NUMBER 7 WILLIAMS: CAPRARIA (SCROPHULARIACEAE) 53 A REVISION OF CAPRARIA ( SCROPHULARIACEAE) Justin K. Williams Department of Biological Sciences, Sam Houston State University, Huntsville, Texas 77341-2116 Abstract: Herbarium and field studies of the chiefly neotropical genus Capraria have led to the recognition of four species. Capraria frutescens and C. mexicana are es­ sentially endemic to Mexico. Capraria biflora is a widespread species that occurs throughout Mexico, Central and South America, the West Indies, and southern Flor­ ida. Capraria peruviana grows in northwestern South America and the Galapagos Islands. A complete account of synonymy and typification is provided, along with a key to species, scanning electron micrographs of pollen, stigmas and seeds, photo­ graphs, illustrations, and distribution maps. Keywords: Capraria, Caprarieae, Gratioleae, Leucophylleae, Myoporaceae, Scrophu­ lariaceae, SEM. Capraria L. (Latin = goat, in reference (2001) six species. In this work four species to observations that goats consume the of Capraria are recognized; full synonymy, leaves (Sprague (1921)) is a neotropical ge­ illustrations and detailed exsiccate are pre­ nus of suffruticose herbs and subshrubs dis­ sented for all species. tributed from southern Florida to central South America. Capraria is unique within GENERIC RELATIONSHIPS the Scrophulariaceae in having alternate leaves with external punctate glands and Throughout its history, the placement oil-secreting cavities. The relationship of of Capraria has been under dispute (Table Capraria within the Scrophulariaceae has 1). Bentham (1846) placed it in subfamily been under considerable dispute (see Ge­ (his suborder) Rhinanthoideae (with pos­ neric Relations). The species, however, are terior corolla lobes interior in bud), tribe easily delineated morphologically. Sibthorpeae (with alternate leaves, and Linnaeus (1753) established the genus flowers solitary in the leaf axils), along with with the description of Capraria biflora L. Sibthorpia L., Hornemannia Benth., Hemi­ Subsequently, 49 names were proposed in phragma Wall., Camptoloma Benth. and Capraria. Most of these were transferred or Scoparia. synonymized under other genera (e.g., An­ Bentham (1876) later reduced the tribe ticharis Endl., Freylinia Colla, Scoparia L., Sibthorpeae to subtribe Sibthorpieae of and Stemodia L.). Sprague (1921), in his subfamily (his series) Rhinanthoideae, tribe treatment of Capraria, provided a list of ex­ Digitaleae with Hornemannia reduced to a cluded species that is included and expand­ synonym of Sibthorpia, and Camptoloma ed at the end of the present article. repositioned in his subtribe Digitalieae. A treatment of Capraria is pertinent at Bentham's Digitaleae was later viewed as a this time, considering the numerous mis­ heterogenous group with no clear definition identifications of specimens in various her­ by Thieret (1967). baria observed by the present author and Wettstein (1891) essentially followed the discrepancy in the number of species Bentham's (1876) treatment, differing only recognized by various botanists: Lersten in the non-recognition of subtribes for tribe and Curtis (2001) considered Capraria to Digitaleae. be monotypic, Mabberley (1987) recog­ Sprague (1921) retained Capraria in the nized four species, Sprague (1921) five spe­ tribe Digitaleae, emphasizing that Scoparia cies, and Mendez Larios and Villasenor Rios was its closest relative because both pos- LUNDELLIA 7:53-78. 2004 54 LUNDELLIA DECEMBER, 2004 TABLE 1. Familial, subfamilial, and tribal placement of Capraria by various authors. Author Family Subfamily Tribe Bentham (1846) Scrophulariaceae Rhinanthoideae Sibthorpeae Bentham (1876) Scrophulariaceae Rhinanthoideae Digitaleae Wettstein (1891) Scrophulariaceae Rhinanthoideae Digitaleae Sprague (1921) Scrophulariaceae Rhinanthoideae Digitaleae Thieret (1954) Scrophulariaceae Rhinanthoideae Digitaleae Thieret (1967) Scrophulariaceae Antirrhinoideae Gratioleae Niezgoda & Tomb (1975) Myoporaceae Leucophylleae Barringer (1993) Scrophulariaceae Caprarieae Mendez Larios and Villasenor Rios (2001) Scrophulariaceae Antirrhinoideae Digitaleae Olmstead (2004) Scrophulariaceae Leucophylleae sessed leaves with punctate glands along the that the pollen of Capraria is spherical and upper leaf surface. Sprague also noted that 3-colpate, as opposed to 4-colpate pollen Hemiphragma "has relatively little in com­ found in most Scrophulariaceae. They also mon with either" Capraria or Scoparia, sug­ found 3-colpate pollen in Leucophyllum gesting that its placement near them was Bonpl., Eremogeton Standl. & L. 0. Wil­ artificial, based largely upon a shared po~­ liams (tribe Leucophylleae), and some My­ session of alternate leaves. oporaceae. Due to the similarity in pollen Thieret (1954) initially followed the structure, Niezgoda and Tomb suggested treatments of Bentham (1876) and Wett­ the placement of Capraria close to the Leu­ stein (1891), but later transferred both Ca­ cophylleae, which they favored placing as a praria and Scoparia into the subfamily An­ subfamily of the Myoporaceae. Argue tirrhinoideae, tribe Gratioleae (Thieret, (1980), however, observed 3-colpate pollen 1967). This was based, in part, on the ob­ in Mimulus L. (sections Mimulus and Ery­ servations of Pennell (1920, 1935), who thranthe), Penstemon Schmidel (tribe Che­ noted that the posterior corolla lobes are loneae), Celsia L. (tribe Verbasceae), and se­ external in bud in both taxa, and that they lected genera of tribe Gratioleae (Lancea possess glandular hairs similar to other Gra­ Hook. f. & Thomson, Artanema D. Don, tioleae. Thieret also suggested that the sca­ and Conobea). Indeed his work vitiates the lariform-reticulate seeds (his "Bacopa" dramatic placement of Capraria in the My­ type) of Capraria and Scoparia are charac­ oporaceae, suggesting instead its retention teristic of many Gratioleae, and that their in the Scrophulariaceae tribe Gratioleae small 4-valved capsules are similar to those near Conobea, as proposed by Thieret found in the genus Conobea Aubl., a native (1967). of tropical America with opposite leaves Henrickson and Flyr (1985) discussed and punctate glands. in detail the systematic position of Eremo­ Arekal et al. (1971) related Capraria bi­ geton and Leucophyllum, concluding that flora to Scoparia dulcis L. on the basis of both genera were more closely related to embryological data. This was later negated members of the traditional Scrophulari­ by Hakki (1975), who noted "no secondary aceae and not to the Myoporaceae. How­ haustoria developed in C. biflora as has ever, they did not study Capraria, nor sug­ been reported by Arekal et al. (1975) for gest it as a possible relative. Scoparia dulcis-the closest relative of our Barringer (1993) did not recognize sub­ genus." families for the Scrophulariaceae and placed Niezgoda and Tomb (1975) showed Capraria in his newly described monotypic NUMBER 7 WILLIAMS: CAPRARIA (SCROPHULARIACEAE) 55 TABLE 2. Morphological variation among the four species of Capraria. Capraria peruviana Capraria mexicana Capraria biflora Capraria frutescens Vestiture none none pilose with few glan- pilose and glandular dular hairs (occa- sionally glabrous) Stems ramified ramified ramified monopodial Leaf blades lanceolate lanceolate spatulate-lanceolate spatulate Pedicel length 5-25 mm 5-25 mm 5-25 mm 1-4 mm Sepal shape lanceolate lanceolate lanceolate oblong Corolla symmetry radial radial bilateral bilateral Corrolla tube length 0.8-1.5 mm 2-3 mm 4-6mm 4-7 mm Corrolla lobes pu- bescent no no yes yes Corolla color white light green-white white with purple white with purple blotches on lower blotches on lower surface surface Stamen number 5 5 4-5 4 Stamen arragement radial radial bilateral bilateral Stamens exserted yes yes ±yes no Style length 0.75-1.5 mm 3-5 mm 3-5 mm 3-5 mm Style exserted past corolla tube no yes ±yes no Style pubescent no no no/yes no Stigma shape linear linear linear reniform tribe Caprarieae, suggesting no close rela­ acters with various members of the tribes tives for it. Gratioleae and Leucophylleae. Lersten and Curtis (2001) noted that Capraria and Leucophyllum are the only MORPHOLOGY genera of Scrophulariaceae with true secre­ tory oil cavities but noted that these two METHODS: The morphological study is genera differ in the number and arragement based on field observations by the author in of these cavities (see Morphology section). Mexico and the examination of approxi­ They did not propose a systematic place­ mately 1600 herbarium specimens. Speci­ ment of Capraria; instead, they cited Ra­ mens were examined at or borrowed from man (1991) who, based on a study of tri­ the following institutions: BM (2 types), F chomes in the Scophulariaceae, proposed (330 specimens), FLAS (40), K (3 types), no "taxonomic conclusion" for Capraria. MA (1 type), MO (274), NY (445), P (2 Recently, Olmstead (2004) placed Ca­ types), TEX-LL (96), US (354). There are at praria in the tribe Leucophylleae with Ere­ least 16 morphological characters (Table 2) mogeton and Leucophyllum. that serve to distinguish Capraria from oth­ The systematic position of Capraria er genera and/or the four species from one within the Scrophulariaceae appears unre­ another as noted below. solved. I am inclined to recognize Capraria For Scanning Electron Microscopy in the monotypic Caprarieae as suggested (SEM) studies, the following procedures by Barringer (1993). Nevertheless, I ac­ were followed. Pollen, stigma and seeds of knowledge that Capraria shares many