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A NEW SPECIES OF JATROPHA (EUPHORBIACEAE) FROM NICARAGUA' GRADYL. WEBSTER2 ABSTRAcr A new species,Jatrophastevensii,is describedfromcollectionsin Dept. Boaco in Nicaragua. It may be assigned to subg. Curcas and appears relatedto Jatrophafremontioides,a species fromsouthern Mexico. Jatrophastevensiirepresentsyet anotherextensionof the Mexican xerophyticelementinto CentralAmerica, and the second recordforJatrophasubg. Curcas. When JatrophacostaricensisWebster & Poveda was describedfromGuanacaste,Costa Rica, some yearsago (Webster& Poveda, 1978), itwas predicted that other xeric relict taxa mightbe discoveredelsewherein CentralAmerica.Recent botanical explorationin Nicaragua has disclosed not only a numberof new populations of Jatropha podagrica Hook. in rockyareas in Dept. Esteli,but also on basaltic ridgesin Dept. Boaco a species that appears to be undescribed.Unlike J. podagrica, which belongs to subg. Jatropha (Dehgan & Webster,1979), theplantfromBoaco clearlyis referableto subg. Curcas. beneath midriband secondariesraised, veinlets prominent;marginsentire,eglandular.Monoecious; dichasia terminal,oftenpaired, with peduncle 1-2.5 cm long, branches hispidulous; bracts oblong-lanceolate to oblanceolate, glabrous or tomentulose,lower ones 4-5 mm long and 1.2-1.3 mm broad; pistillateflowers0-2 per dichasium,at lowernodes; staminateflowers1015,at upperdichotomies.Staminateflower:pedicel 0.5-0.8 mm long,articulatedat base; sepals 5, lanceolate,obtuseor subacute,entire,glabrous or hirsutulous,2.5-4.8 mm long, 1.2-2 mm broad; petals 5, pale green, oblong, glabrous abaxially,copiouslyhirsutulousadaxiallyin lowJatrophastevensiiWebster,sp. nov. TYPE: Nic- er half,5.5-6 mm long, coherentinto a tube in aragua, Dept. Boaco, 1.6 km SW of Santa lower 1/3,midribwith several sharplyascending Cruz, low ridgeofbasaltic lava, 140-160 m, lateralsthatdichotomizedistally;disk glands 5, 12024'N, 85050'W, 7 June 1984, W. D. Ste- cubical, glabrous,0.5-0.6 mm high;stamens 10, vens 22902 (MO, holotype;DAV, isotype; biverticellate,monadelphous below into a slenadditional isotypes to be distributed). It der column 3-4 mm high,outerstamenson filshould be noted thatthe typecollectionin- aments ca. 1 mm long. Pistillateflower:pedicel cludes both glabrous and pubescent speci- glabrousor tomentulose,becoming3-1 1 mm long mensand was apparentlygatheredfromsev- in fruit;sepals 5, ellipticor lanceolate,obtuse or eral individuals. subacute, becoming in fruit5.5-6.5 mm long, 2.5-3.8 mm broad; petals 5, ovate at base taAbJ.olivaceadiffert dichasiomenor, minorestipulis obsoletis,fohiis nonglanduligeris;peringto oblong obtuse tips,pale green,ca. 5.8integris marginibus ab J.alamaniifoliiselobatis,sepalisminoribus, petalis 6 mm long,4-4.2 mm broad, hirsutulousadaxtantum1/3longitudinis coalitis;ab J.fremontioide foihis ially,coherentin lower 1/3;disk dissected into 5 dichasiononcapituliforme. acuminatis, lobes; ovary smooth,glabrous,sharplycarinate, Deciduous shrub to 3 m high; twigs terete, 3-locular;stylesca. 3 mm long,connatein lower greyish-or reddish-brown,glabrous or hispidu- 1/3,erect,scarcelybifid;stigmasdilated, elliptic, lous, exudingcloudy latex when cut. Leaves al- 0.7 mm long, 0.3 mm broad. Capsule smooth, ternateor clusteredon spur shoots; stipulesob- 3-lobed,prominently3-carinateon back ofcocci, solete; petioles slender, 5-25 mm long; blades 1.5-1.6 mm in diameter;seeds ellipsoidal, ca. 9 thinlychartaceous,ovate contractedto an acu- mm long,smooth;carunclebrownish,deeplyflaminatetip,cordateat base, loosely tomentoseto bellatelylobed, 2.5 mm long, 4 mm broad. glabrous beneath, 2-4 cm long, 1-3 cm broad, Additionalcollectionsexamined. NICARAGUA. palmately 5-veined at base, brochidodromous, BOACO:1 kmE of Santa Cruz, 200 m, Moreno22467B I 2 I wish to thankMs. Lynn Gillespie forthe photographof the typecollection. Departmentof Botany,Universityof California,Davis, California95616. ANN. MISSOURI BOT. GARD. 74: 117-120. 1987. This content downloaded from 169.237.8.35 on Mon, 16 Sep 2013 18:55:49 PM All use subject to JSTOR Terms and Conditions 118 1mmI ANNALS OF THE MISSOURI BOTANICAL GARDEN s $ K f [VOL. 74 f X ABC icm{ D E F FIGURE 1. Flowers and leaf of Jatrophastevensii(Stevens22902). -A-C. Staminateflower.-A. Sepal. -B. Petal. -C. Androeciumand disk-segment. -D-F. Pistillateflower.-D. Sepal. -E. Petal.-F. Gynoecium.-G. Leaf. (MO). Matagalpa: San Juanillo,8 km SE of Ciudad Dario, 500 m, Grijalva2599 (DAV, MO). Jatrophastevensii,named in honor of Warren Douglas Stevens,the leading studentand collectoroftheNicaraguanflora,belongsto subg. Curcas (Adans.) Griseb. by virtueof its flowerswith entireimbricatesepals, coherentpetals,and androeciumof 10 monadelphousstamens(Dehgan & Webster,1979). Withinsubg. Curcas, it is referableto sect. PlatyphyllaeDehgan & Webster because of its 3-locularcarinatefruitsand biseriateanthers.However,it is divergentfrommost species of sect. Platyphyllaein havingelongated seeds with a prominentcaruncle. As noted by McVaugh (1945), J.fremontioidesStandl. from Oaxaca differs fromotherspecies ofsubg. Curcas in its prominentlycarunculate seeds. Furthermore, Dehgan (1980) has indicated that J. fremontioidesis distinguishedby anisocytic stomata, a featureunique in the genus. The prominentlycarunculate seeds, monoecious flowerproduction,and small entirecordate leaves linkJ. stevensiiwithJ.fremontioidesand indicate that the latteris the closest relative of thenew species. The two speciesforma subgroup of sect. Platyphyllaediffering frommore typical species such as J. platyphylla,J. alamanii, and J. ciliata, which have largermore-or-lesslobed leaves, flowersproduced dioeciously,and seeds with small caruncles. Nevertheless,the staminate and pistillateflowersof such species as J. ciliata are quite similar overall to those of J. stevensiiand J. fremontioides,and the preponderance of evidence does not seem to compel of sect. any modificationsin thecircumscription Platyphyllaeat this time. The discoveryofJ.stevensiiin Nicaraguabrings to threethe number of endemic Central American species of Jatropha: J. podagrica Hook. (eastern Guatemala to Nicaragua), J. stevensii This content downloaded from 169.237.8.35 on Mon, 16 Sep 2013 18:55:49 PM All use subject to JSTOR Terms and Conditions 1987] FiGURE2. WEBSTER-JATROPHA Photographof type collection of Jatrophastevensii(Stevens 22902), left-handglabrous branchwithpistillate pubescent flowers. flowers; withcapsuleand staminate right-hand (Nicaragua), and J. costaricensisWebster& Poveda (Guanacaste, Costa Rica). These speciesbesubgeneraand sections,J. long to two different podagnca in subg.Jatrophasect. Peltatae and J. stevensiiand J. costaricensisin subg. Curcas sect 119 asnch However, as notedby Websterand Platyphyllae. Poveda (1978), J. costaricensisis most closely related to J. alamanii Muell. Arg. of southern notto J.stevensii. Mexico (Oaxaca) and therefore The CentralAmericanspecies ofJatropha ap- This content downloaded from 169.237.8.35 on Mon, 16 Sep 2013 18:55:49 PM All use subject to JSTOR Terms and Conditions 120 ANNALS OF THE MISSOURI BOTANICAL GARDEN [VOL. 74 pear to representa depauperateextensionof the vasion of plants ancestralto J. podagrica must largeassemblage of endemic species in southern be more recent,and indeed perhaps subsequent Mexico, as remarkedby Webster and Poveda to the closing of the Panamanian gap. thatthefloristicbreakfor (1978). It is interesting LITERATURE CITED Jatrophacomes not at the Isthmus of Tehuantepecbut in Guatemala; however,thereis clearly DEHGAN, B. 1980. Application of epidermal morphologyto taxonomic delimitationsin the genus a decline in diversityeast of the Isthmus. JatrophaL. (Euphorbiaceae). Bot. J.Linn. Soc. 80: In contrastto studies such as that of Savage 257-278. (1982) on vertebratedistributionsin Mesoamer1979. Morphology and & G. L. WEBSTER. ica, thereis clearlyno ancientCentralAmerican infragenericrelationshipsof the genus Jatropha (Euphorbiaceae). Univ. Calif. Publ. Bot. 74: 1-73. centerforxericEuphorbiaceae such as Cnidoscolus, Jatropha,and Manihot. Instead, in Meso- GENTRY, A. J. 1982. Neotropical floristicdiversity: phytogeographicalconnections between Central americanJatrophatherehas been an invasion of and South America, Pleistocene climatic fluctuaone species of subg. Jatrophafromthe south (J. tions,or an accidentofthe Andean orogeny?Ann. podagrica) and two species of subg. Curcas from Missouri Bot. Gard. 69: 557-593. the north(J. costaricensisand J. stevensii).Gen- MCVAUGH, R. 1945. The genusJatrophain America: principal intragenericgroups. Bull. Torrey Bot. try( 1982) considersthatxericMesoamericantaxa Club 72: 271-294. are ultimatelyof southernorigin.However, for SAVAGE, J.M. 1982. The enigmaoftheCentralAmerJatropha subg. Curcas and other distinctive ican herpetofauna:dispersalsor vicariance?Ann. Missouri Bot. Gard. 69: 464-547. Mexican xerophytetaxa such as the Fouquieriaceae, this migrationfromthe south must have WEBSTER, G. L. & L. J. POVEDA. 1978. A phytogeographicallysignificantnew species of Jatropha been so ancientthatthese taxa may be regarded (Euphorbiaceae) from Costa Rica. Brittonia 30: as autochthonousto Mexico in terms of their 265-270. evolutionarydiversification.In contrast,the in- This content downloaded from 169.237.8.35 on Mon, 16 Sep 2013 18:55:49 PM All use subject to JSTOR Terms and Conditions