A New Shrub Species from a Dry Forest of Puerto Rico,
Reynosia vivesiana (Rhamnaceae)
J. Carlos Trejo-Torres
(Cincldaanos dlel Karso, 497 l Emiliano Pol (Box 230), IUrl . Ia C(imlre, San Juan. IPerto Rico
00926-5636. Cuirrenti ahddress: SelvaKarst: (oitipaiafa dle Invesligacion para las Selvas Karslicas,
Calle 53-1) # 258 x 44 y 46, F'racc. Francisco dle Monteojo, MWriida, Yucatan 97203, Mexico.
karsensis@ vahoo.com. mx
AHsri.\(:r. Reynosia riresidani Trejo (lhalnraceae) is
a previously tunrecoguized species of woody shrub. It
is known froii a d1ry forest in southweslern Puerto(
icoli. \wherel i has been recoirdled only in a small larea
in the (;llanica Forest IReserve. lThe plll il was trealed
for mIore thain seven decades as R. ,guaina Urblan, a
related species froni the Virgin Islands. The new R.
v'ir'siiona is separalted fron R. guinat and the other
two speclies of Ret osia Griselach from IilPuerto lieo
)y its glal1rons twigs. petioles. and slipels. andI iv its
sialler ruiils (ca. ) iun long), aimo olliher eatuires.
Thie seregatlion of AR. viresianl froni R. gudma
heightlens the importance of both species from a
coniservalion slandpoinlt. Rased on IU(CN l'e isl
criteria, R. irrcie ria can ill e <ld fi led as (iCitically
Enlaniglered ((C; ) and cotiiseiienilly needs legal
protecl ion.
Rltstl Mw. Rei'cnosia rirc'siani Tr'jo (lRhliainaeeae) es
una especie die arihusto leioso previanetlle no
catalogada. Es conoeida en el )os(Iln sei o del
suriesle de IPuerto Iiio, londle ha sido registrada eni
ni afira peiilliena ( la Ileserva Forestal de (u.nl ica.
La planla fue traltada p)or mniis de sicte decadas coneo
R. gani(i Uirban, una especie Iherana de las Islas
\irgenes. La niieva R. riresiana se distingue de R.
,guamrn V de l as otrls dos esp)ecies de ReIynrosia
Grisetbach Ic l Puerto Rico por sls lruml s jivenes,
lec(iolos y eslipelas glahlras, asi (lle tono or sils Irltos
tias pelllenos dle alredeldor de 9 nini de largo, entr
otlrs caraelerfsticas. L,a segreglacin de R. riresi(na
resp)ecto de R. gunmn realza la iniporlaineia dle aintias
eslpeeies deslde el pnto lie visia de st conservaci(n.
(Con base en los eriterios de la Iisla l{oja ide la I C(;N
R. riresian pnetlde delfinirse ('o1no en peligro cr'lieco v
consecimente<elle anlerila prolecion legal.
Key ordnts: Antilles, IUCN ied I,ist. IPuerlo icoii,
Rey'nosia, lliaininacae.
ReI'.osia ri'cesiana Trejo (Rlhainnaweae) is a
previously unrecognizedl species of shrubl) known onlyv
fromii a lry forest in sotihwvestern Puerto Rico. froun
1932-19(). it wags collected at least 13 tlimes in a
smallr area itn tie Gina Iica Forest Reserve andl
identified as R. gaiai Utirbant. a species roim the
Virgin Islands. In facl. thie ( 1awiing of R. g a.nl in lle
book 7Tre.es of 'Pue'rto Rico and the Iirgin .sl7nd.A (Little
et al.. 1974) might actually Ie the new R. rircesiana.
Unfortilalelv. the lack of a; herbarium vouchwer
refereince on tllihe drawing preventis the confirrnation
of this statement.
\r llile stu(lying rare p1lan1 s of thl region in sCeveral
herbaria (RM. C. (;1(:) . (:CIQH. F. F (;. (; H. (;()ET,
.IBSI), K, I., MAPR, N'Y, P. S.1, UPH, UPl RP, US. \V), I
reailized tlat specimeis from Puerto Hicco pIrevioulsly
Virgin Islands. To study lhe live plants. I visited wild
plopulations in (Giianica (Puerto Rico). St. John (U.S.
Virgin Islands), and Virgin G(orda (tBritish Virgin
distinguishabl)e by their lplaniil archiltecture, bark.
leaves, pubescence, fruits, seeds, and seellings. The
several elongaled slets borne al thle veryv base of the
tree, arranged in a diffuse, obeonic crown, while /.
gticanst, is a siiall Iree or shrub illith a ordinary dense
crown. Thlle bark of R. riesieian is smolloth and glacous
gray. while that of R. gruai( is vertically furrowed and
1brownish 7gray. 1The leaves of R. liv'lsiina are ti1 ypica lly
orlbiutlar and obcordlate, while those of R. giuani are
normally oblong and emarginate. In addition, the leaves
of R. vivesian, typically IdrI pale brown and rigidly
"oriaeouis, while those of R. gucana nornally dry pale
gray andl softly suboriaceils. Fruits of A. ri<'esiana arei
aliut 0 Ilniiiong while those of R. gumna are up to
17 lim long. Seedlings of R. -i'esicoa auini( R. galItair
are distinct from one another, as evidenced ',y seeds in
lthie wild and llthose germinated in a greenhouse. The
seedlings of R. rirpesi.ni are half thie size and more
delicate thian lthlose of R. gmnas. .Leaf shape differences
mentioned above are (evyen more nmarked in seedlings
and youing plants.
In herbarium specimens, Retnasi/ wi'IICesiana is
similar in leaf alppearance and fruit size to R.
NoVON 18: 390-394. PIti I.stIttI) ON 2 SitIl�,t:MHt:i 2008.
(ei: 10.3417/2005169


Volume 18, Number 3
2008
Trejo-Torres
Reynosia vivesiana (Rhamnaceae) from
Puerto Rico
doningensis Urban, endemic to the island of IIispa-
niola. Nevertheless, R. domingensis is puberulent and
its leaves are oblong-elliptic and revolute, with the
abaxial fine venation well contrasted. Based on flower
morphology (Schirarend & Hoffmann. 1993). R.
vivesiana seems to belong to a group that includes
R. domingensis. However, this group is characterized
by a tree-like hahit, while R. vivesiana is a shrub.
Reynosia vivesiana Trejo, sp. nov. TYPE: Puerto
Rico. Mun. Gutinica: Barrio Carenero, Guainica
Forest Reserve, Rd. 333, 0.5 km E of Copamiar-
ina entrance, N Iorder of rd., 17 57'N. 66 52'\\
34 m, 17 Oct. 2004. J. C. Trejo 2812 (holotype,
UPR; isotypes, JBSI), K, MO). Figure I.
Ab aliis spciehus portoricensilus Reynosian( Grisrbachl
ranuilis stipulisquc glaibris cl fructilbus parviorihus ca. 9) lmni
dianietro differl; ab R. guamrae Urban ramis elningatis
pIlurilus in coronam conicam diffusamn dispositis et corticc
laevi glauco-cinerasceinti diffel t.
Shrub to 6 ll high; crown typically obconic. diffuse:
stems mulltiple, elongate, to 5 em diam., spreading,
branching typically dichotomous: foliage restrictled to
terminal branches, perennial; bark on stems and twigs
glabrous, glaucous gray. Stipules glabrous, broadly
deltoid-squamiform, ca. 2 mm wide, composed of 2
lateral acutely triangular segments anl I cintral
subulate abaxial appendage; the lateral segments
giving the appearance of paired intrapetiolar stipules
when the abaxial appendage develops into a leaf:
otherwise the appendage commonly caducous, leaving
a 2-pointed stipule: stipels glabrous or scarcely
puberulous, acutely triangular-pyramidal, ca. I mmnn.
axillary. Leaves simple, opposite, decussate: petioles
yellowish green, drying dark brown, slightly canalic-
ulate above. glabrous, ca. 5 X 1.5 nn1 : blades
orbicular to orbicular-oblong, to 5 c:m, base round to
subcordale. alpex cordate to subc(ordate witli a Imiucro
ca. I mm pointing forward, rigidly coriaceous, greeni
and sonewhat shiny adaxially, paler abaxially. drying
pale brown; venation pinnate, reticulate, finely
translucent when fresh, pale when dry, minutely
raised miore evidently adaxially, central vein inm-
pressed adaxially, prominent abaxially. 'lants Imon-
oecious. Flowers aclinomorphic, perigynous, axillary,
fasciculate; pedicels slentler, ca. 8 X 1 mn, greenish
red; buds rhmlboid-globose from the sides, ca.
2 mm diam., apiculate, green tinted with red; hypran-
thium liemispherically cup-shaped, ca. 3 mm diam..
lined with a yellowish green nectariferous disk; sepals
5, triangular, distally and adaxially keeled. ca. 2 mm.
cream-colored adaxially; petals 5, ca. 1 mmi, alternate
to sepals, widely spatulate, base as wide as the
filament base, apex obcordate, lobes truncate-erose
and partially embracing the slamen, cream-colored:
stamens 5, ca. 1.5 mm; filaments ca. 1 mm, reddish
green; anthers ovate, ca. 1 mm, dark brown, dorsi-
fixed, composed of 2 thecae that open longitudinally;
pollen granulate, hyaline; pistil ca. 1.7 mm, green;
ovary globose, ca. 1.2 mm diam., lustrous: ovules 2,
angled, ca. 0.5 ram, white, hasifixed: style cylindric.
slightly widened and angular basally, dull; stigma of 2
joined redl nipples. Fruits globose, ca. 9 mrn. green.
ripening purplish black, with a mucro ca. 1 rnm; stipe
ca. 5 X 1 mm; receptacle, shallowly cup-shaped: seeds
globose to globose-obovate, ca. 7 mmi, basifixed;
endocarp woody-coriaceous, smooth, brown; 1 ilum
navel-like, protruded; testa loosely rugose; endosperm
ruminate: embryo flat, central.
Distribution and IUCN Red List category. The
segregation of Reynosia rilesiari Ifrom R. gluama
heightens the importance of both species from the
conservation standpoint. Reynosiia gunlma (at the time
it included R. iives i(na) was categorized as endan-
gered by Woodbury (1975), as rare by Iittle and
W\ oodbury (1980). and as a critical element by the
Departanlento Id Recursos Naturales y Ambientales
de Puerto Rico (Quevedo et al., 1990). However, it
was not included in the Center for Plant Conservation
(1992) assessment. Its distributional range, now
confined to the Virgin Islands, urgently requires a
new protection category.
Meanwhile, the new ]Reynosia liresiana is known
fromI a single population composed of a few (doeln
individuals scattered in an area of a few square
kilometers inside the (Cuanica Forest Reserve in
Puerto IRico. Even assuming that its potential
geograplhic range ("extent of occurrence"' sensu IICN,
2001) is the tlry limestone forest in southern Puerto
Rico. it covers only 83 knm. Moreover, this zone, one
of the most heavily impacted by humlan ldevelopment
in the island, is currently 30% forested and only 3.8%c
is unler protection (Iugo et al., 2006). Consequently,
following IUCN Red List criteria (IUCN, 2001). R.
z;iesiana is here proposed for legal protection as
Critically Endangered (CR Blah(i.ii.iii)+2ab(i.ii.iii)).
hlbitat and phenology. Reynosia cirlesiarna occurs
from sea level to elevations of 200 m. It is found in a
dry coastal area witl an average rainfall of 800 Imm/
yr.; the geological substrate is Tertiary limestone
(Silander et al.. 1986). Soil is scarce and stony. The
area is covered by low forests or scrub in different
successional stages after five decades of recovering
from intense disturbance (Lugo et al., 1996). Vege-
tation contiguous to the sea is open scrub, withl cacti
colmmon, while vegetation on gentle hills is a sihrubby
forest. Retnosia vivesiana has been found in groups of
up to six individuals, including saplings. Its loose
391


392
Novon
AH HG
A K
I 2mm
Iigure 1 . R< nosia ri, siaiiina Trcjo. A. I Ialil. with lai, of drInrk -. . Twin wil de r il (> of rune . - (. Fertile Iwig with
de tails of stinilmes. - 1). Ferlilf inig with i iis rs i )(of nuils ,ani flnou rs. ,|E. :. |low .r Will lateral. face, amn longitui inal s lition
views, aun delail of slipnels. -h. Petals in nonal incuriinrl posilion (left) and flatllrifd (right). -(;. Stamcniis in anlayial (left)
and sublxorsal (right) viciws. - 11. Pistil. - I. h*ruiting )ranc h. -J. Fruit (left) a dl ,tone (riigli). - K. Seed 11 lateral (left) ;nl
lranvrrse sec lion (right) views. A, (;-I from the holoylp>c.. /. C. Tnjo 28l2 (I H): B, I from J. C. T7(jo 2725 & J. P'upin (J 1|);
.1, K Iroe] J. C. 7'r</o 1 (. lriszrr\ 2710 (1 P\). lllsl>ralion br lobl i Angell.


Volume 18, Number 3
2008
Trejo-Torres
Reynosia vivesiana (Rhamnaceae) from
Puerto Rico
branches with dark green leaves are conspicuous in
the short vegetation canopy. Flowers have been
recorded froIm June through October and Decembner,
and fruits in January, June, July, and October. Flowers
have been observed replete with nectar.
Etymology. The specific epithet of Reynosia
viveiana honors Miguel "Papo" Vives from Quebra-
dillas, Puerto Rico. Vives, formerly a chemistry
teacher, is now widely known as an expert on plant
identification in the island. In the past 30 years, the
has been co/mpanion and collaborator with botanists
responsible for the modern Flora of Puerto Rico. lHe
devotes his time to the study of thle plants of the
island, and he has been an inspiration flor ilnewomers
studying the natural world of Puerto Rico.
Conmmon ICnames. The co/mmnon lnamie '"cascarroya,"
also used for other Rhamnaceae in Puerto Rico, is
recorded on the oldest specimen of Re ynosia vi esia.na
(GAG 30. UPR). Another common name registered on
the specimens L. Gregory 263, 308 (UPR) is "guama,"
which is evidently the source for the specific epithet of
the putative species R. guanma. 1 do not know if the
application of the comnon name "guanma" to the plants
from Puerto Rico comes from a local informant (i.e., a
genuine vernacular name), or if it is a translocation of
the nalme from the Virgin Islands plants.
PI'ratyves. PUERTO RICO. Mun. Gunllica, Barrio
Carenero, Guiiinica Forest Reserve: near lupper end of
liova Las Picuas, 1.2-1.5 kin due N of Playa Canla Gorda, (G.
Proctor & E. lIernindez 16476 (SJ): Ios (Granados trail,
around water tank, ./. C. Trejo & J. Poagd 2725 (UPR);
Maniel Id., betw. Los Granados & Ojo de Agua trails, J. C.
Tr'ijo & C. Irizarry 2738 (UP ), J. C. 7Trjo & C. Irizarry 2740
(tITP); Maniel Rd.. betw. Ojo de Agua & Coiianas trails, J. C.
7Trjo & C. Irizarry' 2741 (UP1), J. C. Tryjo & C(. Irizarry 2742
(T PR): Rd. 333. 0.5 kn E ofCopamarina entrance. N side of
rd.. ./. C. 7'rjo & G. Irizavrry 2743 (UPI'I): Rd. 333, F side of
Cana Gorda beach entrancel, J. C. Trejo, I. .Rirera & A.
Garcia 2767-A (UPR); Cara Gorda, Nov. 1958, R. Woodbury
s.n. (NY. U'PR 26635): close to camp. L. Greglry 3(0 (MAPR,
UPI, U.S). Unspecified localities, whether as Cuanica,
(;Gunica [Forest. (Gutiiica Forest Reserve, or (Gunica Insular
Forest, which may belong to Municipalities of Guanica,
Guavanilla. or Yauo: GAG; 30 (UPR), L. Gregory 263 (UPR),
H. Cowles 2582 (UPK), E. Liulle 13221 (CGi, NY, UPH),
coastal tlickets, A. ,iogier 10791 (US). 26 May 1964, R.
Wtoodbury s.n. (I.PR 26839), 3 Dec. 1969, R. ItWoodbOry s.n.
(NY, UPR 26263), June 1971, R. WoodburyL s.n. (NY, UPR
8533). June 1973, RR.IWoodlhry s.n. (IU fR 1876). 1. Liogier,
P. Liogier & L. F'. Martorell 29487 (UPIt).
The Puerto Rican Bank region, which consists of
the islands of Puerto Rico,, Vieques, Culebra, and the
Virgin Islands, has four species in the genus Reynosia.
Reynosia vi/ie'siana and R. kruigii Urban are both
endemic to Puerto Rico, R. guamat is restricted to the
Virgin Islands, and R. uncinata Urban is known from
Hispaniola. Puerto Rico, and the Virgin Islands.
KEY ]() T t SPEe(:IeS ()1or Retosna NVI'IVt: *lI P tIa'r() RICo 
o
nI' : V\ i' ,IN IsI.AN sI
la. lTw'igs. stipules. and adaxial side of petioles
glabrous; stipels and axils scarcely puberulous or
glabrous: fruits ca. 9 rn t long; seles ca. 7 niIm
long . . . . . . . . . . . . ....... .. ... ... . / . esiani
11b. Twigs, slipules, and adaxial side of petioles
puberulous; slipels and axils densely puberulous;
fruits to 17 nmin long: seeds to 15 min long ....... 2
2a. Leaves to 3 cmn long, typically olbdeloid to
oblong, willh a downward-pointing spiny
llmiI ro. . . . . .. . . . . . . . . . . . . . I(. un lr i
21). Ideaves to 8.5 em long. lanceolate, ovate,
elliptic, oblong, or orbicular, with a forward-
pointing softl mucro .................... 3
3a. Leaves ovale, elliplic, oblong, or orbienu-
lar, base rounlled to sublordale, apex
emarginale to obeordate. ......... R. guafrn
31). Leaves lanceolate, ovate, or elliptic, base
rounded to obtuse, apex shortly acuminate
to cuspidate .................. . R. krugii
Acknowledgments. The superb illustralion is by
Bobbi Angell. Gary Blreckon, Victoria C. Iollowell,
and Rita Lima provided review commenti on the
manuscript. Pedro Acevedo commienited on an earlier
version of the manuscript. Duane Kolterman provided
the altin translation of the species diagnosis. Maarten
Christenhusz helped translate literature from German.
George Rosario assisted with writing in English. Diego
Medan provided relevant comments about the species
morphology. Esther Rojas provided administrative
support. Ilerbaritum logistics were done at UPR, with
the support of Eugenio Santiago. Several herbaria
kindly prepared digital images or grantled loans of
specimens for study at UPH. The study was financed by
project USI)A-I'S-IITF-00CA 11120105001 under co-
operative agreement with (Cidadlanos del Karso, Inc.,
supervised by Ariel Lugo and Abel Vale, respectively.
Funding for the realization of the manuscript was
provided by Consultores en Prevencion y Miligaci6n de
Impactos Ambientales (C)OPREMIA, S.C.P.).
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Plants ol Puerto Rico. Missouri Botanical Garden. St.
Louis.
IUCN. 2001. IUCN Red I ist Categories and Criteria Version
3.1. Prepared by the IUCN Species Survival Commission.
IUCN, Gland. Swilzerland, and (Calimbridge. Uniited
Kingdom.
Iittle, I. I1. Jr. & I. 0. Woodllbry. 1980. Iare and Endemic
Trees of Puerto Rico and tlhe Virgin Islands. Conservation
Research Repori No. 27. USD)A Forest Servi'e. Washing-
ton, D.C.
---- , -- & F. IH. WadsworllT. 1974. Trees of Puerto
Rico and lhe Virgin Islands, Vol. 2. Agriculture Hatndbook
No. 449. USDA Forest Service, Washington, I).C.
Lugo, A. E., 0. Ramos. S. Molina, 1. N. Scalena & I. 1..
Velez Rodrlguez. 1996. A Fiily-three Year Record of Land
Use Change in the G(;nica Forest Biosphere Reserve and
393


394
Novon
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