CRATAEGUS NANANIXONII (ROSACEAE, SER. INTRICATAE) A NEW SPECIES OF HAWTHORN FROM EASTERN TEXAS

6 Pages·1997·3.2 MB·English

by  J B Phipps

CRATAEGUS NANANIXONII
(ROSACEAE,
NEW
A OF
INTRICATAE) SPECIES
SER.
HAWTHORN
FROM
EASTERN TEXAS
The
University Western Ontario
of
Department Plant
of Sciences
CANADA
N6A
3B7
London, Ontario,
O'KENNON
R.J.
Botanical Research Institute of Texas
509
Pecan
Street
TX
76102-4060,
Fort Worth, U.S.A.
Nacogdoches.
In preparation for the forthcoming Flora of Texas, this paper describes a
known number
new species of Crataegus which has been for a of years from
sand plains near Nacogdoches, Texas. This species cannot be matched with
m
anything of Texas plants Hatch 1990, Johnston 1990,
lists (e.g. et al.
Mahler 1988, Nixon 1985, Simpson 1988, Vines 1977) or Louisiana
Manual
(MacRoberts 1988). In Correll and Johnston's (1970) the Vascu-
of
down
would key unambiguously Muenchh.,
lar Plants Texas to C. unifiora
of it
the ripe fruit color were known. However, very different from that
if it is
discussed below.
species, as
&
Crataegus nananixonii Phipps O'Kennon,
J.B. R.J. sp. nov. (Fig. 1).
N
Type: TEXAS: Nacogdoches Co.: mi of of FM1087 and Co. Rd. 153, on
jet.
1
UWO).
Co. Rd. 153, 14 Apr 1989, ^.S. Nixon 7430 (hoi.otype: ASTC; lsotype:
J

1
A
Phipps and O'Kennon, new species of Crataegus from Eastern Texas 37
longi, glanduloso-maculati. Inflorescentiae 3-5 florae; pedicellis patento-pubescentibus,
bracteolis caducis linearis glandulo-marginibus conspicuis in anthesem praecocem; anthe-
mm mm
Aprili. Flores 12-15 diam.; hypanthium glabrum; lobi calycis 4-5 longi,
sis in
minusve stamina
glandulo-marginati, glabri adaxiale; petala ± orbiculares, plus unguiculata;
1-4
ca. 10, antheris rose-purpureis; carpelli et styla 5. Infructescentiae fructae, pedicellis
m
cm
Shrub, 1-2.5 quite intricately branched; thorns 1-3 long,
tall,
straight to slightly recurved, dark dull grey. Leaves deciduous, peti-
fine,
cm
olate; leaf-blades 1.5-3.5 long, rhomb-ovate, extremely shallowly lobed
somewhat
or unlobed, margins irregularly serrate, thinly scabrous-hairy
when
adaxially young, glabrous abaxially, at maturity almost entirely gla-
brous except for some pubescence on the veins abaxially, and with gland-
dots in some of the teeth especially proximally, with about 3 pairs of sec-
mm
5-15 3-5
ondary veins; petioles long, gland-dotted. Inflorescence
flowered, branches with spreading pubescence, caducous linear gland-mar-
12-
gined bracteoles conspicuous in early anthesis; anthesis April. Flowers
mm
mm
4-5
hypanthium gland-mar-
diam; glabrous; calyx lobes long,
5
1
with stamens about
gined, glabrous abaxially; petals ± orbicular slight claw;
1-
10, anthers rose-purple in color; carpels and styles 3-5. Infructescences
cm
4 pedicels with thin spreading pubescence. Fruits diameter,
fruited;
1
when
remnants
± orbicular, coppery red ripe, glabrous, calyx present or
not on a slightly elevated rim; pyrenes 3-5.
N EM
Additional specimens examined: TEXAS: Nacogdoches Co.: ca mi of of
jet.
1
34(UWO);ca. ImiNofjct.of
Apr
14 9H9, E.S.Nixon 173
lie,
1
m
cut area, occasional, 1.8 tall,
ImiNof
o«/7336(UWO);ca.
[Apr C.5.N.X
1989,
TTi7
on
It
Imi
N;xo«i7339(UWO);ca.
Apr
rose-purpl 14 1989,
E.S.
rs
e,'
m
;o.Rd. 153( 15 regenerating on a clearcut area, occasional, 2
3,
l4Aprl989,i fUWO);ca.l
N/xo« 7340
hers rose-pu rple, 5.5.
7
^Co.Rd. 3onl53,regenerari ng on
15 a clearcut area, occasional,
l4Aprl989, (UWO);
Nixon 7342
ithers rose-p urple, E.S. ca,
1 1
kCo.Rd. 15 ng on a clearcut area, occasional,
(UWO);
anthers rose -purple,' i4 Apr 198' E.S. Nixon 1 7343 ca.
9,
N
EM &
mi of of 1087 Co. Rd. 153 on 153, regenerating on a clearcut area, occa
ict.
1
m
sionai, 1.2 white flowers, anthers rose-purple, 14 Apr 1989, E.S. Nixon 1734-
tall,
W
EM &
(UWO); mi of of 1087 Co. Rd. 153 on 1087, dry upland, post oak
1.3 jet.
W
EM &
(UWO);
Nixon 17321 mi of of 1087 Co. Rd. 153 on 1087, dr
1.3
E.S. jet.
W
EM
&
(UWO); Rd
purple, 19 Apr 1989, E.S. Nixon 17322 1.3 mi of jet. of 1087 Co.
W
(UWO);
Apr Nixon 17323 mi of of FA
ers, anthers rose-purple, 19 1989, E.S. 1.3 jet.
& &
1087 Co. Rd. 153 on 1087, dry upland, post oak, shortleaf pine sandjack oak, 2.4 n
tall, white flowers, anthers rose-purple, 19 Apr 1989, E.S. Nixon 17324 (UWO); 1.3 mi
W
ofFM & &
of 1087 Co. Rd. 153 on 1087, dry upland, post oak, shortleaf pine sand-
jet.
m
jack oak, 2.1 white flowers, anthers rose-purple, 19 Apr 1989, Nixon 17325
tall, E.S.
W
FM &
(UWO); 1.3 mi of jet. of 1087 Co. Rd. 5 S on ()S7, dry upland, post oak, short-
1 1
m
&
leaf pine sand jack oak, 2.1 tall, white flowers, .mthers rose-purple, 9 Apr 989, £.^.
1 1
W
FM
Apr Nixon 17327 (UWO); mi 108"
1989, E.S. 1.3 of of Co. Rd. 153 on
jet. c^
& m
1087, dry upland, post oak, shortleaf pine sandjack oak, 2.3 white flowers, anthers
tall,
Apr (UWO);
Nixon 17328
rose-purple, 19 1989, E.S. right-hand side (northwards) of Co.
N
FM
WofGarrison i7W,
Rd. 53, several miles on 1087, just of scout camp, ^1 52'N 94
1
N
Hwy Hwy
fruit, 18 Oct 1988, y.B. Phipps 6277 (UWO); 1087, 3.7 mi E of 250, of
UWO).
Apr
Nacogdoches, sandy 13 1993, O'Kennon 11239 (BRIT,
forest,
R.J.
This distinctive and attractive species restricted to open sandy scru-
is
common
bland of oak, in Nacogdoches Co., Texas, where locally and
it is
we naming
are for Elray Nixon, formerly of Stephen Austin State
it S. F.
who
University, Nacogdoches, provided B. Phipps with a quantity of flower-
J.
ing material and directed him to its site in September 1988. The first part
of the root "nana" recognizes the dwarf stature of the plant.
At namnnxomt Muenchh.
sight, Crataegus resembles of
first C. uniflora
series Parvifoliae (Loud.) Rehder, but this primarily due to small habit,
is its
and and
leaves, flowers, fruits few-flowered inflorescences. Detailed charac-
more
teristics however, are similar to those of series Intricatae (Loud.) Rehder
with which nanamxonii thorny
C. shares a nature, rhomb-elliptic leaf shape,
glandular leaf-bases and petioles, abundant caducous glandular bracteoles
and ruddy with
fruit a small collar. Also, the unspecialised calyx lobe of C.
nananixomt excludes this plant from series Parvifoliae. There however, a
is,
form q{ Crataegus uniflora superficially similar to C. nananixonii with rhom-
more
bic-obtrullate rather than elliptic-obtuse leaves typical of the species
that widely scattered across the southern This has been recorded
is states.
for Texas on sandhills near Tyler in Smith Co. and also has several flowers to
the inflorescence, like C. nananixonii, a feature however, not rare in true C.
umflora.
The
possibility that Crataegus nananixonii was in reality a highly dwarfed
form
of a generally larger species of series Intricatae therefore needed to be
some we
addressed in detail and for this purpose considered those species
members
listed in Vines (I960), i.e. all of the series occurring west of the
Mississippi. Crataegus
intricata, C. neobushii, C. buckleyi, C. rubella, C. padifolia
may
and C. pagensis be rejected immediately on account of their glabrous
and young
inflorescences foliage since this a generally reliable character
is
Among
North American
at the species level in Crataegus taxonomy. the
much
with pubescent and
species inflorescence foliage are too large but
all
a
AND O'Kennon, new
Piiipps species of Crataegus from Eastern Texas 573
Of
some
need to be compared, nevertheless. those with substantive simi-
rose purple or rose-colored in Vines' key) anthers but 20 stamens
('red'
Stamen
while biltmoreana has 10 stamens but cream-colored anthers.
C.
number and two good taxonomic
anther color of course, generally char-
are,
acters at the species level in Crataegus and have been considered so by Sargent,
among
Palmer, Kruschke and J.B.Phipps, others. Indeed, Kruschke (1965)
number
took an absolutist stance on the stamen issue declaring the impos-
sibility of 10 and 20-stamen entities belonging to the same species. In
examining hawthorns) Dickinson
section Douglasii (black-fruited
et
al.
(1996) have shown that 20-stamen forms are self-incompatible, often dip-
loid (and presumably always sexual) while 10-stamen forms are self-com-
may
patible, often not diploid (and be apomictic), thus providing an expla-
My
own
nation for Kruschke's viewpoint. (JBP) opinion, however, that
is
the distinction not necessarily that rigid and that this could be in part
is
due to the stage of evolutionary divergence reached at a particular point in
The number
time. point to note, however, that stamen and anther colour
is
are strong characters and that in the case of C. nananixonii they support its
edaphic Texan the time being) endemic
specific status as a rare local (for
some
rather than as a dwarfed form of other species in series Intricatae.
We
Coun-
wish to thank the National Sciences and Engineering Research
of Canada funding work, Susan Laurie-Bourque of Hull, Quebec
for this
cil
Antony Department
for preparing the illustration and Littewood of the of
The
Classical Studies, University of Western Ontario for checking the Latin
diagnosis.
Amer
Dickinson, T.A., Belaoussoff, R.M. Love, and M. Muniyamma. 1996. North
S.
black-fruited hawthorns {Crataegus sect. Douglasii Loud.): 1. Variation of floral
.
Geo
struction, breeding system and their possible evolutionary significance. Folia
31:355-371.
Phytotax.
Brown.
Hatch, K.N. Gandhi, and L.E. 1990. Checklist of the vascular plani
S.L.,
Texas.
Johnston, M.C. 1990. The vascular plants of Texas, 2nded. published by Author, Au:
Texas.
Kkuschkh, E.P. 1965. Contributions to the taxonomy oi Crataegus. Milwaukee Pul
Mus.
Public. Bot.
3.
A
MAcRouEias, D.T. 1988. documented checklist and atlas of the vascular flora of Louisi
Wm.
manmi
MAHLiiR, Shinncrs'
19H.S.
F.
Nixon, E.S. 985 Trees, shrubs and woe
1
.
Nacogdoches,
Texas.
Simpson, 1988. Field guide to Tex:
B.J.
Vines, R.A. 1960. CraUiegui In: Trees,
:
TX.
sity of Texas Press, Austin, Pp.