TAXONOMY OF NORTH AMERICAN SPECIES OF OLDENLANDIA (RUBIACEAE)

2006·15.8 MB·English

by  Edward E Terrell

TAXONOMY
OF NORTH AMERICAN
OF
SPECIES
OLDENLANDIA
(RUBIACEAE)
Edward
Robinson
E.Terre Harold
1
Research Associate Curator
Deportment
of Systematic Biology-Botany Department of Systematic Biology-Botany
Museum
Museum
National of Natural l-listory National of Natural History
Smithsonian
Institution Smithsonian
Institution
DC
Washington, DC. 2001 3-701 Washington^ 20013-7012^
2^ U.S.A. U.S.A.
ABSTRACT
This paper presents a taxonomic treatment of nine species of Oldenlandia occurring as native or
adventive in United States or Mexico. The subgenus Oldeyilandia is represented by four species: 0.
corymbosa, 0. lancijolia, 0. unijlora, and 0. hoscii. Subgenera for the remaining species are undeter-
A
mined. Four species are native to Mexico; O.pringlei, 0. rriicrotheca, O. ovata, and 0. drymarioides.
ninth species, 0. salzmannii, is native to South America and adventive in northwest Florida and
adjacent Alabama. Keys, descriptions, and scanning electron micrographs of the seeds are provided.
RESUMEN
Este articulo presenta un tratamiento taxonomico de nueve especies de Oldenlandia que ocurren
como
nativas o adventicias en Estados Unidos o Mexico. El subgenero Oldenlandia esta representado
por cuatro especies: O. corymhosa, 0. lancijolia, 0. uniflora y 0., hoscii. Los subgeneros para la especie
restante son indeterminados. Cuatro especies son nativas de Mexico: 0. pringlei, O. microtheca, 0.
Una
ovata y O. drymarioides. novena especie, 0. salzmannii, es nativa de Suramerica y adventicia en
Alabama
el noroeste Florida y adyacente. Se proporcionan claves, descripciones, y fotografias al
microscopio electronico de barrido de las semillas.
Oldenlandia (Hedyotideae; Rubiaceae) genus about 100
L. a of species
is
(Verdcourt worldwide warm, and
1976) distributed in subtropic, tropic regions.
named
was
by Linnaeus Henrik Bernard Oldenlan, Danish physician
for a
It
and
botanist of the 17th century
Bremekamp's monograph
(1952) of the African species of Oldenlandia rec-
ognized 61 species in 16 subgenera. Verdcourt (1976) treated 37 species of
Oldenlandia and
in the Flora Tropical East Africa, 25 species (1989) in the
of
Zamhesiaca
Flora region. Other authors have recognized 12 species West
in
&
Tropical Africa (Hepper Keay 1963) and 7 in Gabon (Halle 1966). Lewis (1965)
commented
more
that Africa has Oldenlandia species than exist in other
all
combined and
tropical regions the center of morphological diversity
is its
was
Oldenlandia considered as only a subgenus of Hedyotis by Fosber
(1943) in his study of the Polynesian Hedyotis species; however, the foreign
f lo-
Address for correspondence: 14001 Wildwood Drive, Silver Spring, Maryland 20905, U.S.A
SIDA 305 -329. 2006
22(1):
BRIT.ORG/SIDA
306 22(1)
and American have Oldenlandia
ras cited here recent regional floras all treated
as a distinct genus.
among
problems
Terrell (1996) discussed of generic limits Hedyoiis,
Houstonia, and Oldenlandia while revising Houstonia, a genus of 20 North
American and Robinson (2003) rcumscribed Hedyotis subge-
species. Terrell ci
new
nus Hedyotis, an Asian subgenus, and recognized the genus Exallage as a
A
subgenus of Oldenlandia. synopsis of the United States species of
Oldenlandia (Terrell 1990) treated five species.
Molecular studies found Oldenlandia to be paraphyletic (Bremer 1996) or
&
polyphyletic (Andersson Rova species were widely distributed in
1999).
Its
Manen
the rubiaceous lineage in what Bremer (1996) and Bremer and (2000)
name
treated as the tribe Spermacoceae, that having priority over the
members
Hedyotideae within which was nested. Tested Oldenlandia are
ol
it
and
dispersed in the slightly paraphyletic part of that lineage that Terrell
Wunderlin (2002), Andersson and Rova (1999) and the present authors would
continue to treat as a separate tribe Hedyotideae.
Lewis (1965) described the pollen of Oldenlandia and other genera in de-
Oldenlandia small medium-sized and (2-)3(4-5)
In the pollen are or
tail.
aperturate.
AND METHODS
MATERIALS
many
The taxonomic treatment based on loans of herbarium specimens, as
is
and
cited in the representative collections. All species except 0. pringlei 0.
and
drymarioides were seen in living condition. Oldenlandia microtheca O.
was
ovata were studied and collected in Mexico. Oldenlandia salzmannii ob-
served in greenhouse plants. The North American species of subg. Oldenlandia
m
were collected various parts of their ranges.
Previous work on Hedyotideae has shown that capsule and seed morphol-
we
ogy are especially important in taxonomic studies. In the present work ex-
amined the seeds of each species by scanning electron microscopy The results
summary more
of this study are presented below in the of the significant char-
each
acters of species.
AND
RESULTS DISCUSSION
Oldenlandia subgenus Oldenlandia
The worldwide weed
type species of Oldenlandia, 0. corymbosa, a well estab-
is
members
lished in eastern North America. Other of subgenus Oldenlandia in-
and
clude O. laneifolia, adventive in Mexico, the native U.S. species, 0. unijlora
and The from two having
O. hoscii. latter tw^o species differ the other in axillary
and terminal glomerules and slightly smaller corolla and other flower parts,
but otherwise have similar characteristics (Table
1).
TERRELL AND ROBINSONJAXONOMY OF NORTH AMERICAN OLDENLANDIA
307
Table Characters of species subg.Oldenlandia.
1. in
corymbosa
lancifolia unlflora
boscli
Duration annua
perennial/ann. annua
perennial
Habit
erect/ erect/decumb
prostr.
erect/prostr. sprdg./prostr.
mm
Width
Leaves, 1-9 2-12
2-11 1-5
mm
Stipules,
L, to 2 to 1,5 to 4 to 2
Inflorescence cymes
pedicellate pedicellate cymes glomerules
glomerules
mm
-2
Corollas,
L, 1.5-2.5 0.7-1.3 0.7-1.3
Shape
rotate/tubular
rotate/tubular
rotate rotate
mm
Tube
0.5-1,0
L, 0.5-1.0 0.1-0.3
0.1-0.3
mm
Lobes,
L, 0.5-1,0 0.5-1.5 0.7-1.2
to 0.7
mm
Anthers,
L, 0,2-0.3 0,4-^0,6 0.1-0.3
0.1-0.3
mm
Filament,
L, 0.1-0.3 0.2-0.5 0.2-0.4
ca,0.2
mm
Lobes,
Stig. L, 0.3-1.0 0.5-1 than
than
.2 less 0,6 less 0.5
mm
Capsules,
1-2.2
L, 1.6-3.5 1-2.5
1,5-3,0
mm
Seeds,
L, 0.2-0. 0.25-0.35 0.2-0.3
0.1-0.3
The
following description of subgenus Oldenla ndia based mainly on
the
is
North American
species.
Small annual cm
or perennial herbs usually than 80 Stems
less
slen-
tall.
mm
decumbent, 3-60
der, erect, or prostrate. Leaves
long, opposite, sessile or
mm
petiolate, usually linear to ovate. Stipules 1.5-4 long, mterpetiolar, adnate
uath
to leaf bases, 1-few marginal
teeth, setae, or fimbriae. Inflorescences are of
two
types, either open, pedicellate, with few-flowered cymes from and
axillary
terminal nodes
or else the flowers sessile or subsessile in axillary and terminal
glomerules. Flowers
tetramerous, isostylous (homostylous) our but
in species,
m
subgenus may
species this elsewhere be Hypanthium
heterostylous.
(calyx
mm
cup) cup-shaped
or hemispheric. Corollas 0.7-2.5(-4)
long, rotate or tubu-
mm
lar, white or tinted pink or purple, glabrous externally; tube 0.1-LO
long,
mm
mm
shorter or longer than the 4 lobes; lobes 0.5-1.5 long. Anthers 0.1-0.6
long, dorsifixed, sessile or on short filaments inserted on corolla tube at or be-
mm
low
corolla sinuses. Stigmas 2-lobed, 0.2-1.2
long, styles filiform or thick-
ened, glabrous. Ovules on X mm,
peltate placentae. Capsules 1-4
1-3.5
bilocu-
usually subglobose, fused with hypanthium, 3/4
lar, to fully inferior, dehiscir
^
mm
loculicidally or also septicidally Seeds 50-100 more
or per capsule, 0.1-0.4
brown
long, black, or tan, trigonous or conoidal-trigonous,
basal face oval or
more
elliptical, often or less flat, lateral faces slightly or somewhat concave,
hilum
punctiform apex
at of the apical angle, testa reticulate, areoles
(cells)
usually polygonal, areole walls low, rounded, indistinct, testa surface often ver-
rucose (densely covered with minute
papillae). Placenta fused with septum
about 1/3-1/4 of the distance above Chromosome number
base. x =
its
9.
When
COmnared
with the nrher snpripc: TTi^hlp 1') rlnp nnimiP nr ^^'n^^CliO^
BRIT.ORG/SIDA 22{1)
308
Comparison Oldenlandia
Table of taxa.
2. foiji'
Salzmannii Microtheca
subg.Oldenlandia Pringlei
one one three
examined four
No. of species
erect/decumbent
creeping
Habit erect/prostrate ascdg./prostr.
rhizomatous
mm
Leaves Lxw, 3-60 X 1-12 3-15 .3-2 1.5-5,2 X 0.7-3 3-40 X 1-20
mm
0.5-2
Stipules L 1.5-4 0.3 to 0.5
cymose
cymose
Inflorescence cymose/glomer. solitary
mm
Corollas L 0.6-2.5 4.0-8.5 2-5.5 2.5-7
Cor. shape rotate/tubula subsalv./funne subsalverform funnelform
mm
1-3
Cor. tube L 0.1-1.0 2-5 1-2.2
mm
1-3.2 1.5-4
Cor. lobes L 0.5-1.5 1.5-3.5
mm
Anthers 0,1-0.6 0.8-1.3 0.5-0.8 0.^-1
L
W
Capsules X 1—3.5 X 1-4 2-3 X 2-2.5 X 1-3 5-3.5
L 1.5 1.5
4-14 0-34
Seeds 50-100 +
no./caps.
Seeds L/dia.mm 0.1-0.4 0.2-0.4 0,3-0.5 0.4-0.
Seeds shape trigonous subglob/ovoid trigonous angulate/irreg
conoidal
none
poygonal poiygona poiygona
Seeds, areoles
none
Areole walls low, rounded thick, sinuous distinct
not
Testa reticulate reticulate reticulate
'eticulate
smooth entangled
Testa surface verrucose/other verrucose
strands
=
Chrom.no.x 15 11,12
9
Oldenkrndicnnclude the following: Inflorescence either pedicel-
features of subg.
late in small cymes at the nodes or else flowers subsessile in glomerules; f low^ers
mm
usually isostylous (homostylous); corollas small, often 0.7-2.5 long, rotate
mm
50-100 more
or tubular; anthers 0.1-1.0 long; seeds or per capsule, 0.1-0.4
mm
chromosome num-
walls rounded,
long, trigonous, areole low, indistinct;
many
X = worldwide.
ber 9 species
in
Seed data subgenus are described and illustrated in Figures 1-3.
for this
and
Figure shows typical trigonous oldenlandioid seeds in 0. corymhosa 0.
1
A
onal areoles. basal face
7
'/'
The
often flat (Fig. IC) and the lateral faces are flat or slightly concave. apical
is
An
hilum shown in Fig. ID. enlargement of part of an areole (Fig. IF) has a
is
with low
verrucose testa areole walls.
Two Linnaean species, the Asian 0. herhacea and the African 0. umhellata
lackmg
show trigonous seeds with concave lateral faces the verrucose
(Fig. 2)
smooth
surface; instead with a coarsely papillose (Fig. 2C) and an apparently
surface 2D).
(Fig.
wdth concave
s trigonous seeds (Fig. 3) a lateral
^n
and low For
densely papillose surface indistinct areole
face (Fig. 3B,C), a vv^alls.
TERRELL AND ROBINSON. TAXONOMY OF NORTH AMERICAN OLDENLANDIA
309
J. Seeds of species examined by SEM.A-D, 0Wen/Gnrf/acorym/)05a, A, Procfo^
Fig OWe/)/fl/?(//fl
Lehng 6891.2 (NCU), Florida; C. Standley 52679 (US), Honduras. E-F. Oldenlandialancifolia, Vasquezetai. V-U24 (XAL),
C
Mexico. A. Views of 5 seeds; B, E. End views; Tilted showing basal and lateral surfaces; D. Hilum at apex; Areoles
F.
enlarged.
310 BRIT.ORG/SIDA 22(1)
Fig. 2. Seeds of Oldenlandio species examined by SEM. A, C, Oldenlandia herbacea, Fosberg 40749 (US), Nigeria, B, D,
Oldenlandia umbellata, Fosberg 51929 (US), Ceylon. A-B. End views; C-D, Areoles enlarged.
shown
comparison with seeds of subgenus Olden Jandia two trigonous seeds are
(Fig. 3D,E) from the Asian species, O. lapcyrousii, belonging to the subgenus
&
Exallage Robinson
(Terrell 2003).
Oldenlandia species not in subgenus Oldenlandia
Table 2 summarizes the more important characters of the remaining species as
well as those of subgenus Oldenlandia. The remaining species are not readily
new
more
assignable to subgenera until data are knowMT about other genera.
Oldenlandia San Luis Mexico. more
pringlei, restricted to Potosi, sig-
is Its
nificant characters are as loUows: Plants small, herbaceous, rhizomatous, as-
cending or prostrate; leaves Hnear; flowers in open, few-flowered cymes,
mm
heterostylous; corollas 4.0-8.5 long, subsalverform in contrast with the
m
small, rotate or tubular corollas present subg. Oldenlandia] anthers 0.8-1.3
mm
30-50
long; seeds per capsule, subglobose, ellipsoid, or ovoid instead of
TERRELL AND ROBINSONJAXONOMY OF NORTH AMERICAN OLDENLANDIA
311
hQjSeeis
of Oldenlandia speQeseKa\r]meA by Sil^,A-C,Oldenlandiauniflora, Leonard
E. Oidenlandia fapeyrousii, Smith 9079 (US), Fiji. A, D, E, end views; B-C.Two views of enlarged areoles.
and and chromosome number
trigonous, areole wall rather thick sinuous; not
known. and
Ventral dorsal view^s of ellipsoid seeds w^ith their sinuous thick-
tlie
walled shown 4 The
areoles are in Figure A,B. ventral view^ show^s the centric
punctate hilum.
Oidenlandia salzniannh South American
a species established in north-
is
western Florida and adjacent Alabama. The plants are herbaceous, creeping
may
perennials, whereas other Oidenlandia species be prostrate but rarely or
mm mm
not creeping; leaves small, L5-5.2 long; stipules small, to 0.5 long; flow-
mm;
X
ers solitary, pedicellate; corollas subsalverform; capsules small,
1.5 1.5
mm
4-14
seeds only per capsule, 0.3-0.5 long, trigonous, areole walls distinct;
312 BRIT.ORG/SIDA 22(1)
Fig, 4. Seeds of Oldenlandia species examined by SEM. A-B. Oldenlandia pringfei, Pringfe 3758 (US), Mexico. C-F.
Oldenfandia safzmannii, Burkhalter & Hond 6537 (UWFB), Florida. A. ventral view; B. dorsal view/; C. side view; D. hilar
area; E, basal surface; F. areoles.
TERRELLANDROBINSONJAXONOMYOF NORTH AMERICAN OLDENLANDIA 313
m
chromosome number number
n = 2n = 30, a unique Hedyotideae (Lewis
15;
1966b). Figure 4 C-E shows a trigonous seed with concave lateral faces, an api-
cal hilum, and polygonal areoles with straight walls.
The Oldenlandia microtheca group includes three Mexican species, 0.
microtheca, 0. ovata, and 0. drymarioidcs. Their relationships to other species
named
groups somewhat but they have been Oldenlandia
or are in question,
and appear genus than any Oldenlandia drymarioides
closer to that to other. is
with resemblance
a rarely collected species a close to 0. ovata. tentatively
It is
considered
a distinct species.
may
The be summarized
characteristics (Table 2) of the three species as
foUow^s: Small herbs, annual or perennial; flowers in cymes, heterostylous; co-
mm mm
rollas 2.5-7.0 long, funnelform; capsules 1-3 long; seeds 10-34 per cap-
mm
hon-
0.4-0.7 long, angulate or irregularly conoidal, surface irregularly
sule,
eycombed or alveolate, areoles lacking, coalesced, replaced by entangled
vermiform strands; chromosome number x = These species are notable
12.
11,
for their unusual seeds (Fig. which differ conspicuously from those of all
5),
The and
other Oldenlandia species. seeds lack the usual reticulate testa instead
have a jumbled mass of entangled vermiform strands, a condition here referred
running These
to as coalescent areoles in reference to their together (Fig. 5 C,F).
and opposed subgenus Oldenlandia and
seeds are larger fewer per capsule as to
show a range of shapes from irregularly and obtusely angulate to irregularly
known
conoidal. Coalescent areoles and a chromosome number of x = 11 are in
Chamisme and
Houstonia subgenus section Ericotis of southwestern U.
S.
Mexico but those species are otherwise quite distinct from the 0.
(Terrell 1996),
microtheca group.
TAXONOMIC TREATMENT OF NORTH AMERICAN
SPECIES
&
Oldenlandia L., Sp. Pi. 119.1753. Gewntogea Cham. Schlecht., Linnaea 4:1541829. Type: O.
corymbosa designated by tiitchcock and Green (1929). Hcdyoiis corymhosa (L.) Lam., Tabl.
L.,
Encycl. 1:272. 1792, Lectotype: Plumier, Nov. PI. Amer. t.36. 1703, cited by Jarvis et al (1993)
and Verdcourt (1976). Four other generic synonyms were listed by Scandley (1918).
KEY TO UNITED OE OLDENLANDIA, NATIVE OR ADVENTIVE
STATES SPECIES
mm
matTorming long;adventivein northwest
Creeping, perennials.leaves 1.5-5.2
1.
and adjacent Alabama 6.0.salzmannii
Florida
spreading, decumbent, or prostrate annuals or perennials; leaves (3-)5-60
Erect,
1
mm
long; native or widely established species.
mm
Flowers and capsules on pedicels more than 3 long, not in glomerules
2.
I.O.corymbosa
Flowers and capsules in axillary or terminal glomer^ules, sessile or pedicels less
2.
mm
than 3 long.
mm
Annual; leaves 2-1 wide, ovate to 3.0. uniflora
elliptic
3.
1
mm
woody
Perennial with tap root; leavesl-3(-5) wide, linear to narrowly
3.
0.boscii
4.
elliptic
314 BRIT.ORG/SIDA
22(1)
Fig. 5. Seeds of Ofdenlandia species examined by SEM. A-C. Oldenlandia miaotheca, A-B. Schiede 390 (K), Mexico; C.
U920
&
Pennell (US), Mexico. D-F. Oldenlandia ovata, Crutchfield Johnston 5600B (TEX), Mexico. A-B. side views; D-E.
ventral views including hilar areas; C-F. enlargement of coalesced areoles.