Table Of Content—
Michigan Herb. 24: 173 1X7. 2005.
/.
NEW FROM
EUPHORBIACEAE
MEXICO.
II.
W. Steinmann
Victor
InstitutodeEcologia,A.C.
Centro Regional del Bajio, A.P. 386
61600 Patzcuaro, Michoacan, Mexico
Recent estimates of the number of species of Euphorbiaceae in Mexico vary
and Michoacan
from 782 (Steinmann 2002) to 826 (Martinez et 2002), the state of
al.
Rodriguez and Espinosa reported the
possesses a rich diversity of these. (1996)
and genera whereas Martinez
presence of 127 species 19 for the state, et al. (2002)
number
reported 164 species and 20 genera. estimate that the actual of taxa is closer
I
value and even higher with about 185 species and 21 genera pres-
to the latter slightly
Here new species are described from Michoacan.
ent. six
Croton W. Steinmann, nov. Type: Mexico. Michoacan: Mpio.
atrostellatus V. sp.
NE
km
Angamacutiro, along the road from Panindicuaro to Villachuato, 18
NE
km
Guadalajara-Mexico Autopista and of Pueblo Nuevo,
of the 4.5
20°06'35"N, 101°4E05"W, 1800 m, 19 Jun 2001, W. Steinmann 1681
ca. V.
DAV! MICH!
ARIZ!
WIS!).
(holotype: IEB!;isotypes: Fig. 1.
m
Frutex 2-5 monoecius, trichomatibus atris clispcrsis vest us; folia alterna,
altus,
it
mm
cm
1-3 stellato-tomentosi, lami-
stipulae subulatae, 2.6-6.5 longae, petioli longi,
cm cm
nae plerumque ovatae, 2.5-9 longae, 1.8-6 latae, bicolores, apice acutae vel
acuminatae, basi rotundatae vel leviter cordatae, supra stellato-puberulae, subtus stel-
lato-tomentosae, margine serrulato-denticulato; infiorescentiae terminales, floribus
(4-) 6-9, staminatis usque ad ca. 60, bracteae subulatae vel lineares, 1.2-3.1
pistillatis
mm
mm
longae, stellato-tomentulosae; florum staminatorum calyx lobis 2.2-2.8
5,
mm
mm
stamina
anguste 3.1-3.6 longa,
1.3-1.9 petala albida, elliptica,
longis,
latis,
mm
antherae 1.0-1.2
15 vel 16, filamenta filiformia 3.0-3.6 longa, villosa, ellipticae,
mm
longae; florum pistillatorum calyx lobis 5 aequalibus, ovatis vel oblongis,
(6),
mm
mm
ovarium stellato-tomentosum,
3.9-5.2 2.8-3.6 trilobatum, styli
longis,
latis,
mm
mm
3.2-3.9 capsula depresso-subglobosa, ca. 6.5
bis bipartati, longi, filiformes;
3,
mm
mm
mm
complanata,
longa 8 semina oblonga, 5.2-5.7 longa, 3.8^1.2 lata,
et lata;
mm mm
caruncula 0.8-1.0 longa, 1.6-2.1
nitida, lata.
m
Shrubs, sometimes aborescent, 2-5 highly branched, drought-deciduous,
tall,
when
monoecious; stems stellate-tomentose young, often with a dingy-yellow cast,
throughout whole bark reddish brown. Leaves
with scattered black hairs the plant,
mm
well-spaced on the stem; stipules 2.6-6.5 long, subulate, pilose to
alternate,
cm
cm
tomentulose; petioles 1-3 long, stellate-tomentose, lacking glands; blades 2.5-9
cm
membranaceous, unlobed, pinnately veined, usually ovate, rarely
1.8-6 wide,
long,
rounded
or oblong, apex acute to acuminate, base to slightly cordate, distinctly
elliptic
white
green, abaxially stellate-tomentose, to
bicolored, adaxially stellate-puberulent,
dingy yellow, margin serrulate-denticulate, sometimes irregularly so and appearing
cm
6-9
erose. Inflorescence a terminal racemelike thyrse to 11 long with (4-) pistil-
late flowers towards the base and up to ca. 60 staminate flowers along the proximal
portion, flowers sometimes abortive and the inflorescence then appearing
pistillate
mm
bracteoles
unisexual, bracts 1.2-3.1 long, subulate to linear, stellate-tomentulose,
w
usm
or mirharii
Miciiii,
ivi
/
flow
Pishllah-
I
. .
...
mm
0.4-1.1 Stami
long, filiform, pilose. slender,
stellate-i
i
mm
mm mm
pedicels 2.2-3. long; calyx 5-partite. lohes 2.2 2.8 long, .3-1.9 wide,
tri-
1 1
angular-ovate to broadly ellip [ua to nearly the base, apex bluntly pointed,
re<
tii
mm
on
stellate-tomentose the outside, glabrous within: petals 1-3.6 long, 0.7-0.9
5. 3.
mm
wide, narrowly elliptic, whitish, free to the base, apex rounded, glabrous on the
mm
outside, villosc within and along the margin; stamens IS or filaments 3.0-3.6
16.
mm
and
long, filiform flexuous, villous especially towards the base, anthers 1.0-1.2
mm
nun
owl on
,( ' n IIipiK n! stout pedicels 1 long
ii il
I I
i i
(U
or calyx valvate-reduplieai wilh adjacent Kate forming
less; pairs ol a sepals a
\
.
—
EUPHORBIACEAE
STEINMANN:
2005 175
projection at the base), sepals 5 united ca. 1/4 to 1/3 their length, the lobes ovate
(6)
mm
oblong, somewhat accrescent and enlarging to 3.9-5.2 long, 2.8-3.6
to in fruit
mm
wide, apex rounded, stellate-tomentose on the outside and along the inner edges,
mm
sometimes
inner surface otherwise glabrous; petals present, to 4.3 long, strap-
mm
ovary 3-lobed, stellate-tomentose, styles filiform, 3.2-3.9 long, twice bifid,
like; 3,
mm mm
numerous Capsule
rusty-brown, with stellate trichomes. ca. 6.5 long, ca. 8 in
had begun depressed-globose;
diameter (estimates only; fruits already to dehisce),
mm mm mm
columella 5-5.5 long. Seeds 5.2-5.7 long, 3.8^.2 wide, oblong in dorsal
view, dorsal-ventrally flattened, rounded at the base, rounded and with a minute
nipplelike projection at the apex, microscopically rugulose, shiny; caruncle 0.8-1.0
mm mm
and
long, 1.6-2.1 wide, tan thin.
The epithet to the black stellate trichomes that are scattered
atr, s
am Mexican
throughout the plant. unaware of this feature in any other species of
I
Croton, and occurrence serves to separate this taxon from all others in western
its
Mexico. Some areas of the plant actually appear to the naked eye to be infested by
a rust, but in fact a proliferation of these black trichomes that causes this illu-
it is
Webster presence
sion. According to the infrageneric circumscription of (1993), the
and and
of valvate-reduplicate pistillate sepals, eglandular stipules sepals, a stellate
Lasiogyne
pubescence warrants the placement of Croton atrostellatus in section
No known
members from western
(Klotzsch) Baill. other of this section are tropical
Mexico by Webster
Mexico (Webster and the only representative given for in
2001),
Apart from
1993 conspectus C. tabascensis Lundell. lacking the characteristic
his
is
young
black trichomes, tabascensis differs in having hispid stems, leaves that are
C.
and
not bicolored and only moderately stellate-pubescent beneath, sepals that are
uniformly pubescent on the inner surface. Also, although supposedly not charac-
of the section Lasiogyne, in C. tabascensis the sepals of the pistillate flowers
teristic
known
from only two
collections
possess small, sessile glands. latus is
(
< i
Michoacan
the subtropical scrub of the Bajio region in northwestern at elevations
in
from 1800 1900 m. At the type locality grows sympatrically with C. adspersus
to
it
was June and with
Benth. and sphaerocarpus H. B. K. collected with flowers in
C. It
October.
fruits in
Mexico. Michoacan: Mpio.
Euphorbia W. Steinmann, Type:
calderoniae nov.
V. sp.
Dec
2500 m,
Cuanajo, Cerro del Burro, pastizal, ladera de cerro, potrero, 3
MICH!).
M. Escobedo 756 (holotype: IEB!;isotype:
1985,/.
cm
Herba annua, prostrata; caules usque ad 20 longi, supra pilosi vel puberuli,
mm
laminae obovatae
infra glabri, teretes; folia opposita, petioli 0.3-0.5 longi, vel
cm cm
oblongae, 0.3-0.6 longae, 0.2-0.4 latae, basi asymmetricae, rotundatae vel
margo pedun-
hemicordatae, apice obtusae, integer vel serrulatus; cyathia solitaria,
mm
mm
involucra infundibularia vel fere cylindrica, 0.7-0.9
0.3-1.2 longi, glabri;
culi
mm
longa, 0.6-0.7 interne pubescentia, glandulae circulares vel ovales, ca.
lata, 4,
mm
mm
longae appendices ut videtur absentes vel angustae, 0.1 longae,
et latae,
0.1
mm
ovarium subglobosum ovoideum,
Mores staminati 5-8; trilobatum, vel
0.2 latae,
mm
subglobosa
glabrum, 0.3-0.4 longi, bipartiti; capsula trilobata, vel
styli 3, liberi,
mm
mm mm
semina ovoidea, 0.8-0.9
ovoidea, 1 .3-1 .4 longa, 1 .5-1 .6 lata; triangula,
mm
longa, 0.6-0.7
lata.
i
CONTR. UNIVERSITY OF MICHIGAN HERBARIUM VOLUME
176
24
Prostrate annual from a slender, brown, vertical laprool; stems lew to many
aris-
em
ing from near the base, to 20 long, generally mat forming and extending
radially,
diffuse to compact, moderate!) to highly branched, mternodes 0.5-2 cm
long, terete,
pilose to strigulost o puberi enl pubescent only on the exposed surfaces, glabrous
on
the portions fad the lund hail crisped ed or rarely almost straight,
t< \
i i
j
mm
0.1-0.4 long, while to purple-tinged. Leaves opposite: stipules of parts of the
all
mm
stems
similar, 0.2-0.5 long, divide divisions or represented by a
n
i
i
mm
margined
small, triangular laciniately scale: petioles 0.3-0.5 long, glabrous or
mm
sparsely pilose with spreading white hairs to 0.7 long; blades 0.3-0.6 cm
long,
cm
0.2-0.4 wide, obovate to oblong, with a prominent mitlvein but the lateral veins
inconspicuous, glabrous to sparsely pilose, base asymmetrical, rounded
to slightly
hemicordate, apex rounded maturity although when
frequently acute young,
al
margin
towards
serrulate at least the tip but usually entire along the distal 1/2-1/3.
mm
Cyathia
solitary in the distal nodes, peduncles 0.3-1.2 long, glabrous. Involucre
mm mm
0.7-0.9 long, 0.6 0.7 wide below the glands, mlundibuliform nearly
to cylin-
drical, outer surface glabrous, inner surface pilose below the rim; lobes subulate,
mm
sometimes
0.1-0.3 long, divided, sinus shallow glands
a us; 4, ca. 0.1
•
i
mm
long and appendages
wide, circular to oval, absent or represented by narrow
a
mm
mm
rim long and wavy
ca. 0.1 0.2 wide, glabrous, entire to or bilobed, white to
Slaminak
reddish
flowers m.Ci
l.racii U n glabrous, exserted
,U >h
v>
, >|
I
mm
mm,
0.9-1.7 ovary 3 lobed. subglobose to ovoid, glabrous, styles free, 0.3-0.4
3,
mm
long, biparted to nearly the base, divisions Capsule
filiform. 1.3-1.4 long, 1.5-1.6
mm
mm
in diameter, strongk 3-lo d u e to broadly ovoid, columella 0.9-1.0
h<
>s
!
mm mm
Seeds
long. 0.8-0.9 long, 0.6 0.7 wide, tnangulai cross section, the ventral
in
faces collectively forming a single face, ovoid in dorsal view, blackish to blackish gray,
apex
micropapilliate, bluntly pointed, base rounded, dorsal keel prominent, blunt,
mm
uninterrupted, dorsal faces mostly plane. 0.6 smooth; caruncle absent.
all.
hi
si,
j,-, I],
i i i i i i - i, - , i i / ,
km
(IEB); Mpio.Zinapoouaio.5 SSI do .lorahuam. R~nl mski Mpio. Uruapan,5 km
al /6/-/.MII U S
al
1 ( ):
do Angahuan. on ol Jano ( 'hoi niro. Soto Niinez /.W,S'2 (MEXU).
I
The
specific epii! in baeiela Calderdn de Rzedowski,
(
i
a researcher at the Institute de Ecologia-Centro Regional del Bajfo and
specialist
Mexican
of plants. She is coeditor of the f-'lora del Bajfo y de Regiones Adyacentes,
and one known,
but of the nlkr! ><<,,>
all ni, .tL-leromae occur within the
>q
i
boundaries
of this Floi<i It ubg Chamaesyce,
,
many
and
like so other speei !, ul en us, he seeds ser\e to distinguish In
-i it.
I
habit resembles a prostrate and diminutive form of l-jtpliorhia nutans Lag. and
it
apparently is related to this species: however, from this and close allies separated
it is
by the possession of seeds with plane and smooth
dorsal faces. In related species the
convex and
dorsal faces are variously sculptured. In addition, the ventral two faces
of E. calderoniae form a single flat surface, whereas in related species the ventral
two
form convex
faces usually a surface. The leaves of ea/deroniae are reminiscent
E.
m
of those of both shape and
E. serpyllifolia Pers. in being mostly entire along the
proximal margin and only serrulate towards the apex; addition seed
in to characters,
the pubescent stems readily serve to distinguish E. calderoniae from this species. The
known m
four localities of E. calderoniae aio
h< >n n<
tli
> <
i i
i
Michoacan, where
found grasslands, humid canyons pine-oak and
it is in in forest,
scrub vegetation at elevations from 2300 to 2500 m. lowering and fruiting overlap
I
broadly, and lerlile material has been collected August and December.
in
—
EUPHORBIACEAE
177
Euphorbia W. Steinmann, Type: Mexico. Michoacan:
infernidialis V. nov.
sp.
MEX
N
km
Mpio. La Huacana, along of Los Ranchos, 18°44'N,
37, ca.
1
&
o May
101 00'45" W, ± 200 m, 9 2002, V. W. Steinmann, G. Puime B. Vrskovy
2458
(holotype:IEB!).
Fig.
2.
cm
Herba perennis, prostrata vel ascendens; caules usque ad 25 longi, pilosi,
mm
teretes; folia opposita, petioli 0.3-0.8 longi, laminae variabiles, plerumque oblon-
cm
cm
gae, 0.3-0.5 longae, 0.25-0.35 latae, basi asymmetricae et hemicordatae, apice
mm
margo
pedunculi
obtusae, integer vel leviter serrulatus; cyathia solitaria, 1.8-3.3
mm mm
involucra campanulata, .2-1 longa, 1.1-1.6 pilosa, glandulae
longi; lata,
.7 4,
1
mm mm
ovales, 0.2-0.4 longae (radialiter), 0.4-0.7 latae (tangentialiter), appendices
mm mm
semicirculares vel flabellatae, 0.4-0.7 longae, 0.7-1.1 latae; flores staminati ca.
25-35; ovarium trilobatum, ovoideum, versus basim et secus carinas pilosum, styli
3,
mm mm
0.3-0.4 capsula ovoidea, 1.5-1.9 longa, 1.4-1.8
liberi, longi, bipartiti; trilobata,
mm
lata, versus basim et secus carinas pilosa; semina quadrangula, elliptico-ovoidea,
mm mm
1.1-1.6 longa, 0.6-0.8
lata.
woody
Prostrate to ascending perennial herb from a brown, thickened, and tap
cm
root; stems numerous arising from near the base, to 25 long, internodes to 1.5
cm
long, terete, uniformly pubescent around the entire circumference; stems, leaves,
peduncles, and involucres shortly pilose with to slightly curved white hairs 0.1-0.2
stiff
mm
exposed
(-0.3) long. Leaves opposite; stipules dimorphic, those of the surfaces of
the stem remarkably reduced, inconspicuous, narrowly triangular to subulate, 0.1-0.2
mm
long or apparently absent, those facing the ground mostly united into a broadly
mm mm
triangular scale 0.3-0.5 long with a laciniate-erose margin; petioles 0.3-0.8
cm cm
long; blades 0.3-0.5 long, 0.25-0.35 wide, generally oblong but varying to ovate,
obovate base asymmetrical and hemicordate, apex rounded, margin
or orbicular,
mm
entire to faintly serrulate. Cyathia solitary at the distal nodes, peduncles 1.8-3.3
mm mm
wide below campanulate,
long. Involucre 1.2-1.7 long, 1.1-1.6 the glands,
mm
U-
inner and outer surfaces pilose, lobes ca. 0.2 long, triangular, sinus shallowly
mm mm
shaped, extending ca. 1/5 the involucre, glands 0.2-0.4 long (radially), 0.4-0.7
mm mm
wide (tangentially), oval, appendages 0.4-0.7 long, 0.7-1.1 wide, semicircular
glabrous or puberulent on the back, entire to shallowly wavy, white
to flabellate,
fading pink. Staminate flowers 25-35, bracteoles numerous, divided and pilose
ca.
mm,
Gynophore
towards the glabrous, exserted 1.3-3.2 ovary conspicuously 3-
tip.
with concentrated towards the base and along the
lobed, ovoid, pilose hairs
stiffly
mm
from
keels; styles free, 0.3-0.4 long, biparted 2/3 their length to nearly the base,
3,
mm mm
divisions clavate. Capsule 1.5-1.9 long, 1.4-1.8 in diameter, strongly 3-lobed,
ovoid, broadest towards the base, pilose with straight, white, erect hairs 0.1-0.2
stiffly
mm mm
long, these concentrated towards the base and along the keels. Seeds 1.1-1.6
mm
long, 0.6-0.8 wide, quadrangular in cross section, row v ptic-ovoid in dorsal
n;.* ,11
view, base obliquely truncate, apex pointed, reddish-brown, with a prominent dorsal
mm
sometime low
keel, dorsal faces 0.5-0.7 lightly rippled, with a but conspicu-
tall,
ous longitudinal ridge, nearly plane to slightly convex, ecarunculate.
The Michoacan and
specific epithet refers to the Infiernillo region of southern
man-made
around
Guerrero. This area centered the Presa Infiernillo, a reservoir
is
damming
resulting from the of the Rio Balsas just downstream from confluence with
its
CONTl m itm <H\ Ml
in.,
l\ 111 '!
II
I I • i r « [ ,
dissected, xtO.E. Seed,
2 >
the Rio Tepalcatepec. The only known collections were made few kilometers
just a
wah
from body
inland of belongs Chamaesyce.
this in inj udiali to subg.
* i>> !• >, / ->
The
presence of ovaries with hairs restricted to the base and along the keels suggests
a relationship with E. U u< with K h S .art Boiss. and E. mendezii Boiss.,
•.<
l« <
< \ i I , »
and both
of these species occur in the vicinity. Yet, these species possess strongly dor-
siventrally flattened stems with long spreading hairs along the margin, larger
stipules,
and cyathia dense and congested primary
in lateral e stems. In contrast,
sh< oJ
»ot:
has stems without educed
injerniriialis terete hi- spi. i«<m h; n stipules,
/:. iil\
- I. « i
—
-
I
STEINMANN:EUPHORBIACEAE
2005 179
and cyathia borne solitary at the distal nodes of the primary stems. Oddly enough,
made
the type collection was from plants growing in the disturbed roadside directly
known made
was
adjacent to the highway and the only other collection along the
side of a dirt road. The adjacent vegetation in both of these areas is arid thorn forest.
The only two collections were encountered in full flower during the height of the dry
members Chamaesyce
season (March to May), a time during which most of subg. are
summer
dormant. has been observed flower during the rainy season.
also to
It
Euphorbia W. Steinmann, Type: Mexico. Michoacan: Mpio.
lottiae V. sp. nov.
MEX
km
SSE
Arteaga, 30.5 (by road) of the junction with 37 along the road
18°21'58"N, 101°54'09"W, 300 m, 19 Oct 1996, W. Stein-
to Infiernillo, ca. V.
MEXU!
& ARIZ! MICH!
mann
L. Varela E. 1104 (holotype: IEB!; isotypes:
NY!UCR!).
Fig. 3.
Herba annua ephemera, prostrata vel decumbens; Euphorbiae barnesii affinis, a
pedun-
qua basi subpeltatis, ramulis junioribus canaliculars, pedunculis villosis,
foliis
longioribus
culis et stylis differt.
decumbent and hydro
ephemeral, almost turgescent rather
Delicate, prostrate to
phytic in character, from a slender taproot; stems numerous, prolincally sprawling,
45 cm glabrous, the young ones upon drying usually caniculate with several
to long,
on
sharp, whitish to translucent longitudinal ridges. Leaves alternate, well spaced the
inconspicuous and represented by minute, glanduliform protuberances
stem; stipules
mm
cm
0.1 long; petioles 0.6-2.7 long, slender, usually longer than the blade, glabrous
mm
and
or sparsely villous with slender, wavy, white hairs 0.4-1.2 long; blade thin
cm cm
membranaceous, that of the larger leaves 0.9-1.7 long, 0.8-1.8 wide, broadly
ovate to sometimes orbicular, leaves near the branch tips with the blade smaller and
generally ovate to glabrate above, sparsely villous below with hairs like those
elliptic,
of the petiole, rounded or bluntly pointed at the apex, continuous over the adaxial
margin
side of the petiole and thus appearing minutely subpeltate at the base, entire.
on open and
Cyathia the nodes the ends of the stems or loose axil-
solitary at at distal
mm
branches; peduncle 2-9 long, slender to capillary, villous at least towards the
lary
mm mm
wide below campanulate
base. Involucre 0.9-1.1 long, 0.7-1.1 the glands, to
infundibuliform, sparsely villous on the outer surface, shortly pilose towards the rim
mm
on oblong obovate, fimbriate the
the inner surface, lobes ca. 0.2 long, to slightly at
mm mm
wide narrowly
apex; glands 0.1-0.15 long (radially), 0.3-0.4 (tangentially),
5,
oblong to reniform, light yellow becoming pinkish in age, appendages divided into
mm
4-6 segments green Staminate flowers 20-25,
filiform 0.3-0.6 long, to whitish. ca.
bracteoles few, plumose towards the Gynophore slender to capillary, extending
tips.
mm
to 4 long, glabrous, ovary subglobose to oblong, 3-lobed, glabrous; styles 3, 0.5-0.7
mm
mm
long, free, biparted to the base, divisions filiform. Capsule 3-lobed, 1.0-1.3
mm
mm
long, 1.2-1.4 in diameter, subglobose to ovoid or oblong, columella 1.0-1.2
mm mm
rounded ovoid
long. Seeds 0.9-1.1 long, 0.6-0.7 in diameter, in cross section,
gray with numerous coarse tubercles interspersed with
in dorsal view, light to tan,
bottoms
several mostly regular longitudinal rows of isodiametric depressions the of
which contain a punctiform ecarunculate.
pit,
Additional Specimens Examined. Mexico. Ialisco ilong h» id I'roi Sn do los Corrales, Mpio.
i , i i
HW
(IEB FnUlcma 2230A (MICH); Mpio.
can./ DC
illan Icaic, Iich tcrl "'1
1).
|
NW
km (ENCB,
Tecalitlan, cerca de Gallardo, 10 de Tepalcatepcc. Michoacan. Rzcdowski 17497
al
Mm
WSW
M
CH).— an: 11-13 km of Apatzingan, along the road to Dos Aguas and Aguililla, Dieterle
«
)A(
IUm
A km Aik-am-Nii
-.'.y;,--' !'./;« II), ;,,„» \Mlm«.i 'Hm.ilN.I. Inheiiiillo. al S dc la in I oil ei
f <. • i
i
CONTR. UNIVERSITY MK
,A\ IKK
\<)Kl Ml-
'! i,\l< \i
( >l- l< II ' :
! f I
FIG. Euphorbia
3. I
duliform stipules (with
1<
dissected, xlO.F. Seed,
d(
This species dedicated Emily Euphorbiaceae and
id Lott, enthusiast
is a
J.
leading authority on the pKii ropical d forest of western Mexico.
li
i
She
collected the species at the type locality in I9.S3. Euphorbia lottiae belongs to
Agaloma member
and ocymoulea McVaugh
subg. is a of the L. complex. (1993)
/:.
provided a general overview ol this group, recognizing three varieties of Euphorbia
ocymoideaw&x.hi McVaugh,
ocxmoidetL and
var. var. subreniformis
il
, )
Watson) McVaugh. McVaugh
(S. agree with concerning the taxa recognized as well
I
STEINMANN: EUPHORBIACEAE
2005
181
as the characters used to distinguish them; however, differ with him in the belief
I
opposed
that they are best treated as distinct species as to infraspecific taxa. These,
together with Euphorbia probably form a monophyletic group and are indeed
lottiae,
somewhat them
very similar, so their rank arbitrary. prefer to recognize as species
is I
more
for various reasons. All are morphologically distinct from each other by than a
There and
single character. are ecological differences as well, with E. lottiae E. ocy-
moidea growing low Watson
at elevations in tropical vegetation, E. subreniformis
S.
occurring at higher elevations in mostly pine-oak forest, and E. bamesii (Millsp.)
Oudejans occurring in both such habitats. Furthermore, their ranges are independent,
and they maintain their distinctiveness even when growing in the same general area.
McVaugh's Euphorbia would come and some
In 1993 key. out to E. bamesii,
lottiae
specimens were initially identified as such. Although these two share consistently
and
5-glanded involucres, glabrous ovaries capsules, slender to capillary gynophores,
and number The
eglandular branchlets, they differ in a of features. following couplet
serves to distinguish them.
Young
stems drying terete; long spreading hairs restricted to the outer surface of the involucre;
1.
base of the leaf blade attached to the adaxial side of the petiole and not continuous over
it;
mm
peduncles 0.5-1 (-! long nous; styles 0.3-0.4 long. E. bamesii
5) <J
il
Jm
Young stems, upon drying, umi< u hi Imnslu ni longitu
1. villi s t\>
II il \^
I -
ii.ii! ding hairs sometimes present on the stems and leaves in addition to the
i.
-
| i
involucres; base of the leaf blade continuous over the adaxial side of the petiole and thus appear-
mm
ing minutely subpeltate; peduncles 2-9 long, villous at least towards the base: styles 0.5-0.7
Euphorbia lottiae also appears to differ from the other species of the complex
by habit. almost turgescent and rather hydrophytic in character, whereas
its It is its
more As
close relatives possess wiry and fibrous stems. far as can the branches
I tell,
of the others are mostly erect to ascending. In contrast, the branches of E. lottiae are
weak, primarily prostrate to decumbent, and prolifically sprawling. This species
is
known number
from a small of collections gathered at four localities in the valley of
the Rio Tepalcatepec in southern Michoacan and adjacent Jalisco, where occurs in
it
thorn forest and tropical deciduous forest at elevations ranging from 300 to 500 m.
It
from
grows Guerrero; the type only about 3 kilometers the
likely also in locality
is
border and with vegetation similar to that of vast expanses in adjacent Guerrero.
It
one and
thrives during the brief rainy season, but of the plants to wilt die as
first
is
known made
the rains diminish and the soil dries. All collections were from early
September October.
to late
nov.—
Jatropha jaimejimenezii W. Steinmann, Type: Mexico. Michoacan: Mpio.
V.
sp.
MEX
N
km km
Arteaga, along 75 (by road) of Arteaga and S of
37, ca. 1
El Descansadero, 18°38'41 "N, 101°58'10"W, ± 300 m, shallow ravine on the
rocky hillside above the highway, open thorn forest with columnar cacti, 3
&
Aug
2001, W. Steinmann E Carranza E. Perez 1810 (holotype: IEB!;
V.
ARIZ! MICH!
DAV!).
isotypes: Fig.
4.
m
Frutex usque ad 2 (-3) altus, monoecius; folia alterna, stipulae in lacinias
mm
cm
laminae
glanduligeras dissectae, 1-2.5 longae, petioli 0.3-1.2 (-1.5) longi,
cm cm
plerumque
oblongae, 1.0-3.8 longae, 0.8-3.6
variabiles, (0.7-) (0.6-) latae,
margo
apice obtusae, basi obtusae vel truncatae, glanduloso-denticulatus; inflores-
cm
centiae cymosae, dichasiales, 1.5-4.5 longae, bracteae ellipticae vel spathulatae,
mm mm
margo
2-9 florum
longae, 0.5-2.5 latae, pilosae, glanduloso-denticulatus;
CONTR. UNIVERSITY OF MICHIGAN HERBARIUM VOLUME
182 24
mm
staminatorum
pedicelli graciles, 3.2-5.5 longi, pilosi, calyx imbricatus, lobi
5,
mm mm
13
ovati, oblongi vel 3.2-5.5 longi. 03) corolla imbricata,
elliptici, liberi,
lati,
mm mm
lobi spathulati vel oblongi, basi connati, 5.4-6.2 longi, 1.7-2.2 apice
5, lati,
mm
columnam
reflexi, stamina in connata 3.8-5.2 longa, antherae oblongae, 1.1-1.4
5,
mm
mm
longae; florum pistillatorum pedicelli 1.8 -3.5 longi, villoso-pilosi, calyx
mm
plerumque
imbricatus, lobi obovati vel spathulati, accrescentes, 6.5-11.8 longi,
5,
mm mm mm
2.6-5.4 corolla imbricata, lobi 5 ovati, 5.3-6.0 longi, 2.0-2.5
lati, (6), lati,
apice reflexi, ovarium triloculatum, oblongo-ovoideum, basi planum, glabrum,
styli
3,
mm
cm cm
filiformes, 3.1-4.3 longi; capsula oblongo-ovoidea, 0.9-1.2 longa, 0.7-0.8
mm mm
lata, trilobata; semina oblonga, 6.5-7.3 longa, 3.9-4.4 lata, laevia, caruncula
mm mm
cucullilormis, longa, 2.7-3.2
1.4 1.9 lata.
m
Shrubs to 2 (-3) multibranched from near the base and highly branched
tall,
above, drought-deciduous, with copious reddish monoecious; stems
the
latex, villous,
mm
hairs nearly straight, 1.1-2.2 long, multicellular, white and sometimes purplish
at the base, lower layer of shorter appressed to recurved hairs also present, branches
soft-wooded and iH«»r.dhd and
aliened exfo-
bl<
i>
II- ( il
I < I i
liating in thin slivers. Leaves alternate, mostly congested on short, arrested shoots;
mm
represented by mul im
stipules irregularly tinctures 1-2.5
hi< mi,
I , i
i
cm
long; petiole 0.3-1.2 (-1.5) long, with pubescence like that of the stem; blade
cm cm
membranaceous,
(0.7-) .0-3.8 long, (0.6-) 0.8-3.6 wide, with basal attachment
1
to the petiole, mostly oblong but varying > elliptic, rarely rotund or shal-
fr< tt<
>
i
lowly palmately 3-lobed, palmately 3-veined from the base with the midvein more
prominent
than the laterals, apex obtuse, base truncate to obtuse, hirsute to villous
on both surfaces, margin in uleb denl cul clh ending stipitale glands
ith U in
it it -
mm
om
0.1-0.2 long, in age the gland tim( shed and the margin appearing entire.
cm
Inflorescences many-flowerei .5-4.5 long, entirely staminate or
les
lie!
i 1
with pistillate flowers at the lower first and second nodes, pistillate flowers also some-
times solitary on the short shoots, axis with pubescence as on the stem but the hairs
mm mm
cm
tending to be shorter, peduncle 0.4-2 long, bracts 2-9 long, 0.5-2,5 wide,
narrowly elliptic to spathulate, thinlv pilose, the margin as the leaves. Staminate
in
mm
on
flowers slendei pilose pedicels 5.5 loi
5
I :
mm
m
3.2-5.5 long, 0.9 2.3 iwidi o ilon 4\ unequal, free to
il
« I li I
|
the base, apex mostly obtuse, rarely acute, pilose to puberulent on the outside, mostly
glabrous within, rarely filiate with stipitate glands oroibi imbricate, lobes
,v
•
mm mm
5,5.4-6.2 long, 1.7-2.2 wide, broadly spathulate to oblong, united 1/5 to 1/4
their length, apex obtuse, glabrous to minutely puberulent, often puberulent-ciliate,
red-pink, free portion strongly overlapping and appearing united towards the base
mm
but clearly separate above, tips rcflexcd at anlhesis: disk glands 5.0.6-1.1 long,
mm
separate, ± oblong, dark brown; stamens 5. united into a column 3.8 5.2 long, free
mm
mm,
for 0.3-0.8 anthers 1-1 long, narrowly oblong, sometimes with
.4 a filiform
1
.
mm
1mm
appendage
0.5-1.7 long, m.» het\ n mttius, outer whorl of stamens
ill.
i
mm
on
absent. (lowers
Pistillate relatively stout, villous-pilose pedicels 1.8-3.5 long;
calyx imbricate, lobes strongly unequal, generally obovate
5. to spathulate, rarely
mm mm
oblong or ovate, accrescent in fruit and expanding to 6.5-1 long, 2.6-5.4
.8
1
wide, apex obtuse or acute, thinly pilose on both surfaces, stipilate-glandular along
mm
mm
the margin; corolla strongly imbricate, lobes 5 5.3 6.0 long, 2.0-2.5 wide.
(6),
ovate, united only at the extreme base, apex obtuse, thinly pilose on both surfaces,
ud pn ,md
'nl ni ! ais lalhng as a
»il< iii il.
i,
i i i i . I i i i
single unit, disk annular, undulate and shallowly lobed; ovary 3-locular. oblong-ovoid
mm
with a fiat base, inconspicuously 3-angled, glabrous, styles 1—1.3 long, filiform.
3, 3.
