A new species of Melastomataceae frorm Bolivia is described, illustrated and placed in a phenetic context within Miconia, a genus of 1000 species and about 2000 published names. Miconia quadrialata is readily distinguished from its Congeners by two-colored leaves and sharply four-angular 

and winged branchlets. A search for quadrangular-branched miconias revealed that 12 of 15 such species (in four sections), including the new species, occur in cloud forest in the Andes, raising the question of the adaptive significance of quadrangular branchlets

Beck, Stephan G.

Renner, Susanne S.

English

Open Access LMU

A New Miconia (Melastomataceae) from BoliviaX with Remarks on Angular-laranched Species in the Andes Susanne S. Renller Department of Biology, University of Missouri-St. Louist 8001 Natural Bridge Rd., St. Louis, Missouri 63121^ U.S.A., and Missouri Botanical Garden St. Louis, Missouri 63166, U.S.A. renner@umsl .edu Stephcln G. Bech- Herbario Nacional de Bolivia, Casilla 10077^ La Pazt Bolivia. becks@ceiho.entelnet.ho ABSTR.XCT. A new species of Melastomatac eae frorm Bolivia is describede illustrated and placed in a phenetic context within Micollia, a genus of 1000 species and about 2000 publishecl names. Miconiel uadrialclta is readily distinguishecl from its C'OI1- geners by two-colored leaves and shalply four-an- gular and winged branchlets. A search for qua- drangular-branched miconias revealed that 12 of 15 such species (in four sections)* including the nee speciese occur in cloud forest in the Alldes raising the question of the adaptive significance of qua- clrangular branchlets. Kez- words: adaptive significance, Andes an- gular branches, Boliviae Melastomataceae, Micoslisz. montane forest. In the context of an ongoing floristic project at the Missouri Botanical Garden! the first author vis- ited the Bolivian National Herbarium in La Paz (LPB) and the National Herbarium in Washington (US)* which together contain the most complete col- lections of Bolivian and Neotropical Melastomata- ceae. These visits! and an excursion in the La Paz area, brought o light material of a new species of Miconia Ruiz & Pavon. Miconia is among the larg- est genera of flowering plants, with 1000 species in the best-curated collection (US) and some 2000 published names. In addition, Miconia is unlikelv to be monophyletic (Michelangelie 2002)^ and sev- eral medium-sized genera, such as Clidemia D. Don, Leandra Raddi, Ossaea DC.! and Tococfl Au- blete may have arisen from within it. The entire genus is unlikely to ever be revisedt and over the past 100 years, it has gradually become a black hole in which species are described never to be found again. The new species described here can only be placed in a phenotypic and geographic on- text. It is known from seven collections, all made within a few hours by car from La Paze the first by Alwyn Gentry and colleagues 18 years ago. Over NOVON 13: 1 10-1 12. 2003. the past 11 sear.st he second author collected fer- tile material in salious stages and has sought to cleterllline the speciese ecological amplitude. The ts-o-cololsecl leaves aIlel sharplv four-winged branch- es (see c olor photo at http://www.umsl.edu/ I)ioslenll/ ullder Melastomataceae: Taxonomy) of V. eXlzflflrifllcltfl are highlv distinct, and after sealehillg through tspe collectionse photose and pro- tologues at US. we f'eel confident that it has not alre;a(k been nanle(l. Miconia quadrialata Renner & Beck sp. nov. T\-PE: Bolivia. La Paz: ProsT. Nor Yungas Chuspipata. hacia ex Estacion Ferrocarril, Campamento Andrade 16°18'S 67°48'W, 3010 m, 21 Oct. 2001, S. G. Beck 25988 (ho- lotvpet LPB: isotypes. AAU, CAS, M0, US). Figure 1. Distill(tissillla foliis (oriaceis discoloIibus subtus albis -el stlarllilleis lulllis(lue quadrangularibtls. Shrub or treelet. to 7 m tall; young branchlets sharplv quadrangulart sometimes subsulcate Winge(i. the WiligS 1-2 mm wide; branchlets inflo- resc encese and hvpanthia glabrous. Leaf blades 11.5-15 x S7 c m. 3-nervedn elliptic, the apex shortlv acuminate rarelv obtuset the base acute or Obtuse. rigid chartaceous. above glabrous, below covered bv an appressed tan to white cobwebby minute clentritic-stellulate pubescence. the margin often clrying slightly revolute; petioles (0.5)1-2 cm long. Panicle S13 cm long, with decussate branch- lets. Floral hypanthium 3.5 I mm long! the calyx lobes 1 mm long persistent long after anthesis; pet- als 5. white! about 2 mm long and 1.5 mm broad, their apex emarginate; stamens isomorphic, white; the anthers 1.S2 mm long, truncate and bi-porate, the connective simple, not lobed or appendaged. Berries subglobose. mature blue, dry 5-6 mm diam. This content downloaded  on Fri, 22 Feb 2013 02:44:48 AMAll use subject to JSTOR Terms and ConditionsVolume 13, Number 1 2003 Renner & Beck New Species of Miconia 111 Figure 1. Miconia quadrialata Renner & Beck, drawn from Beck & Renner 25967 and Beck 25988 (MO). a. Habit. b. Branchlet. c. Flower. d. Stamens. Distribution, habitatS and phenology. Miconia quadrialata is only known from the Nor Yungas in Bolivia, where it occurs in cloud forests at 2500- 3100 m alt. with species of Freziera Willdenow (Ternstroemiaceae)? Weinmannia L. (Cunoniaceae), Heslyosmum Swartz (Chloranthaceae), as well as manv Eriaceae and other Melastomataceae. Most collections so far come from rocky outcrops. Mi- This content downloaded  on Fri, 22 Feb 2013 02:44:48 AMAll use subject to JSTOR Terms and Conditions1 1 2 Novon conia quadrialata flowers between mid August and November, and fruits from January to May. The Yungas formation is restricted to west-central Bo- livia and extreme southeastern Peru and is char- acterized by constant high humidity from water droplets and rain deposited by northern trade winds (Beck et al., 1993). Etymology. The epithet alludes to the species' 4-angular and winged branchlets. Miconia quadrialata is unique in combining whitish or tan lower leaf surfaces with sharply qua- drangular branchlets that have 1-2 mm wide wings In leaf shape and venation, it resembles the Peru- vian M. foccosa Cogniaux, but that species has ob- tusely quadrate branches that are densely covered with a felt-like stellate tomentum, which also covers the lower leaf surfaces. Thorough searches in M0 and US revealed that 14 other species of Miconia hasTe strongly quadrangular (sometimes in addition winged or sulcate) stems, but that none at the same time have bi-colored leaves. The geographic and altitudinal ranges of the 14 quadrangular-branched species (given below) suggest that this character may be particularly common in montane forests, although four of the species also occur below 500 m. An intriguing question is what may select for the evolution of angular and winged branches, and if as many instances of parallel evolution are in- volved as suggested by the current assignment of these species to 4 of the 11 sections of Miconia (Cogniaux, 1891). A possible adaptive value (T. Feild, pers. comm., May 2002) is that the square internodes relate to how branchlets break during trauma. Many Chloranthaceae in similar habitats also have square stems coupled with septate-mod- ular branchlets, such that they break in predictable ways when traumatized by falling canopy debris. (The 14 quadrangular-branched species of Miconia so far known are M. alata DC. from 50 to 1000 m alt. in Venezuelan Amazonia and adjacent Brazil; M. aligera Wurdack from cloud forest at 2080 m in the department of Cuzeo, Peru; M. dissimulans Wurdack from cloud forest at 2700-3350 m in southern Ecuador; M fiaccida Gleason from 1200 to 1900 m in Huanuco and Pasco, Peru; M. fZoccosa Cogniaux from 2500 to 3000 m in Pasco; M. glu- tinosa Cogniaux from 2400 m in Puno, Peru; M. incachacana Wurdack from 2200 m in Cochabam- ba, Bolivia; M. monzoniensis Cogniaux from 2400 m in Huanuco [this includes M. pterogona Glea- son]; M. pterocaulon Triana from 120 to 950 m in Costa Rica, Venezuela, Colombia, Ecuador, and Peru; M. quadrangularis (Swartz) Naudin from 500 to 2300 m in Jamaica; M. reducens Triana from 50 to 1500 m in Nicaragua southeast to Ecuador and Venezuela; M. robinsoniana Cogniaux from 400 to 500 m elevation on the Galapagos islands but also occurring at 2500-3000 m in Panama; M. subno- dosa Triana from 150 to 1700 m in Colombia, Ec- uador, and Bolivia; and M. sulcata Macbride from around 2000 m in Junfn, Peru. At least three of the listed species, Miconia reducens, M. robinsoniana, and M. subnodosa, are part of a messy species com- plex that also includes M. aponeura Triana from 1400 m in central Colombia, with winged inter- nodes [F. Almeda, pers. comm.]. Sharply two- winged branchlets are known from M. micayana Wurdack [ = Amphitoma flavescens Gleason], oc- curring from 1800 to 2300 m in Cauca, Colombia, and from M. paradoxa Triana, occurring from 500 to 1000 m Minas Gerais, Brazil.) Paratpes. BOLIVIA. La Paz: Nor Yungas, near Chus- pipata, 2800 m, 13 Jan. 1984, Gentry et al. 44195 (LPBf MO, US); 22.5 km above Yolosa towards Chuspipata, 2560 m, 27 Feb. 1990, Beck 14995 (LPB, US); past Unduavi, CotapataS 1 hr. along downhill trail, 3100 m, 29 May 1994, Beck 21386 (LPB, US); past Unduavi, Cotapata, 3000 m, 11 Sep. 1994, Beck 21457 (LPB, M, MO, NY, QCA US); between Cotapata nd Chuspipata, 3000 m, 2 Nov. 1996, Bech^ 22775 (LPB, US), Cotapata, 3000 m, 5 Aug. 2001, Beck & Renner 25967 (LPB, MO). Acknowledgments. We thank Barbara Alongi for the drawing, Dan Nicolson for checking the Latin, and Frank Almeda for comments on the manu- script. Literature Cited Beck, S. G., T. J. Killeen & E. Garcia E. 1993. Vegetaci6n de Bolivia. Pp. S25 in T. J. Killeen, S. G. Beck & E. Garcia E. (editors), Gufa de Arboles de Bolivia. Her- bario Nacional de Bolivia, La Paz, and Missouri Botan- ical Garden, St. Louis. Cogniaux, A. 1891. Melastomaceae. ln A. & C. de Can- dolle. Monographie phanerogamarum 7: 1-1256. Michelangeli, F. A. 2002. Phylogenetic relationships in the Miconieae: Evidence from morphological and ITS sequence data. 2002 AIBS meetings, abstract published online at http://www.botany2002.org/. This content downloaded  on Fri, 22 Feb 2013 02:44:48 AMAll use subject to JSTOR Terms and Conditions

A new Miconia (Melastomatacaeae) from Bolivia, with remarks on angular-branched species in the Andes

Universität München: Elektronischen Publikationen

A New Miconia (Melastomataceae) from BoliviaX with Remarks on 
Angular-laranched Species in the Andes 
Susanne S. Renller 
Department of Biology, University of Missouri-St. Louist 8001 Natural Bridge Rd., St. Louis, 
Missouri 63121^ U.S.A., and Missouri Botanical Garden St. Louis, Missouri 63166, U.S.A. 
renner@umsl .edu 
Stephcln G. Bech- 
Herbario Nacional de Bolivia, Casilla 10077^ La Pazt Bolivia. becks@ceiho.entelnet.ho 
ABSTR.XCT. A new species of Melastomatac eae 
frorm Bolivia is describede illustrated and placed in 
a phenetic context within Micollia, a genus of 1000 
species and about 2000 publishecl names. Miconiel 
uadrialclta is readily distinguishecl from its C'OI1- 
geners by two-colored leaves and shalply four-an- 
gular and winged branchlets. A search for qua- 
drangular-branched miconias revealed that 12 of 15 
such species (in four sections)* including the nee 
speciese occur in cloud forest in the Alldes raising 
the question of the adaptive significance of qua- 
clrangular branchlets. 
Kez- words: adaptive significance, Andes an- 
gular branches, Boliviae Melastomataceae, Micoslisz. 
montane forest. 
In the context of an ongoing floristic project at 
the Missouri Botanical Garden! the first author vis- 
ited the Bolivian National Herbarium in La Paz 
(LPB) and the National Herbarium in Washington 
(US)* which together contain the most complete col- 
lections of Bolivian and Neotropical Melastomata- 
ceae. These visits! and an excursion in the La Paz 
area, brought o light material of a new species of 
Miconia Ruiz & Pavon. Miconia is among the larg- 
est genera of flowering plants, with 1000 species in 
the best-curated collection (US) and some 2000 
published names. In addition, Miconia is unlikelv 
to be monophyletic (Michelangelie 2002)^ and sev- 
eral medium-sized genera, such as Clidemia D. 
Don, Leandra Raddi, Ossaea DC.! and Tococfl Au- 
blete may have arisen from within it. The entire 
genus is unlikely to ever be revisedt and over the 
past 100 years, it has gradually become a black 
hole in which species are described never to be 
found again. The new species described here can 
only be placed in a phenotypic and geographic on- 
text. It is known from seven collections, all made 
within a few hours by car from La Paze the first by 
Alwyn Gentry and colleagues 18 years ago. Over 
NOVON 13: 1 10-1 12. 2003. 
the past 11 sear.st he second author collected fer- 
tile material in salious stages and has sought to 
cleterllline the speciese ecological amplitude. The 
ts-o-cololsecl leaves aIlel sharplv four-winged branch- 
es (see c olor photo at http://www.umsl.edu/ 
I)ioslenll/ ullder Melastomataceae: Taxonomy) of 
V. eXlzflflrifllcltfl are highlv distinct, and after 
sealehillg through tspe collectionse photose and pro- 
tologues at US. we f'eel confident that it has not 
alre;a(k been nanle(l. 
Miconia quadrialata Renner & Beck sp. nov. 
T\-PE: Bolivia. La Paz: ProsT. Nor Yungas 
Chuspipata. hacia ex Estacion Ferrocarril, 
Campamento Andrade 16°18'S 67°48'W, 
3010 m, 21 Oct. 2001, S. G. Beck 25988 (ho- 
lotvpet LPB: isotypes. AAU, CAS, M0, US). 
Figure 1. 
Distill(tissillla foliis (oriaceis discoloIibus subtus albis 
-el stlarllilleis lulllis(lue quadrangularibtls. 
Shrub or treelet. to 7 m tall; young branchlets 
sharplv quadrangulart sometimes subsulcate 
Winge(i. the WiligS 1-2 mm wide; branchlets inflo- 
resc encese and hvpanthia glabrous. Leaf blades 
11.5-15 x S7 c m. 3-nervedn elliptic, the apex 
shortlv acuminate rarelv obtuset the base acute or 
Obtuse. rigid chartaceous. above glabrous, below 
covered bv an appressed tan to white cobwebby 
minute clentritic-stellulate pubescence. the margin 
often clrying slightly revolute; petioles (0.5)1-2 cm 
long. Panicle S13 cm long, with decussate branch- 
lets. Floral hypanthium 3.5 I mm long! the calyx 
lobes 1 mm long persistent long after anthesis; pet- 
als 5. white! about 2 mm long and 1.5 mm broad, 
their apex emarginate; stamens isomorphic, white; 
the anthers 1.S2 mm long, truncate and bi-porate, 
the connective simple, not lobed or appendaged. 
Berries subglobose. mature blue, dry 5-6 mm diam. 
This content downloaded  on Fri, 22 Feb 2013 02:44:48 AM
All use subject to JSTOR Terms and Conditions
Volume 13, Number 1 
2003 
Renner & Beck 
New Species of Miconia 
111 
Figure 1. Miconia quadrialata Renner & Beck, drawn from Beck & Renner 25967 and Beck 25988 (MO). a. Habit. 
b. Branchlet. c. Flower. d. Stamens. 
Distribution, habitatS and phenology. Miconia 
quadrialata is only known from the Nor Yungas in 
Bolivia, where it occurs in cloud forests at 2500- 
3100 m alt. with species of Freziera Willdenow 
(Ternstroemiaceae)? Weinmannia L. (Cunoniaceae), 
Heslyosmum Swartz (Chloranthaceae), as well as 
manv Eriaceae and other Melastomataceae. Most 
collections so far come from rocky outcrops. Mi- 
This content downloaded  on Fri, 22 Feb 2013 02:44:48 AM
All use subject to JSTOR Terms and Conditions
1 1 2 Novon 
conia quadrialata flowers between mid August and 
November, and fruits from January to May. The 
Yungas formation is restricted to west-central Bo- 
livia and extreme southeastern Peru and is char- 
acterized by constant high humidity from water 
droplets and rain deposited by northern trade winds 
(Beck et al., 1993). 
Etymology. The epithet alludes to the species' 
4-angular and winged branchlets. 
Miconia quadrialata is unique in combining 
whitish or tan lower leaf surfaces with sharply qua- 
drangular branchlets that have 1-2 mm wide wings 
In leaf shape and venation, it resembles the Peru- 
vian M. foccosa Cogniaux, but that species has ob- 
tusely quadrate branches that are densely covered 
with a felt-like stellate tomentum, which also covers 
the lower leaf surfaces. Thorough searches in M0 
and US revealed that 14 other species of Miconia 
hasTe strongly quadrangular (sometimes in addition 
winged or sulcate) stems, but that none at the same 
time have bi-colored leaves. The geographic and 
altitudinal ranges of the 14 quadrangular-branched 
species (given below) suggest that this character 
may be particularly common in montane forests, 
although four of the species also occur below 500 
m. An intriguing question is what may select for 
the evolution of angular and winged branches, and 
if as many instances of parallel evolution are in- 
volved as suggested by the current assignment of 
these species to 4 of the 11 sections of Miconia 
(Cogniaux, 1891). A possible adaptive value (T. 
Feild, pers. comm., May 2002) is that the square 
internodes relate to how branchlets break during 
trauma. Many Chloranthaceae in similar habitats 
also have square stems coupled with septate-mod- 
ular branchlets, such that they break in predictable 
ways when traumatized by falling canopy debris. 
(The 14 quadrangular-branched species of Miconia 
so far known are M. alata DC. from 50 to 1000 m 
alt. in Venezuelan Amazonia and adjacent Brazil; 
M. aligera Wurdack from cloud forest at 2080 m in 
the department of Cuzeo, Peru; M. dissimulans 
Wurdack from cloud forest at 2700-3350 m in 
southern Ecuador; M fiaccida Gleason from 1200 
to 1900 m in Huanuco and Pasco, Peru; M. fZoccosa 
Cogniaux from 2500 to 3000 m in Pasco; M. glu- 
tinosa Cogniaux from 2400 m in Puno, Peru; M. 
incachacana Wurdack from 2200 m in Cochabam- 
ba, Bolivia; M. monzoniensis Cogniaux from 2400 
m in Huanuco [this includes M. pterogona Glea- 
son]; M. pterocaulon Triana from 120 to 950 m in 
Costa Rica, Venezuela, Colombia, Ecuador, and 
Peru; M. quadrangularis (Swartz) Naudin from 500 
to 2300 m in Jamaica; M. reducens Triana from 50 
to 1500 m in Nicaragua southeast to Ecuador and 
Venezuela; M. robinsoniana Cogniaux from 400 to 
500 m elevation on the Galapagos islands but also 
occurring at 2500-3000 m in Panama; M. subno- 
dosa Triana from 150 to 1700 m in Colombia, Ec- 
uador, and Bolivia; and M. sulcata Macbride from 
around 2000 m in Junfn, Peru. At least three of the 
listed species, Miconia reducens, M. robinsoniana, 
and M. subnodosa, are part of a messy species com- 
plex that also includes M. aponeura Triana from 
1400 m in central Colombia, with winged inter- 
nodes [F. Almeda, pers. comm.]. Sharply two- 
winged branchlets are known from M. micayana 
Wurdack [ = Amphitoma flavescens Gleason], oc- 
curring from 1800 to 2300 m in Cauca, Colombia, 
and from M. paradoxa Triana, occurring from 500 
to 1000 m Minas Gerais, Brazil.) 
Paratpes. BOLIVIA. La Paz: Nor Yungas, near Chus- 
pipata, 2800 m, 13 Jan. 1984, Gentry et al. 44195 (LPBf 
MO, US); 22.5 km above Yolosa towards Chuspipata, 2560 
m, 27 Feb. 1990, Beck 14995 (LPB, US); past Unduavi, 
CotapataS 1 hr. along downhill trail, 3100 m, 29 May 
1994, Beck 21386 (LPB, US); past Unduavi, Cotapata, 
3000 m, 11 Sep. 1994, Beck 21457 (LPB, M, MO, NY, 
QCA US); between Cotapata nd Chuspipata, 3000 m, 2 
Nov. 1996, Bech^ 22775 (LPB, US), Cotapata, 3000 m, 5 
Aug. 2001, Beck & Renner 25967 (LPB, MO). 
Acknowledgments. We thank Barbara Alongi for 
the drawing, Dan Nicolson for checking the Latin, 
and Frank Almeda for comments on the manu- 
script. 
Literature Cited 
Beck, S. G., T. J. Killeen & E. Garcia E. 1993. Vegetaci6n 
de Bolivia. Pp. S25 in T. J. Killeen, S. G. Beck & E. 
Garcia E. (editors), Gufa de Arboles de Bolivia. Her- 
bario Nacional de Bolivia, La Paz, and Missouri Botan- 
ical Garden, St. Louis. 
Cogniaux, A. 1891. Melastomaceae. ln A. & C. de Can- 
dolle. Monographie phanerogamarum 7: 1-1256. 
Michelangeli, F. A. 2002. Phylogenetic relationships in 
the Miconieae: Evidence from morphological and ITS 
sequence data. 2002 AIBS meetings, abstract published 
online at http://www.botany2002.org/. 
This content downloaded  on Fri, 22 Feb 2013 02:44:48 AM
All use subject to JSTOR Terms and Conditions


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A new Miconia (Melastomatacaeae) from Bolivia, with remarks on angular-branched species in the Andes

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