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Home , Euphorbiaceae, Jatropha, Manihot

A NEW OF () FROM NICARAGUA'

GRADY L. WEBSTER2

ABSTRAcr A new species,Jatropha stevensii, is describedfrom collections in Dept. Boaco in Nicaragua. It may be assigned to subg. Curcas and appears related to Jatrophafremontioides, a species fromsouthern Mexico. Jatrophastevensii represents yet another extensionof the Mexican xerophyticelement into CentralAmerica, and the second recordfor Jatropha subg. Curcas.

When Jatropha costaricensisWebster & Po- beneath midrib and secondaries raised, veinlets veda was describedfrom Guanacaste, Costa Rica, prominent;margins entire, eglandular. Monoe- some yearsago (Webster& Poveda, 1978), it was cious; dichasia terminal,often paired, with pe- predicted that other xeric relict taxa might be duncle 1-2.5 cm long, branches hispidulous; discoveredelsewhere in CentralAmerica. Recent oblong-lanceolate to oblanceolate, gla- botanical explorationin Nicaragua has disclosed brous or tomentulose,lower ones 4-5 mm long not only a numberof new populations of Jatro- and 1.2-1.3 mm broad; pistillateflowers 0-2 per pha podagrica Hook. in rockyareas in Dept. Es- dichasium,at lowernodes; staminateflowers 10- teli, but also on basaltic ridgesin Dept. Boaco a 15, at upperdichotomies. Staminate : ped- species that appears to be undescribed. Unlike icel 0.5-0.8 mm long,articulated at base; sepals J. podagrica, which belongs to subg. Jatropha 5, lanceolate,obtuse or subacute,entire, glabrous (Dehgan & Webster,1979), theplant from Boaco or hirsutulous, 2.5-4.8 mm long, 1.2-2 mm clearlyis referableto subg. Curcas. broad; petals 5, pale green, oblong, glabrous abaxially,copiously hirsutulous adaxially in low- Jatrophastevensii Webster, 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,midrib with several sharplyascending Cruz, low ridgeof basaltic lava, 140-160 m, lateralsthat dichotomize distally;disk glands 5, 12024'N, 85050'W, 7 June 1984, W. D. Ste- cubical, glabrous,0.5-0.6 mm high; 10, vens 22902 (MO, holotype; DAV, isotype; biverticellate,monadelphous below into a slen- additional isotypes to be distributed). It der column 3-4 mm high,outer stamens on fil- should be noted thatthe typecollection in- aments ca. 1 mm long. Pistillateflower: pedicel cludes both glabrous and pubescent speci- glabrousor tomentulose,becoming 3-1 1 mm long mens and was apparentlygathered from sev- in ;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 ta- AbJ. olivacea differt dichasio menor, minore stipulis obsoletis,fohiis integris marginibus non glanduligeris; peringto oblong obtuse tips,pale green,ca. 5.8- ab J.alamanii foliis elobatis, sepalis minoribus, petalis 6 mm long, 4-4.2 mm broad, hirsutulousadax- tantum1/3 longitudinis coalitis; ab J.fremontioide foihis ially, coherentin lower 1/3;disk dissected into 5 acuminatis,dichasio non capituliforme. lobes; smooth,glabrous, sharply carinate, Deciduous to 3 m high; twigs terete, 3-locular; stylesca. 3 mm long,connate in lower greyish-or reddish-brown,glabrous or hispidu- 1/3,erect, scarcely bifid; stigmas dilated, elliptic, lous, exuding cloudy when cut. al- 0.7 mm long, 0.3 mm broad. Capsule smooth, ternateor clusteredon spur shoots; stipulesob- 3-lobed,prominently 3-carinate on back ofcocci, solete; petioles slender, 5-25 mm long; blades 1.5-1.6 mm in diameter; ellipsoidal, ca. 9 thinlychartaceous, ovate contractedto an acu- mm long,smooth; caruncle brownish, deeply fla- minatetip, cordate at base, loosely tomentoseto bellatelylobed, 2.5 mm long, 4 mm broad. glabrous beneath, 2-4 cm long, 1-3 cm broad, Additionalcollections examined. NICARAGUA. palmately 5-veined at base, brochidodromous, BOACO:1 kmE of Santa Cruz, 200 m, Moreno22467B

I I wish to thank Ms. Lynn Gillespie forthe photographof the typecollection. 2 Departmentof Botany,University of California,Davis, California95616. ANN. MISSOURI BOT. GARD. 74: 117-120. 1987.

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D E F FIGURE 1. and of Jatrophastevensii (Stevens 22902). -A-C. Staminate flower.-A. Sepal. -B. Petal. -C. Androeciumand disk-segment.-D-F. Pistillateflower. -D. Sepal. -E. Petal.-F. .-G. Leaf.

(MO). Matagalpa: San Juanillo, 8 km SE of Ciudad The prominentlycarunculate seeds, monoe- Dario, 500 m, Grijalva2599 (DAV, MO). cious flowerproduction, and small entirecordate Jatrophastevensii, named in honor of Warren leaves link J. stevensiiwith J. fremontioides and Douglas Stevens,the leading studentand collec- indicate that the latteris the closest relative of torof theNicaraguan flora,belongs to subg. Cur- thenew species. The two species forma subgroup cas (Adans.) Griseb. by virtueof its flowerswith of sect. Platyphyllaediffering from more typical entireimbricate sepals, coherentpetals, and an- species such as J. platyphylla,J. alamanii, and droeciumof 10 monadelphousstamens (Dehgan J. ciliata, which have largermore-or-less lobed & Webster,1979). Withinsubg. Curcas, it is re- leaves, flowersproduced dioeciously,and seeds ferableto sect. PlatyphyllaeDehgan & Webster with small caruncles. Nevertheless,the stami- because of its 3-locular carinatefruits and bise- nate and pistillateflowers of such species as J. riateanthers. However, it is divergentfrom most ciliata are quite similar overall to those of J. species of sect. Platyphyllaein having elongated stevensiiand J. fremontioides,and the prepon- seeds with a prominentcaruncle. As noted by derance of evidence does not seem to compel McVaugh (1945), J. fremontioidesStandl. from any modificationsin the circumscriptionof sect. differsfrom other species of subg. Curcas Platyphyllaeat this time. in its prominentlycarunculate seeds. Further- The discoveryof J. stevensii in Nicaraguabrings more, Dehgan (1980) has indicated that J. fre- to threethe number of endemic Central Amer- montioides is distinguishedby anisocytic sto- ican species of Jatropha: J. podagrica Hook. mata, a featureunique in the . (eastern Guatemala to Nicaragua), J. stevensii

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FiGURE2. Photographof type collection of Jatrophastevensii (Stevens 22902), left-handglabrous asnch withcapsule and staminateflowers; right-hand pubescent branch with pistillate flowers.

(Nicaragua), and J. costaricensisWebster & Po- Platyphyllae.However, as noted by Websterand veda (Guanacaste, Costa Rica). These species be- Poveda (1978), J. costaricensisis most closely long to two differentsubgenera and sections,J. related to J. alamanii Muell. Arg. of southern podagnca in subg. Jatrophasect. Peltatae and J. Mexico (Oaxaca) and thereforenot to J.stevensii. stevensiiand J. costaricensisin subg. Curcas sect The CentralAmerican species of Jatrophaap-

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 depauperateextension of the vasion of ancestral to J. podagrica must largeassemblage of endemic species in southern be more recent,and indeed perhaps subsequent Mexico, as remarked by Webster and Poveda to the closing of the Panamanian gap. (1978). It is interestingthat the floristicbreak for Jatrophacomes not at the Isthmus of Tehuan- LITERATURE CITED tepec but in Guatemala; however,there is clearly DEHGAN, B. 1980. Application of epidermal mor- a decline in diversityeast of the Isthmus. phologyto taxonomic delimitationsin the genus In contrastto studies such as that of Savage JatrophaL. (Euphorbiaceae). Bot. J.Linn. Soc. 80: 257-278. (1982) on vertebratedistributions in Mesoamer- & G. L. WEBSTER. 1979. Morphology and ica, thereis clearlyno ancientCentral American infragenericrelationships of the genus Jatropha centerfor xeric Euphorbiaceae such as Cnidosco- (Euphorbiaceae). Univ. Calif. Publ. Bot. 74: 1-73. lus, Jatropha,and . Instead, in Meso- GENTRY, A. J. 1982. Neotropical floristicdiversity: between Central americanJatropha there has been an invasion of phytogeographicalconnections and South America, Pleistocene climatic fluctua- one species of subg. Jatrophafrom the south (J. tions,or an accidentof the 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 genusJatropha in America: try( 1982) considersthat xeric Mesoamerican taxa principal intragenericgroups. Bull. Torrey Bot. Club 72: 271-294. are ultimatelyof southernorigin. However, for SAVAGE, J.M. 1982. The enigmaofthe Central Amer- Jatropha subg. Curcas and other distinctive ican herpetofauna:dispersals or vicariance?Ann. Mexican xerophytetaxa such as the Fouquieri- Missouri Bot. Gard. 69: 464-547. aceae, this migrationfrom the south must have WEBSTER, G. L. & L. J. POVEDA. 1978. A phytogeo- species of Jatropha been so ancientthat these taxa may be regarded graphically significantnew (Euphorbiaceae) from Costa Rica. Brittonia 30: as autochthonous to Mexico in terms of their 265-270. evolutionarydiversification. In contrast,the in-

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