly -<1.1 mm (1). C. potentilloides 002010000010? 12. Seedling ontogeny: continuous (0); aborted axis (1). C. setosa 002111110110? C. viscoides 00201?010110? Chamaesyce sect. Sclerophyllae subsect. Gymnadeniae C. arnottiana treated as less influential in comparing tree 2021111111001 C. atrococca 2010111111001 topologies. When there is conflict between C. celastroides 2020111117101 two characters, the fittest trees have fewer C. multiformis 2020111111001 steps for the character with the higher fit Chamaesyce sect. Sclerophyllae subsect. Sclerophyllae (Goloboff, 1993a). Implied weighting is C. chamissonis 2020111100001 similar to successive weighting (Farris, C. mesemb ryanthifolia 2020110100001 1969) except for this difference: successive weighting does its first analysis using equal character weights, and it weights the char- 1993) was used to visualize character state acters by the rescaled consistency index changes and print cladograms. (consistency index X retention index) on the subsequent analyses, whereas implied RESULTS AND DISCUSSION OF THE ANALYSIS weighting uses a modification of the con- sistency index (Goloboff, 1993a). The de- Hennig86 produced four equally parsi- fault concavity of 3 was used in implied monious unweighted trees with lengths of weighting. Eve (Farris, 1991) was used to 27 steps, consistency index of 0.55, and re- construct Adams consensus trees (Adams, tention index of 0.70. Successive weighting 1972). Unlike a strict consensus tree (Sokal using Hennig86 resulted in the same four & Rohlf, 1981), in which only components equally parsimonious trees with lengths of identical in all trees are resolved (the un- 27 steps when the characters are mapped as ions), in an Adams consensus tree the in- equal weights. Implied weighting using tersections of components between trees are Pee-Wee resulted in ten trees of equal fit. resolved. Adams consensus trees are partic- When the characters are mapped as equal ularly useful in discerning "wildcard" taxa weights, one tree had a length of 27 and (Nixon & Wheeler, 1990) which cause loss nine trees had a length of 28. of resolution in the strict consensus tree. In the unweighted (and successively Bremer (1990) summarizes: "Adams weighted) strict consensus tree (Fig. 13), (1972) consensus trees essentially work by which is also one of the four most parsi- pulling down unstable taxa and components monious trees, Acutae, as previously de- with different positions in the cladograms fined, is paraphyletic and basal (a lineage to the first node summarizing the different that formed early in the evolution of a positions." ClaDOS version 1.4 (Nixon, group) within Chamaesyce. Sclerophyllae is 164 BRITFONIA [VOL. 49

~F~_c~176 acuta 9 ? ACUTAE angusta )

o F rnesembryanthemif~ SCLEROPHYLLAE [--~ F chamiss~ )

] [ L 9_ ~--g--atroc0cca I 2 4 I '---llm[ ~ l GYMNADENIAE ~-I-celastr~ /

" i "PLEIADENIAE" HYPERICIFOLIAE

} CHAMAESYCE serpens

FIG. 13. Cladogram of Chamaesyce. Strict consensus of four most parsimonious unweighted trees; this is also one of the most parsimonious unweighted trees. Character numbers as in Table L Solid box = synapomor- phy; darkly shaded box = parallel change; lightly shaded box = reversal. rendered paraphyletic if Gymnadeniae is In the implied weighted Adams consensus separated from it at the same taxonomic tree, C. potentilloides is placed with C. acuta level. "Pleiadeniae" is a pectinate paraphy- in a trichotomy, basal within Chamaesyce, in letic group with C. potentilloides basal. contrast to the unweighted strict consensus Chamaesyce viscoides (and C. tamandu- tree in which C. potentilloides is the first de- ana) is an ensuing lineage, and C. nana and rived member of a paraphyletic "'Pleiaden- C. setosa (and C. selloi) are derived (a lin- iae." This placement of C. potentiUoides rep- eage that formed later in the evolution of a resents the intersection of its positions in the group) within "Pleiadeniae." Section Hy- 10 implied weighted trees of equal fit. One pericifoliae, represented only by C. hirta, is of the 10 trees has the same topology as the the sister group to sect. Chamaesyce. unweighted (and successively weighted) strict The unweighted strict consensus tree is consensus tree (Fig. 13). In the other nine more resolved than the implied weighted trees, C. potentilloides is represented as the Adams consensus tree; there are four nodes sister group to the rest of Chamaesyce (i.e., in the unweighted strict consensus tree that it is the earliest derived member of Chamae- are collapsed in the implied weighted Ad- syce), which also results in a polyphyletic ams consensus tree (Fig. 14). However, "Pleiadeniae," with C. acuta and C. angusta both the Hypericifoliae/Chamaesyce and derived after C. potentilloides but before the the Sclerophyllae/Gymnadeniae clades are remaining members of "Pleiadeniae." In still resolved in the implied weighted Ad- none of the 10 equally fit implied weighted ams consensus tree. trees is "Pleiadeniae" a monophyletic group. 1997] SIMMONS & HAYDEN: EUPHORBIACEAE 165

--corollata --acuta ACUTAE potentilloides "PLEIADENIAE" --angusta ACUTAE nana / setosa "PLEIADENIAE" --viscoides , hirta HYPERICIFOLIAE

~--maculata } CHAMAESYCE --serpens chamissonis SCLEROPHYLLAE --mesembryanthemifolia } arnottiana } I atrococca GYMNADENIAE _q celastroides ~multiformis FI6. 14. Cladogram of Chamaesyce. Adams consensus of 10 equally fit implied weighted trees.

We prefer the use of implied weighting ported by our analysis. Allem and Irgang over equal character weighting because we (1975) and Subils (1977) opted not to main- believe that not all characters have equal ex- tain "Pleiadeniae" as constituted by Boissier planatory value (and therefore equal weights) (1862) and transferred some of its members and consequently that character weighting (C. selloi and C. setosa) to Hypericifoliae. based on their fit to tree topology is a logical However, our analysis shows that inclusion extension of parsimony (Goloboff, 1993a). of C. seUoi and C. setosa would make Hy- However, most of the conclusions we shall pericifoliae paraphyletic (Figs. 13, 14). draw can be made with the unweighted strict Beyond supporting most of the earlier no- consensus tree (Fig. 13) as well as the im- tions of phylogeny within Chamaesyce, there plied weighted Adams consensus tree (Fig. are two additional important points from the 14). Other than a few assertions as to rela- analysis. First, the Sclerophyllael tionships among one or more subsections ex- Gymnadeniae lineage is independent of the pressed in the primary literature, there are no comprehensive previous studies on the phy- Hypericifoliae/Chamaesyce lineage (Figs. 13, logeny of Chamaesyce. Koutnik (1987) 14). Second, "Pleiadeniae" is not a mono- grouped Gymnadeniae within Sclerophyllae, phyletic group and should not be recognized an idea supported by our analysis. Webster in formal classifications. Furthermore, based (1967) suggested that Acutae is basal within on implied weighting, C. potentilloides may the genus Chamaesyce, another idea support- represent an independent lineage from the ed by our analysis. Webster (1967) further other members of "Pleiadeniae" (Fig. 14). suggested that "Pleiadeniae" is basal within This issue will need to be addressed with fur- the genus Chamaesyce, an idea partially sup- ther studies using more characters. 166 BRITI'ONIA [VOL. 49

Artificial key to the hemicryptophytic species of Chamaesyce from cerrado vegetation 1. Verticils present; cyathia in a pleiochasial or dichasial superinflorescence (pseudomonopodial in late season); seeds smooth; plant usually glabrous or sparsely pilose; leaves strictly entire. Central Brazil through northern Argentina, Uruguay, Paraguay, and Bolivia. C. potentilloides 1. Verticils absent, all leaves strictly opposite; cyathia in dichasial or pseudomonopodial positions; seeds rugose-punctate; plant usually pubescent; leaves entire to serrulate. 2. Cyathia strictly solitary. 3. Leaves serrulate to crenulate; cyathia strictly proximal, borne among scale-like cataphylls or the first few foliage leaves (distal regions of stems soon becoming strictly vegetative); peduncles usually 12-20 mm long. Goids and Rio Grande do Sul, Brazil, and southeastern Paraguay. C. nana 3. Leaves strictly entire; cyathia distal, borne among foliage leaves; peduncles usually <5 mm long. 4. Stems usually 15-25 cm long, stems and cyathia long white hirsute-velutinous; appendages smooth. Goids and Minas Gerais, Brazil. C. viscoides 4. Stems usually <10 cm long, stems and cyathia short crispate-pubescent to short velutinous; appendages with papillate protuberances. Very rare, Bahia, Brazil. C. tamanduana 2. Cyathia solitary and in glomernles of 2-12 per node (some late-season plants may exhibit only solitary cyathia). 5. Cyathial appendages truncate, yellow, erect, crispate-pubescent; leaves often entire; stems sparse- ly branched, often woody at the base. Minas Gerais and Goi~is, Brazil. C. setosa 5. Cyathial appendages reniform, white to rarely pink or yellowish, perpendicular to rim of cy- athium to erect, glabrous; leaves usually serrulate; stems often highly branched. Argentina, Paraguay, Uruguay, Rio Grande do Sul, Brazil. C. selloi

Chamaesyce nana (Klotzsche & Garcke) rulate, persistent; foliage leaves largest at M. P. Simmons & W. J. Hayden, comb. mid to upper stem; blades short ovate to nov. (Figs. 1E 6F) ovate-elliptical to ovate-lanceolate, often weakly falcate, 9-27 x 6-9(13) ram, mid- Anisophyllum nahum Klotzsch & Garcke in Abh. K. Akad. Wiss. Berlin 32. 1859. Euphorbia chama- rib and often blade short white crispate-pu- errhodos Boiss. in Centuria Euphorbiarum 3. bescent (sometimes glabrous or hirsute-ve- 1860. Chamaesyce chamaerrhodos (Boiss.) Cro- lutinous); adaxial surface drying pale to izat, J. Arnold Arbor. 24: 184. 1943. TYPE: BRA- darker green; abaxial surface light brown or ZIL. Sellow 3131. (LECTOTYPE (designated here), MO; ISOLECTOTYPES, K, U, W-2 sheets). lighter green than adaxial surface; base Euphorbia Chamaerodos [sic] Boiss. var. hirsuta oblique; margin serrulate; apex acute; peti- Chodat & Hassl., Bull. Herb. Boiss. (str. 2) 5:681 ole 1 mm long; stipules connate, rarely with (616). 1905. TYPE: PARAGUAY: In campis com- distinct collar of tissue adnate with cata- bustis in regione cursus superioris fluminis Apa, Hassler 8498 (BM, JEPS, NY). phylls, persistent, narrow to broadly trian- Euphorbia macrorrhiza Glaziou non C. A. Mey. ex gular, 0.4-1.3 x 0.1-0.8 mm at base, gla- Ledeb., Mem. Soc. Bot. France 3: 637, nom. nud. brous to short crispate-pubescent (to few Aerial stems per rootstock varying sea- uniseriate multicellular hirsute-velutinous), sonally, slender, ascending, degree of not tufted hirsute-velutinous adaxially. Cy- branching varying seasonally, up to 30 cm athia solitary, borne on early-season dicha- long (see below), short-crispate (sometimes sial or pseudomonopodial stems, subtended hirsute-velutinous); stem trichomes unise- by cataphylls or the most proximal 1-3 riate, multicellular, white (sometimes yel- pairs of vegetative leaves; peduncles (3)12- lowish), 0.1~).25 mm (to ca. 1 mm) long. 20(25) mm long; involucre campanulate, Early season stems many from rootstock, externally yellowish (white-yellow) short floriferous, highly branched, 3-4(6) cm crispate-pubescent (hirsute-velutinous), long; late-season vegetative stems arising (1)1.2-1.6(2) X 1.3-2.3 mm at mouth; pri- by proliferation from some early-season- mary lobes 5, weakly keeled, entire, white- flowering stems, 1 to several per rootstock, (sometimes yellowish-) ciliate; glands 4, sterile, sparsely branched, 4-10(30) cm transversely oblong, drying light to dark long, to 1.8 mm diam. at base. Leaves ei- brown, not obviously pubescent on inner ther cataphylls or foliage leaves, strictly op- side, conspicuously stalked; gland bases posite; cataphylls scale-like, entire or ser- narrow, crispate-pubescent; appendages ob- 1997] SIMMONS '& HAYDEN: EUPHORBIACEAE 167

60 o 55 ~ /50 ~ ,2 4"5 ~ ~40 ~

o%

i0 o

C. nana

0 C. tamanduana /

,,,35~ C. viscoides

I I I I f I

FIG. 15. Distribution of Chamaesyce nana, C. tamanduana, and C. viscoides.

ovate to rounded, 1-1.6(1.8) mm long, pla- long), uniseriate, multicellular, yellow (to nar, perpendicular to rim of cyathium to white). Seed subovoid, _+ tetragonal, 1.5- erect, glabrous, weakly repand, white 1.7(2) x 1.1-1.3 mm, rugose-punctate, (sometimes pink). Staminate flowers ca. brown, often with thin white surface at hi- 25-30. Pistillate flower with gynophore to lum; base truncate. 2 mm long at maturity, densely crispate-pu- Habitar--Cerrado and grasslands. bescent (sometimes short uniseriate multi- Distribution.--In Brazil in Goi~is and cellular hirsute-velutinous); ovary yellow central through western Rio Grande do Sul (sometimes white or yellowish) short and southeastern Paraguay (Fig. 15). (sometimes long) crispate-pubescent; styles Phenology.--Available evidence indi- (0.6)1(1.2) mm long, glabrous (sometimes cates cyathia present from early September crispate pubescent), connate basally, lower through late February. portion erect, bifid for of length, tips Specimens examined. BRAZIL. Without specific lo- recurved; stigmas thin or somewhat clavate. cality: Sellow s. n. (K, MO, U, W-2 sheets); St. Hilaire Capsule crispate-pubescent, (2.3)2.6-2.7 X 780 (A-fragment ex P, mixed collection with C. viscoi- (2.5)3-3.3 mm; trichomes short (sometimes des). Goi~is: Between Planaltima and S~o Jose de Alianga 168 BRITTONIA [VOL. 49 on the DF 17, Ratter et al. 4506 (UB); "le plateau cen- hairs, no other features distinguish the va- tral," Glaziou 22085 (G-mixed collection with C. poten- riety. All three specimens were collected in tilloides, MO). Rio Grande do Sul: Gaudichaud 1705 (F-fragment ex P); 1 km da Barragen do Itu-S~o Fran- southeastern Paraguay where more typical cisco de Assis, AUem et al. ICN 29885 (ICN); S~o Borja, specimens were also collected. Because of Allem et al. ICN 29884 (ICN). Soledade: Rio Jacuhysin- the intermediate specimen, common geo- ho, Bornmiiller 639 (JE). graphical locations, and lack of further dis- PARAGUAY. Alto Paran~i: Reserva Biologica Tati Yupi, Marmori 1274 (CTES). Amambay: Sierra de tinguishing characters, we do not believe Amambay, Cabecera Rio Aguidaban, Rojas 6354 (A). that this variety should be recognized. Caagua~: Near Caaguazfa, Hassler 9294 (BM, F, GH, There are three details in which our mor- MO, NY, S); near IgatiroS, Yerbalium de Maracayu, Hass- phological description for C. nana differs ler 4675 (BM, GH, JEPS, MO, NY, S). Concepeirn: from that of Boissier (1860) and Mueller Upper Rio Apa, Hassler 8498 (BM, JEPS, NY). Para- gum'i: Carapegua, Rojas 3352 (A). Misiones: Santiago, (1874). Boissier (1860) cited glands num- Estancia "La Soledad," Pedersen 6548 (NY). Without bering four or five. Mueller Argoviensis further locality data: Est. Aomonia, Regnell 1970 (S); (1874) concurred and further indicated two Lapyta, Jorgensen 4672 (C, E MO-mixed collection with appendages to be distinctly larger. However, C. Selloi, NY-2 sheets, S, SI, US). we saw only one cyathium on the several When Chamaesyce nana was first named Sellow specimens examined that might have as a species of Anisophyllum (Klotzsch, five glands, though we are not certain. On 1859), an unnumbered Sellow specimen all other specimens we saw cyathia with was cited as its type. However, some Sel- only four glands. As for gland size asym- low collections of this plant bear the col- metry cited by Mueller Argoviensis, this lection number 3131, notably, photographs pattern was not evident in any of the spec- of a type at B, now destroyed but most like- imens examined. Glands on each cyathium ly seen by Klotzsch, and also a specimen at appeared to be relatively equal in size, MO. We have no reason to believe that the though occasionally there was some minor Sellow collections of this plant, whether variation. Both Boissier and Mueller Ar- numbered or not, constitute more than a goviensis cited the capsule as flattened- single collection. At any rate, the sheet at keeled, and neither mentioned distal thick- MO, which consists of four separate plant- ening of the stigmas. We interpret the "flat- lets and a packet bearing capsules and very tened" characterization of the capsules as immature seeds, serves well as a lectotype an artifact of the very wide capsules being because of its comparatively abundant ma- pressed somewhat flat during specimen dry- terial and is numbered consistently with ing. Though some stigmas are thin, many material most likely studied by Klotzsch. are thickened and somewhat clavate. Upon transferring Klotzsch and Garcke's Geographically, Chamaesyce nana ap- species of Anisophyllum to Euphorbia, pears to consist of two disjunct populations, Boissier (1860) coined the name Euphorbia one in Goi~is, Brazil, and one in southeastern chamaerrhodos, because of the existence of Paraguay through Rio Grande do Sul, Brazil. E. nana Royle, a different species. We do not know of any reason for this pe- Euphorbia Chamaerodos [sic] var. hir- culiar distribution. In comparing the three suta is herein treated as a synonym of Cha- specimens from Goi~is with the other speci- maesyce nana. Besides the type specimen mens from Paraguay and Rio Grande do Sul, of this variety (Hassler 8498), Rojas 3352 there were no qualitative differences and is the only other specimen examined that only minor quantitative differences. We ob- has uniseriate multicellular hirsute-veluti- served cyathia and appendages appreciably nous hairs on the stems, leaves, stipules, cy- larger than average in Glaziou 22085 and athial involucres, and pistillate gynophores. Ratter 4506 from Goi~is, but they are not More-typical specimens have crispate hairs separable in size from the full range evident in the above-mentioned areas. However, an in Paraguay and Rio Grande do Sul. Ratter intermediate specimen, Marmori 1274, has 4506 is somewhat abnormal for the species both crispate hairs and weakly velutinous because it has short hirsute hairs instead of uniseriate multicellular hairs. Besides the crispate hairs and lacks crispate hairs on the uniseriate multicellutar hirsute-velutinous short bases of the cyathial glands. 1997] SIMMONS ~& HAYDEN: EUPHORBIACEAE 169

CHAMAESYCE POTENT1LLOIDES (Boiss.) Cro- brous to short-pubescent, (0.5)0.6-1.3(2) • izat (Figs. 1A, B, 6C, D). (0.6)1-2(2.6) mm at mouth; primary lobes 5 (to 8), keeled, entire, white ciliate; glands 4 Chamaesyce potentilloides (Boiss.) Croizat, J. Ar- (to 7), round to reniform or vestigial, con- nold Arbor. 24: 184. 1943.--Euphorbia potentil- loides Boiss. in Centuria Euphorbiarum 3. 1860. cave, minutely pitted, drying yellow to tan SYWrYPES (n.v.): BRAZIL, Goi~is, Loco Chapadas (green), appendiculate, bome on a short base; de San-Marcos, Riedel s.n. (LE); Lund s.n. (G). gland bases pubescent; appendages reniform Anisophyllum caecorum Klotzsch & Garcke in Abh. to oblong, 0.1-1(2.1) mm long, planar, per- K. Akad. Wiss. Berlin 38. 1859, nom. nud. Eu- phorbia caecorum Mart. ex Boiss. in DeCandolle, pendicular to rim of cyathium (or somewhat Prodromus 15(2): 51. 1862. SYwrvPES: BRAZIL, erect) glabrous, parallel veined, repand to without specific locality, Sellow s.n. (BR, K, LD, erose, white to yellow (sometimes pink to W-2 sheets); Minas Gerais, Widgren s.n. (LD, S- maroon or green). Staminate flowers ca. 50. sheet without additional collection, S-specimen at Pistillate flower with gynophore to 2.6 mm bottom of sheet shared with Regnell s.n.); BO- LIVIA, Chiquitos, d'Orbigny 944 (A, E both are long at maturity, glabrous; ovary glabrous to fragments ex P). Chamaesyce caecorum (Mart. ex pubemlent; styles 0.4 mm long, glabrous to Boiss.) Croizat, J. Arnold Arbor. 24: 187. 1943. pubemlent, connate basally, promptly spread- Euphorbia albiflora Taub., Bot. Jahrb. 21: 442. ing, bifid for 1/2 of length; stigmas clavate. 1895. TYPE: BRAZIL, Goi~ts, Monte Morro do Capsule essentially glabrous, broadly ovoid, Salto, Ule 3054 (n.v.). 1.8-2.6 • 2-2.6(3.3) mm. Seed subovoid, _+ Aerial stems one to many per rootstock, tetragonal, 1.2-1.5(1.8) • 0.7-1.1 mm, usually annual (some bases may winter over), smooth overall but minutely pitted, brown; slender, erect, unbranched below the inflores- base truncate, concave. cence, (5)10-30(35) cm long, 0.4-1.6 mm Habitat. Primarily open cerrado, often diam. at base, glabrous to sparsely pilose or in areas exposed by recent fires and with a variously pubescent; stem trichomes uniseri- stony, sandy, or clay substrate, also open ate, multicellular, white (sometimes brown), grasslands, early successional woodlands, highly variable in length. Leaves variable in and disturbed areas. Altitude of 300-1350 m. size and shape depending on position, rang- Distribution.--In Brazil from ca. 12~ in ing continuously from persistent or deciduous Matt Grosso, Goi~is, and Bahia, through cataphylls to foliage leaves and cyathophylls, eastern Matt Grosso do Sul, Minas Gerais, largest at midstem or base of flowering re- S~o Paulo, Paran~i, and Rio Grande do Sul; gion, in verticils of (2)3(5) below, strictly op- west to Santa Cruz, Bolivia, eastern Para- posite and distichous above; blades ovate to guay, and Misiones, Argentina; south to oblong to lanceolate to linear, (3)10-30(45) northem Corrientes, Argentina, and north- • (1)1.5-6(10) mm, glabrous to sparsely pu- ern Uruguay (Fig. 16). No specimens seen bescent; adaxial surface drying pale to dark from Santa Catarina, Brazil. green; abaxial surface somewhat lighter; base Phenology.--Flowers and fruits primari- acute, obtuse, truncate, or weakly cordate, ly August through December, often into symmetrical to somewhat oblique; margin April, occasionally throughout the year in entire, somewhat thickened; apex acute, often the northern portion of the range. cuspidate; petiole (0.3)0.6-1.3(2.3) mm long; Representative specimens examined. ARGENTINA. midrib occasionally purple, depressed adaxi- Corrlentes: Estancia Garruchos, Pedersen 2881 (C, ally, protruding abaxially; stipules connate, US). Misiones: Ap6stoles, lbarrola 1127 (A, NY); persistent, narrowly to broadly triangular, Lorteo, Crovetto 9796 (CTES); Posadas, Ekman 512 acute, 0.3-0.5(1) mm long, entire or deeply (G, LD, S, US). cleft to base, serrulate, sparsely to densely BOLIVIA. Santa Cruz: Santiago de Chiquitos, Cut- ler 7034 (A, US); Prov. Sara, Buena Vista, Steinbach hirsute adaxially. Cyathia borne continuously 5172 (F, GH, MO, NY), Steinbach 6323 (A, G). on aerial stems on pleiochasial (initially) or BRAZIL. Without specific locality: Megaponte, dichasial (later) or pseudomonopodial (late Pohl 948 (W). Bahia: Aracatu, Harley et al. 15025 season) axes; intemodes decreasing progres- (K, MO, NY, U, US); Espigfio Mestre, Anderson et al. 36575 (NY), Anderson et al. 36896 (MO, NY, UB). sively from ca. 25 to 2.6 mm; peduncles 0.6- Distrito Federal: Aparecida da Silva & Azevedo 990 1.6(12) mm long; involucre campanulate (to (DAV), Cobra & Oliveira 215 (DAV), Heringer s.n. hemispherical or urceolate), externally gla- (UB 48613), Irwin et al. 8077 (MO, NY), Irwin et al. 170 BRITTONIA [VOL. 49

60 ~ 55 ~ 45 ~ 40 ~

Qo

./ eL

/ 0 0

0 0 j'

o 0

C. potentilloides

I I I I I I 500 km

FIG. 16. Distribution of Chamaesyce potentilloides.

8380 (MO, NY), Irwin et al. 8655 (K), Maguire et al. ing s.n. (GH); Silo Joao d'el Rey, Malme 1243 (S). 57076 (LD), Philcox & Onishi 4285 (K). Goi~is: Bur- Paran~i: Jaguariaiva, Dusen 10675 (AFS, E GH, NY, chell 7021 (B, K), Glaziou 22087 (A, B, BR, G, S, S), Dusen 16450 (MO, NY, S); Municipio Lapa, US); Chapada dos Veadeiros, Dawson 14584 (F, RSA); Hatschbach 1002 (US); Palmeira, Hatschbach 20161 Niquelandia, Irwin et al. 35025 (MO, NY); Serra do (JEPS, MO). Rio Grande do Sul: Cerro Armor-Liv- Caiap6, Irwin & Soderstrom 6953 (F, NY); Serra dos ramento, Porto et al. 1834 (ICN); Pieada do Padre, Cristais, Irwin et al. 9921 (F-2 sheets, K, LD, UB), Adeliero 280 (F); S~o Vicente do Sul, Sorbal & Mar- Irwin et al. 9924 (E, F, K, NY, UB); Serra dos Pirineus, chiori 4549 (ICN); Tupancireta, Normann & Gianluppi Irwin et al. 18684 (E MO, NY). Mato Grosso: Braqo, 552 (ICN). S~o Paulo: Capao Bonito, Dusen 15027 Baldwin 3026 (US); Cachoeira Furada, Prance et al. (GH, S); Municipio de Moji--Guaqu, Eiten & Eiten 18850 (NY, U, US); Suia-Missu River, Philcox et al. 5078 (NY, US); Munic/pio de S~o Jos6 dos Campos, 3262 (NY, UB). Mato Grosso do Sui: Barra do Gar- qas, Eiten & Eiten 8484 (US); Campo Grande, Archer Mimura 131 (NY, URV). & Gehrt 148 (GH, NY, URV, US); Xavantina, Irwin PARAGUAY. Amamhay: Sierra de Amambay, Ro- & Soderstrom 6382 (NY); 75 km N of Xavantina, Ir- jas 6339 (A, BAF). Caaguazti: Yerbalium de Mara- win & Soderstrom 6704 (C, E MO, NY, U, US); 250 cayu, Hassler 4181 (BM). Without further locality km NNE of Xavantina, Eiten & Eiten 8533 (US). Mi- data: Cerros de Tobaty, Hassler 6110 (E GH, JEPS, nas Gerais: Asemp 25933, Weddell 1091 (A-fragment NY, S). ex P); Caldas, Lindberg 429 (BR, S), Lindberg 649 URUGUAY. Rivera: Rivera, Berro 1796 (MVFA), (BR), Regnell 1407 (BR, S, US); Lagoa Santa, Warm- Berro 4814 (MVFA); near Galgo, Herter 271 (LD). 1997] SIMMONS ~& HAYDEN: EUPHORBIACEAE 171

The epithet "caecorum" is the earlier Irwin et al. 9924, but intergradation from and much more widely used of the names this form to more-typical forms (with applied to this taxon in the past. Unfortu- leaves similar to Fig. 17E) is shown by Ir- nately, the publication ofAnisophyllum cae- win et al. 18684 and Irwin et al. 8077. corum by Klotzsch and Garcke was based A dwarf form consists of plants with high- on the transfer of an unpublished name that ly branched stems usually less than 8 cm in had been used by Martius. When Boissier height bearing very narrow, linear leaves 12- published the name legitimately in the 18(27) mm long and only 1-1.5 nun wide Prodromus, he had already named what we (Fig. 17C), and cyathia with large oblong ap- recognize as the same species, Euphorbia pendages 1.3-2.3 mm long. The most ex- potentilloides, two years earlier. treme specimen is Irwin et al. 9921 in which Although we have seen neither of the two the plants form dense mounds about 5 cm syntypes of Chamaesyce potentilloides, we tall. The stems and intemodes can become are confident that Chamaesyce caecorum is extremely elongated to 26 cm, as per Macedo the same entity. This judgment is based on 3729 and Maguire et al. 57076. Intergrada- analysis of the original descriptions of both tion with more-general forms is shown by Ir- taxa, Boissier's (1866) excellent lithograph win et al. 8655 and 8380. of C. potentilloides, and an early compari- There are plants of normal height (great- son of the two taxa (Mueller Argoviensis, er than 10 cm) with very narrow, linear 1874). Mueller Argoviensis sought to dis- leaves which are similar to the dwarf form. tinguish the two by supposed differences in However, the leaves are larger (14 X 1 mm overall color and in structure of the invo- to 35 x 2 mm) (Fig. 17D), and the plants lucre, styles, and fruit. Given the enormous have small cyathia with very small reniform and continuous range of variation evident appendages 0.1-0.3 mm long. The most ex- in collections made since the last century, treme specimen of this linear leaf form is however, none of Mueller Argoviensis's Dusen 16450. Intergradation with more- distinctions can be upheld. typical forms is shown by Dusen 15027 and On the basis of the published description, Eiten & Eiten 5078. we note that all but one of the features of Plants with wide, oblong leaves (Fig. Euphorbia albiflora fall easily within the 171) in apical clusters of closely spaced range of morphological variation observed nodes on short stems are an uncommonly for C. potentilloides. Appendages of the found form. An extreme specimen is Her- type, Ule 3054, are described as 3.5 mm long, larger by one-third than any noted in inger s.n. Intergradation from this oblong C. potentilloides. We have not seen the type leaf form with more typical forms is shown to verify the reported appendage dimen- by Archer & Gehrt 148 and Philcox & On- sions but feel this minor discrepancy insuf- ishi 4285. ficient to prevent placement of E. albiflora Plants of another form have very long in synonymy with the highly variable C. lanceolate leaves (Fig. 17A). The most ex- potentilloides. treme specimen is Irwin & Soderstrorn Chamaesyce potentilloides is a remark- 6953. Irwin et al. 35025 and Irwin & Sod- ably variable species with extreme forms erstrom 6382 demonstrate intergradation that intergrade. Variability is more pro- from this lanceolate leaf form to more-gen- nounced in vegetative features than in re- eral forms. productive characters. We have observed There are plants with thick leaves that eight extreme forms, but none, in light of often resemble cataphylls in size and shape, present knowledge, merits formal taxonom- but are on widely spaced nodes (Fig. 17F). ic status. These plants also have cyathia with very A robust form consists of plants with small appendages, and the plants darken on very large, wide, almost cordate leaves drying. The most extreme specimen is Phil- (Fig. 17H), often with cyathia and append- cox et al. 3262. Specimens that intergrade ages larger (0.7-1.7 mm long) than usual. with more typical forms have longer and/or The most extreme specimen of this form is wider leaves and/or shorter internodes, for 172 BRITrONIA [VOL. 49

C )

E

B ! I lcm "t

FIG. 17. Diversity of leaf shape in Chamaesycepotentilloides, from dried pressed material (see the discussion under C. potentilloides for vouchers). A. Lanceolate leaf form. B. Late-season form. (2. Dwarf form. D. Linear leaf form. E. Common leaf of C. potentilloides. F. Cataphyll leaf form. G. Early season form. H. Robust form. I. Oblong leaf form. example Eiten & Eiten 8484 and Irwin & but pseudomonopodial above with seemingly Soderstrom 6704. axillary cyathia present toward the apex. The Another form consists of plants collected most extreme specimen is Dawson 14584 in early spring (August and September) (RSA) with a distinctly woody, knotted pe- with short stems and leaves similar in shape rennial aerial stem. Other specimens include though slightly larger than cataphylls (Fig. Anderson et al. 36575 and 36896. 17G). Examples of this early-season form None of these forms shows differentia- include Eiten & Eiten 8533, Asemp 25933, tion in seed, leaf anatomy, pollen, or cy- and Maline 1243. athium structure characters. The variation is A late-season form consists of plants col- essentially restricted to characters of gross lected in midsummer through fall (late De- morphology such as overall plant size, leaf cember through April). These older stems shapes and sizes, and shapes and sizes of have some secondary growth and bear op- various cyathium structures. Some forms posite distichous cyathophylls (Fig. 17B). show no geographical cohesion----e.g., the Stems are dichotomously branched below, forms characterized by oblong leaves, lan- 1997] SIMMONS & HAYDEN: EUPHORBIACEAE 173 ceolate leaves, and the early- and late-sea- velutinous; adaxial surface drying light to son forms. The robust and dwarf forms are dark green, occasionally with a central red- geographically restricted to the region dish spot; abaxial surface lighter; base dis- around Distrito Federal and adjacent Goi~is tinctly oblique; margin entire to serrulate; (Brazil), but typical forms also occur in the apex acute; petiole 1-2 mm long; stipules same area. The long internode form occurs narrow triangular, 0.4-1.6 mm long, some in Mato Grosso, Mato Grosso do Sul, and strigose abaxially, not tufted hirsute adaxi- western Goi~is of Brazil, also in the same ally. Cyathia on distal portions of stems, general areas as more typical forms. The solitary or clustered in glomerules of 1- linear leaf form is found throughout the en- 3(6), in pseudomonopodial (sometimes di- tire southern range including Argentina, chasial) positions, appearing terminal or ax- Uruguay, Paraguay, and Rio Grande do Sul illary; peduncles 1.3-3.3 mm long; invo- (Brazil), but occurs intermixed with more- lucre campanulate or widely campanulate, typical forms in Bolivia and, in Brazil, Pa- green to red, externally densely white to ran~i and S~o Paulo. Population studies are yellow or pink crispate-pubescent, (1)1.2- necessary to address whether the linear leaf 1.6(2) x (1.1)1.3-1.6(2.2) mm at mouth; form should be treated as a distinct variety. primary lobes 5, often distinctly keeled, en- tire or serrulate, whitish ciliate; glands 4, CHAMAESYCE SELLOI (Klotzsch & Garcke) round to transversely oblong, drying dark Croizat (Figs. 1D, 6B). green to brown, densely ciliate; gland bases Chamaesyce setloi (Klotzsch & Garcke) Croizat, J. densely white to pink crispate-pubescent; Arnold Arbor. 24: 184.--Anisophyllum selloi appendages reniform to reniform-auricu- Klotzsch & Garcke in Abh. K. Akad. Wiss. Berlin late, 0.4-0.6(1) mm long, planar or some- 32. 1859. Euphorbia selloi (Klotzsch & Garcke) Boiss. in DeCandolle, Prodromus 15(2): 50. 1862. what convolute, perpendicular to rim of cy- TYPE: BRAZIL. Sellow s.n. (LECTOTYPE (desig- athium to erect, glabrous, repand, white nated here), BR; ISOLECTOTYPES, BM-specimen (sometimes yellowish or pink), rarely un- on right, E GH, S, U, US, W-2 sheets). equal (to somewhat larger). Staminate flow- Euphorbia Hassleriana Chodat, Bull. Herb. Boiss. (S6r. 2) 1:399 (93). 1902 ("1901"). TYPE: PAR- ers ca. 25-35. Pistillate flower with gyno- AGUAY: Without specific locality, Hassler 1228 phore to 1.7 mm long at maturity, long (G). white to yellow or pink crispate pubescent; Euphorbia hebegyne Pax & K. Hoffm., in Emrich, ovary long white to yellow or pink crispate Revista Sudamer. Bot. 4: 83. 1937. TYPE (n.v.): pubescent; styles 0.6-1 mm long, glabrous BRAZIL: Rio Grande do Sul: Porto Alegre, Caixa d'Agua, Emrich 11. or yellow crispate-pubescent at base, con- Chamaesyce Selloi var. brevisemina Croizat, J. Ar- nate basally, lower portion erect, bifid for nold Arbor. 24: 184. 1943. TYPE: ARGENTINA: %--2,5 of length, tips recurved; stigmas ta- Entre Rios: Concordia, Burkart 822 (A). pered or weakly thickened. Capsule cris- Euphorbia selloi var. setosa sensu Subils (Kurtziana 10: 147. 1977), non Boissier. pate-pubescent, 2.2-2.5 • (2)2.2-2.5 mm; trichomes long, uniseriate, multicellular, Aerial stems 1 to many per rootstock, ap- yellow. Seed subovoid, +__ tetragonal, 1.3- parently annual, slender, erect to weakly as- 1.6 x 0.8-1 mm, rugose-punctate, brown, cending, sparsely to highly branched, often with thin white surface at hilum. (7)10-25(38) cm long, 0.8-1.5 mm diam. Habitat.--Grasslands and dry, rocky at base, sparsely to densely crispate and hir- countryside. sute-velutinous or only crispate; stem tri- Distribution.--Southeastern Paraguay chomes uniseriate, multicellular, often with through Rio Grande do Sul of Brazil, north- yellowish or reddish deposits at crosswalls, western Uruguay, and northern Entre Rfos, 1.3-4 mm long. Leaves either cataphylls or eastern Chaco, Corrientes, and southern Mi- foliage leaves, strictly opposite; cataphylls siones of Argentina (Fig. 18). smaller, ovate, serrulate, essentially persis- Phenology.---Flowers and fruits present tent; foliage leaves largest at mid to upper year-round. stem; blades ovate to lanceolate, weakly falcate, (12)16-30(45) • 4-9 ram, sparsely Representative specimens examined. ARGENTINA. to densely white crispate-pubescent and/or Chaco: Benitez, Schulz 1531 (U); Rio de Uro, Nicken 174 BRITTONIA [VOL. 49

60 ~ 55 ~ 45 ~ 40 ~

0 0~- 00

"k

C. selloi

C. setosa

I I I I I 500 km

FIG. 18. Distribution of Chamaesyce selloi and C. setosa.

85 (A). Corrientes: Conception, Arbo 304 (CTES), PARAGUAY. Without specific locality: Hassler 1228 Krapovickas & Cristobal 11642 (CTES, JEPS, US), (G), Jorgensen 4336 (A, NY, S). Without additional lo- Pedersen 8090 (C, L, NY, US); Ituzaingo, Lourteig et cality data: Prairies de Dona-Juana, Balansa 1678 (G, al. 2951 (JEPS, MO); Paso de los Libres, Schinini S); Ybrimi, Montes 12935 (CTES, LPS). 7633 (CORD); Saladas, Schwarz 9550 (LIL); San Mi- URUGUAY. Without specific locality: Cerro de las guel, Krapovickas et al. 24777 (G, GB), Schinini et al. Palmas, Berro 1448 (K, MVFA). Paysandti: Rio Uru- 8313 (CTES, G, JEPS); Santa Catalina, Hunziker 5779 guay, Chapicuy, Rosengurtt 3225 (A-2 sheets, HAS, (A). Entre Rios: Concordia, Burkart 822 (A), Castel- MO, U, US); Rfo Uruguay, north of Rfo Quequay, Ro- lanos 271 (BA), Gamerro 1116 (LPS). Misiones: sengurtt B-3303 (A). Rivera: Flossdorf 5209 (A). Ap6stoles, Renvoize 3082 (NY, US); Candelaria, Kra- povickas et al. 15444 (CTES); Posadas, Ekman 511 Klotzsch and Garcke typified Anisophyl- (G, LD, NY, S, US). Santa Fe: Reconquista, Burkart lum selloi with two collections, those of 5790 (A). BRAZIL. Without specific locality: Pohl s.n. (K), Sellow and Pohl. The Pohl specimen is Sellow s.n. (BM-specimen on right, BR, F, GH, S, U, somewhat problematic. Our studies have US, W-2 sheets), Sello 170 (A-fragment ex G). Rio uncovered only a single sheet (at K) bearing Grande do Sul: L. Gomen, Bornmitller 252 (G, GH, no collector's name that we nevertheless JE, M, WU); Porto Alegre, Emrich 28 (U), Maline 487 (S), Rambo 37860 (B, S, W), Schultz 104 (ICN); S. suspect was collected by Pohl. This judg- Leopoldo, Schmitt 47474 (B). ment is based on comparison of the labels, 1997] SIMMONS &HAYDEN: EUPHORBIACEAE 175

ink, and handwriting of the specimen at K ly perceive no basis for distinguishing Pax with two Pohl collections of C. viscoides: and Hoffmann's taxon. Pohl & Burchell s.n. at G and Pohl 2179 Chamaesyce selloi var. brevisemina Cro- at W. In contrast, the Sellow specimens cit- izat is another problematic taxon. Croizat ed by Klotzsch and Garcke are clearly la- based this variety on seed morphology of beled and widely distributed in herbaria; three specimens--Burkhart 822 (the varie- from these the sheet at BR has been chosen tal holotype), Rosengurt B-3303, and Hun- as lectotype because of its abundant mate- ziker 5779--that he compared with Sellow rial, including a rootstock and immature 170, mistakenly believing the latter to be seed. the holotype of the species. According to Chamaesyce selloi is a markedly variable Croizat, var. brevisemina has ovoid seeds species, a fact that has contributed to the with a smooth raphe, in contrast to suppos- proliferation of names that we have syn- edly typical selloi with triangular-acuminate onymized above. For the first of these, Eu- seeds and an impressed raphe. Reexamina- phorbia Hassleriana, Chodat (1901) thor- tion of these specimens at A has failed to oughly described vegetative structure but yield support for the proposed variant. No provided only a cursory and somewhat con- seeds could be found in the packets of fusing comparison of its cyathia with those Burkhart 822 nor Hunziker 5779. The spec- of C. selloi and C. setosa. Chodat focused imen of Rosengurt B-3303 has mature on the number of cyathia per node and the seeds, but these seeds are identical to those angle of the "glands," which we interpret found throughout C. selloi. Finally, the to mean the appendages of the glands. The specimen of Sellow 170 bears only a single type specimen, Hassler 1228, has one or immature seed, suggesting that Croizat two cyathia per node and appendages that based var. brevisemina on an erroneous comparison of mature and immature seeds. are perpendicular to the rim of the cy- Chamaesyce selloi vat. brevisemina has athium, features that we find to be fully been previously synonymized with Euphor- consistent with our concept of C. selloi, a bia hassleriana by Subils (1977). concept that is probably somewhat broader We believe Subils (1977) misapplied than Chodat's. In comparison, Chamaesyce Boissier's var. setosa. The specimens that setosa, with most cyathia in glomerules and she cited are discordant with our under- erect appendages, is clearly distinct. Subils standing of Boissier's variety and are better (1977) accepted Chodat's species, but her referred to typical C. selloi. treatment of this taxon reveals a number of Variation within Chamaesyce selloi re- inconsistencies. Specimens identified as E. veals considerable intergradation between hassleriana by Subils possess appendages weakly definable forms. One form may be that range from erect to perpendicular, often characterized by a rather lax habit, short with both extremes on the same plant. ovate-lanceolate leaves, and whitish pubes- Moreover, her illustration of this species has cence including relatively few velutinous erect appendages whereas her key and de- hairs on stems and leaves; this form is scription indicate appendages to be horizon- found throughout the range of the species tal. but is rather infrequent in Misiones, Argen- We follow Rambo (1960) and Allem and tina, and Paraguay. Schinini 7783 is a good Irgang (1975) in treating Euphorbia hebe- example of this lax form. Another form has gyne as a synonym of Chamaesyce selloi. an erect habit, long-lanceolate leaves, and Although we have not seen the type, the yellowish pubescence including more description and excellent illustration in Em- densely velutinous hairs on stems and rich (1937) purport this taxon to differ in leaves; this form is frequent in Misiones, its possession of subentire, linear leaves and Argentina, and Paraguay. The erect form is non-capitate clusters of cyathia. However, illustrated by Ekman 511. Specimens tran- we have found leaf width and cyathium sitional between these extremes are es- number per node to vary considerably and pecially abundant in Rio Grande do Sul, independently in C. selloi, and consequent- Brazil. 176 BRITI'ONIA [VOL. 49

Chamaesyce setosa (Boiss.) M. E Sim- er portion erect, bifid for */3-~A of length, tips mons & W. J. Hayden comb. nov. (Figs. recurved; stigmas either tapered or clavate. 1E, 6E) Capsule crispate pubescent, 2.2-2.6(3) x 2.5-2.8(3) mm; trichomes long, uniseriate, Euphorbia Selloi var. setosa Boiss. in DeCandolle multicellular, yellow. Seed obovoid, _+ tetrag- Prodromus 15(2): 50. 1862. Euphorbia setosa (Boiss.) Muell. Arg. in Martius Flora Brasiliensis onal, 1.5(1.7) • (0.9)1.1 mm, rugose-punc- 11(2): 672. 1874. SYNTYPES (n.y.): BRAZIL: tate, brown, often with thin white surface near Tijuco, Sellow s.n.; Mount Urubu, Pohl s.n. above hilum. (W). Goi~is: Riedel s.n. (LD, LE). Habitat.--Cerrado. Euphorbia villosissima Klotzsch pro syn. in Boissier (ibid). Distribution.--In Brazil in central to western Minas Gerais, into southeastern Aerial stems 1-4 per rootstock, apparently Gokis (Fig. 18). annual, slender, erect (to ascending), sparsely Phenology.--Flowers and fruits present branched, (7)20-30(55) cm long, 1.6-2 mm year-round. diam. at base, sparsely to densely short yel- low crispate and hirsute-velutinous; stem tri- Specimens examined. BRAZIL. Without specific chomes uniseriate, multicellular, often with locality: Pohl 1674 (K). Goi~is: Glaziou 22079 (C, G- mixed collection with C. viscoides); unknown collec- yellowish deposits at crosswalls, 0.6-2.8 mm tor, possibly Riedel s.n. (C); 10 km S of Campo long. I_~aves either cataphylls or foliage Alegre, Hatschbach 42251 (MO); 22 km NE of Ca- leaves, strictly opposite; cataphylls smaller, talao, Irwin et aL 25142 (DAV, MO, NY); Crominia- ovate, entire to serrulate, somewhat fuga- Mairipotaba, Brooks et aL 80 (MO); Paracuatu para Cristalina, Duarte 9292A (RB); Serra de Caldas, ceous; foliage leaves large at mid- to upper Hatschbach 38746 (DAV). Minas Gerais: Brade stem; blades ovate-lanceolate to elliptic-lan- 13579 (RB), Glaziou 19825 (C), St. Hilaire 595 (F- ceolate, (12)18-26(37) • 6-8(12) mm, fragment ex P), St. Hilaire 597 (F-fragment ex P); 3 sparsely to densely velutinous with white to km W of Cantoni, Irwin et al. 27209 (DAV, MO, NY); light yellow trichomes; adaxial surface dry- Ad Contendas, Martius s.n. (M); Estrada Curvelo- Corinto, km 40, Ferreira & Marques 34 (SP); 17 km ing olive-green to brown; abaxial surface SW of Gouv~ia, Anderson et aL 35615 (UB); Joaquim lighter; base distinctly oblique; margin entire Felicio, Silva et al. s.n. (F); Lagoa Santa, Barreto to serrulate; apex acute; petiole 1-2 mm long; 2599, 2600 (F), Warming 1662 (C-2 sheets), Warming stipules connate, deciduous, narrow-triangu- 1665 (C); Municfpio de Jaboticatubas, Joly et al. 4590 (SP), Samir et al 2847 (SP); Nova Ponte, Stehmann & lar, (0.6)0.8-1.2(1.3) mm long, some strigose Teixeira 1063 (SP); Paracatu, Glaziou s.n. (F-fragment abaxially, not tufted hirsute adaxially. Cyathia ex P), Irwin et al. 25967 (DAV, MO, NY); Paraopeba, on distal portions of stems, solitary or in Heringer 3874 (UB); Santa do Riacho, Forero et al. glomerules of (1)2-12(20), in pseudomono- 7994 (SP); Serra do Espinha~o, Hatschbach 27795 podial (sometimes dichasial) positions, ap- (MO); 23 km N of Uberaba, Goodland 3162 (UB); Cidade de Uberana, Regnell 111. 1049 (A, S-3 sheets, pearing terminal; peduncles (1)1.5-2(3) mm US-2 sheets); "Unicate," Irwin & Soderstrorn 5480 long; involucre campanulate to widely cam- (UB); V~irzea de Palma, Duarte 7456 (NY, RB). panulate, externally densely short yellow cris- pate-pubescent, (1)1.3-1.6 • (1.3)1.6- Chamaesyce setosa has long been poorly 2.3(2.5) mm at mouth; primary lobes 5, ob- understood. It was first proposed as a variety scurely keeled, entire or serrulate, yellowish of Euphorbia selloi by Boissier (1862). ciliate; glands 4, transversely oblong, drying Mueller Argoviensis (1874) elevated it to dark brown, ciliate; gland bases densely short species status within Euphorbia, but subse- yellow crispate pubescent; appendages short quent authors have questioned this disposi- truncate, 0.3-0.5(0.6) mm long, planar to tion or otherwise continued to confuse these convolute, erect, densely short yellow cris- two demonstrably distinct taxa. Herbarium pate-pubescent, entire, drying light yellow. specimens of these two taxa are frequently Staminate flowers about 30. Pistillate flower misidentified. The situation is exacerbated by with gynophore to 2.6 mm long at maturity, the problematic nature of historically and no- long yellow crispate-pubescent; ovary long menclaturally significant specimens. yellow crispate-pubescent; styles 0.6-1.1 mm Sellow specimens attributable to C. setosa long, short yellow crispate-pubescent have not been located in the course of this throughout their length, connate basally, low- study, nor has the sheet of Pohl s.n. reported 1997] SIMMONS & HAYDEN: EUPHORBIACEAE 177

TABLE III COMPARISON OF Chamaesyce setosa AND C. selloi

Character C. setosa C. selloi Leaves Dry darker Dry lighter Stems Often woody Rarely woody Stems Sparsely branched Highly branched Leaves Often entire Usually serrate Glomerules Terminal position Axillary and terminal positions Appendages Erect Perpendicular to rim of cyathium to erect Appendages Truncate Reniform Distribution Central Brazil Southern Brazil to northern Argentina

to be at W. However, Pohl 1674, from K, and Irgang's study was based on specimens matches descriptions of this taxon by Boissier from Rio Grande do Sul, none were of C. (1862) and Mueller Argoviensis (1874), who setosa. also cites this specimen. We do not know if On the other hand, Subils (1977) mis- Pohl 1674 is truly a duplicate of Boissier's applied C. setosa as an element of the Ar- syntype, but it is possible that Pohl's collec- gentine flora. She treated it as a variety of tion number was misplaced on the material E. selloi, with a range extending northward studied by Boissier. Likewise, Riedel s.n. to central Brazil. However, all Argentine could not be located at LD nor at LE. A spec- specimens cited by Subils prove to be C. imen at C, however, collected in Goi~is but selloi rather than C. setosa. without documentation as to the collector, is The qualitative characters in Table III perhaps a Riedel collection, judging by the readily distinguish Chamaesyce setosa from handwriting; it is possible that the specimen Chamaesyce selloi. is an isosyntype. We have also seen Regnell III. 1049 from A, S, and US which is cited Chamaesyce tamanduana (Boiss.) M. P. by Mueller Argoviensis (1874) as "Regnell Simmons & W. J. Hayden comb. nov. n. 1049, Lund." Our concept of C. setosa is (Figs. 1C, 6G) therefore based on the descriptions published Euphorbia tamanduana Boiss. in Centuria Euphor- by Boissier and Mueller Argoviensis in con- biarum 4. 1860. TYPE: BRAZIL. Bahia: Taman- cert with Pohl 1674, the presumed Riedel s.n. dua, Jacobina, and St. Thorue, Blanchet 3841 collection at C, and Regnell III. 1049. Until (LECTOTYPE (designated here), G; ISOLECTOTYPES, unequivocal syntypes emerge from the fog of BM, F-fragment ex P). history, we feel unable to designate a lecto- Aerial stems several per rootstock, usu- type with confidence. ally annual (sometimes persisting longer), Others have peered into the fog and slender, erect or ascending, relatively reached conclusions at variance from ours. sparsely branched, to 10 cm long, 0.8-1.2 Rambo (1960), in a note on E. selloi, stated: mm diam. at base, densely short-crispate to "I do not know what is meant by E. setosa short-velutinous; stem trichomes uniseriate, (Boiss.) M. Arg., 1.c., and E. chamaerrho- multicellular, white, 0.2-0.7 mm long. dos Boiss.; but we suspect they are all the Leaves either cataphylls or foliage leaves, same as the present species," i.e., E. selloi. strictly opposite; cataphylls small, round- Rambo's study was based on specimens oblong, deciduous; foliage leaves largest at from Rio Grande do Sul and neighboring mid to upper stem; blades ovate-elliptical, Santa Catarina, but C. setosa does not occur 16 x 8 mm, pilose (densely so on abaxial that far south. Following Rambo's lead, A1- surface, less so on adaxial surface): both lem and Irgang (1975) placed E. setosa in surfaces dark green; base somewhat synonymy with E. selloi, citing as evidence oblique; margin entire; apex acute to round- a specimen annotated by Croizat; the spec- ed; petiole 1 mm long; stipules connate, imen in question, however, proves to be C. persistent, broadly triangular, ca. 0.3 mm selloi and not C. setosa. Again, since Allem long, strigose abaxially, tufted straight-hir- 178 BRITTONIA [VOL. 49

TABLE IV COMPARISON OF Chamaesyce tamanduana AND C. viscoides

Character C. tamanduana C. viscoides Stem pubescence Short crispate to short velutinous Long hirsute-velutinous Stem trichomes 0.2-0.7 mm long 1.3-2.3 mm long Leaf base Somewhat oblique Distinctly oblique Leaf color (dry) Dark green Light green to dark brown Appendages Papillate Smooth Appendages Unequal size and shape Unequal size, similar shape Styles 0.7 mm long, short crispate 1 mm long, glabrous (sometimes short hirsute-velutinous) Distribution Central Bahia Goi~is to Minas Gerais

sute adaxially. Cyathia on distal portions of The sheet at G was therefore chosen as the stems, solitary, in dichasial or pseudomon- lectotype because Boissier worked at G and opodial positions; peduncles 1.8-2.6 mm undoubtedly saw this specimen with supe- long; involucre campanulate to somewhat rior diagnostic material. hemispherical, externally short crispate-pu- Chamaesyce tamanduana, known from bescent to short-velutinous, 1 • 1.2 mm at but a single collection, is very similar to mouth; primary lobes 5, keeled, entire, Chamaesyce viscoides; however, the two white-ciliate; glands 4, transversely oblong, species are demonstrably distinct and their drying dark brown, white-ciliate on inner differences are contrasted in Table IV. side; gland bases short crispate-pubescent; These species occur in adjacent states of appendages 1.5 mm long, of unequal Brazil, but the nearest known specimens of widths, planar, perpendicular to rim of cy- C. viscoides were collected about 475 miles athium, glabrous, repand, papillate, white; away from C. tamanduana. Though known wider appendages 2, rounded, 1.6-2.6 mm from but a single collection in 1845, Cha- wide at apex; narrower appendages 2, ob- maesyce tamanduana proves to be a distinct long to weakly obovate, 1-1.4 mm wide at species. This species is very rare; the ab- apex. Staminate flowers about 30. Pistillate sence of collections for over 150 years sug- flower with gynophore crispate-pubescent; gests that it may indeed be extinct. ovary somewhat crispate-velutinous; styles 0.7 mm long, somewhat crispate-pubescent, Chamaesyce viscoides (Boiss.) M. R Sim- connate basally, lower portion erect, bifid mons & W. J. Hayden comb. nov. (Fig. for of length, tips recurved; stigmas cla- 6A) vate. Capsule somewhat crispate-pubescent, Euphorbia viscoides Boiss. in Centuria Euphorbi- 3 mm long, approximately 2.6 mm wide; arum 4. 1860. HOLOTYPE(n.v.): BRAZIL. Camap- trichomes short, uniseriate, multicellular, ua, Riedel s.n. (LE). white. Immature seed subovoid, 1.8 • 1.1 mm, rugose, white. Aerial stems 1-7 per rootstock, apparently Habitat.---Unknown, presumably cerrado. annual, slender, erect, sparsely branched, Distribution.--Brazil, known only from (7)15-25(30) cm long, 0.7-2 mm diam. at Bahia near Jacobina (Fig 15). base, sparsely to densely hirsute-velutinous; Phenology.--Unknown. stem trichomes uniseriate, multicellular, white, occasionally with yellowish deposits at Specimen examined. BRAZIL. Bahia: Tamandu~i, crosswalls, 1.3-2.3 mm long. I~aves either Jacobina, and St. Thorne, Blanchet 3841 (BM, F-frag- cataphylls or foliage leaves, strictly opposite; ment ex R G). cataphylls smaller, round-oblong, deciduous; Boissier (1860) cited the holotype, Blan- foliage leaves largest at mid to upper stem; chet 3841. The sheet from BM consists of blades ovate-elliptical, (15)20-26(33) • 8- but two stems, while that from G has nu- 12(15) mm, sparsely to densely pilose; ad- merous stems and cyathia including the axial surface drying pale green to brown or only known capsule and an immature seed. blackish; abaxial surface somewhat lighter; 1997] SIMMONS & HAYDEN: EUPHORBIACEAE 179

base distinctly oblique; margin entire; apex ernmost ultramafic hill of Tocantine complex, Brooks acute; petiole 1-2 mm long; stipules connate, et al. 312 (MO); San Antonio de Laguna, Brooks et al. 115 (MO); Serra do Caiap6, roadside in cerrado ca. persistent, broadly (sometimes narrowly) tri- 20 km S. of Caiaptnia on rd. to Jataf, Irwin & Sod- angular, 0.3-0.4 mm long, sparsely to densely erstrom 7622 (UB); 9 km from estrada Caiaptnia-Ar- hirsute abaxially, occasionally tufted-hirsute agar~as, Fonseca & Onishi 1042 (UB). Minas Gerais: adaxially. Cyathia on distal and sometimes Municfpio Campina Verde, Botafogo, Macedo 626 (S). basal to middle portions of stems; solitary, in Chamaesyee viscoides is a poorly col- dichasial or pseudomonopodial positions; pe- lected species known primarly from the duncles 2-5(13) nun long; involucre campan- province of Goi~is, Brazil. The above de- ulate or sometimes hemispherical, externally scription differs from that by Boissier and short hirsute-velutinous, 1.3-1.6(2.1) • 1.6- Mueller Argoviensis in which the cyathial 2(2.6) mm at mouth; primary lobes 5, keeled, involucres are described as campanulate; entire, white ciliate; glands 4, transversely ob- the available material shows they may also long, drying light to dark brown to green, be distinctly hemispherical, e.g., Macedo densely white ciliate on inner side; gland bas- 626. Also the leaves do not neccesarily dry es short hirsute-velutinous; appendages obo- blackish but also pale green to gray or light vate-rounded, unequal (to somewhat larger), to dark brown. An anomaly is evident in 1-2.5 mm long, planar, perpendicular to rim Irwin & Soderstrom 7622, in which a single of cyathium, glabrous, repand to erose, white stem bears a ternate node, reminiscent of (sometimes pink). Staminate flowers ca. 30. Chamaesyce potentilloides. Pistillate flower with gynophore 2.3 nun long at matttrity, short hirsute-velutinous; ovary Acknowledgments pubescence short, uniseriate, multicellular We wish to thank the curators and staff of white hirsute-velutinous; styles 1 mm long, the following herbaria for providing loans or glabrous to sparsely short hirsute-velutinous, photographs of specimens: A, B, BA, BAF,, connate basally, lower portion erect, bifid for BM, BR, C, CTES, DAV, E, E FI, G, GB, of length, tips recurved; stigmas clavate. GH, HAS, ICN, JE, JEPS, K, L, LD, LIL, Capsule hirsute-velutinous, 2.7-3.3 mm • 3- LE M, MICH, MO, MU, MVFA, NY, RB, 3.3 mm wide; trichomes short, uniseriate, RSA, S, SI, SP, U, UB, UC, US, W, WIS, multicellular, white. Seed subovoid, Z tetrag- WU. Grady L. Webster generously provided onal, 1.8 • 1.1 mm, rugose-punctate, brown; fluid-preserved specimens of C. potentillo- base truncate. ides, and Antonio C. Allem and Michael J. Habitat.--Cerrado, especially over ser- Huft shared useful information in early stages pentine and mafic substrates. of this work. We thank Kevin C. Nixon and Distribution.--Brazil, from central and Lawrence M. Kelley for providing construc- southern Goi~is to western Minas Gerais tive criticism of the phylogenetic section. (Fig. 15). Betty Tobias was indispensible in obtaining Phenology.--Flowering and fruiting interlibrary loans for our use. Geoffrey Levin, year-round. Grady Webster, and an anonymous reviewer Specimens examined. BRAZIL. Without specific made a number of constructive suggestions locality: St.-Hilaire 780 (A-fragment ex P, mixed col- for improvement of the text. Financial sup- lection with C. nana); Pouco du Ribeirao, Glaziou port was provided by the University of Rich- 22079 (A-fragment ex P, G-mixed collection). Distri- mond Undergraduate Research Committee to Fererah Brasilia e Niquelandia, Pires et al. 9670 (DAV). Goi~is: Burchell 7205 (BR, K), Weddell 2623 and the D. A. Kuyk endowed chair research (A-fragment ex P); Barro Alto, 11-12 km from town fund. on rd. running SW through area of serpentinized pe- ridotite, Brooks & Reeves 677 (K); Cana Brava, area Literature Cited between two chrysolite mines, Brooks et al. 445 (K); Cavalcante, Burchell 7660 (BR, K); Gammeleira, Pohl Adams, E. N. 1972. Consensus techniques and the 2179 (W); Gaueuelevia, Pohl & Burchell s.n. (G); 35 comparison of taxonomic terms. Syst. Zool. 21: km (by rd.) N of Goianesia, Brooks et al. 122 (MO); 390-397. Macedo, ca. 15 km N of Niquelandia, Brooks et al. Allem, A. C. 1977. Notas sistem~iticas y nuevos si- 193 (MO); Municipio Rio Verde, Cad. Alta, Faz. Eu- n6nimos en Euphorbiaceae de Amtrica del Sur-- gauo. Macedo 2663 (MO, S, US); Niquelandia, south- V. Revista Brasil. Biol. 37: 223-231. 180 BRITTONIA [VOL. 49

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