VOL. 35 1982 - Duke Herbarium

468
MEMOIRS OF THE NEW YORK BOTANICAL GARDEN
[VOL. 35
mm; ovary densely yellowish- or pallid-pilosulous; style linear, gently incurved
distally 7.5-12 mm, just below stigma 0.2-0.4 mm diam; ovules ±12-17.
Pod stiffly ascending or randomly spreading-declined, the stipe 7-11 mm, the
linear-oblong, strongly compressed body 7-12 x (1.5-)1.7-2.3(-2.5) cm, bicarinate by the sutures, the fuscous-green, finally papery nigrescent valves finely
pilosulous with short sometimes mixed with longer white hairs, corrugate by low
obtuse ridges elevated over each seed, finely transverse-venulose, the locules
between the narrow membranous interseminal septa 4-5.5 mm long, occupying
the whole width of cavity; seeds oblong narrowed proximally, compressed parallel to the valves, 6-8.2(-"9") x 3^4.6(-"5") mm, the testa pale tan sometimes
overlain with fuscous-green, smooth or obscurely pitted, moderately lustrous,
crackled in age, the oblong-elliptic areole 3-4 x 0.7-1.!(-"!.5") mm.—Collections: 30.
Savanna thickets, margin of forest galleries, lake shores and riverbanks, becoming colonial and weedy in old fields, coppiced woodland and on roadsides,
widespread in tropical Africa, whence introduced into tropical and warm temperate horticulture, sporadically naturalized in s. India, Sri Lanka, Malesia, s.
peninsular Florida, apparently only cultivated in s. California, Cuba, Mexico,
Panama.—Fl. in N. America mostly XII-II.
This coarsely handsome but ill-scented African senna, occasionally cultivated
in North America and liable to become naturalized in frostless regions, resembles
our native S. nicaraguensis and S. martiana in the narrow multifoliolate leaves
and the massive erect racemes capped by a cone of dilated bracts. At anthesis
it differs from both in the symmetrically cordate stipules and the less highly
colored, usually fuscous rather than orange-yellow floral bracts, further from S.
nicaraguensis in the short filaments of the two large abaxial stamens, and further
from S. martiana in the essentially simple pinnate rather than reticulate venulation of the leaflets. The simply corrugate, not crested or umbonate pod of S.
didytnobotrya is decisively characteristic.
152. Senna centranthera Irwin & Barneby, sp. nov., S. nicaraguensi affinis eique
quoad perianthium ac androecium persimilis, sed stipulis parvis (6-10
nee 10-35 mm longis) baud dimidiatis nee semicordato-amplexicaulibus, bracteis parvis (2-7.5 nee 18-25 mm longis), foliolis simul duplo
numerosioribus (15-33 nee 10-16-jugis) ac dimidio brevioribus (15-40
nee 35-80 mm longis), sepalisque minoribus (9-11.5 nee 13-21 mm
longis) manifeste diversa.—MEXICO. Jalisco: w. slope of mountains
11 mi. s. of Autlan, 1350 m, 25.IX.1966 (fl), W. R. Anderson & C. W.
Laskowski3745.—Holotypus, NY; isotypi, GH, USj 3>vM«E
Arborescent shrubs with trunk to 3(-?) cm diam, becoming 4-5 m tall, the
hornotinous branches densely clad in long multifoliolate Ivs and terminating in
an ample panicle of many-fld racemes, except for the glabrous upper or both
faces of the dull olivaceous, either subcon- or discolorous Ifts and for the dorsally
glabrous sepals commonly pilosulous throughout with spreading-ascending pale
hairs to 0.2-0.45 mm, sometimes glabrate except for residually puberulent Ifstalks, the panicle of racemes at least distally leafless and exserted from foliage.
Stipules early reflexed, herbaceous, deltate-ovate-acuminate or broadly lanceolate 6-12 x 2.5—5(—6) mm, deciduous.
Lvs 15-35 cm; petiole including little swollen but discolored pulvinus 2-3.5 cm,
at middle 1-1.6 mm diam, rounded dorsally, narrowly winged and open-sulcate
ventrally, the wings of If-stalk segments slightly widened upward and the sulcus
1982]
there deeper; petiolar glands
the rest not or little graduated,
dilated pulvinule 0.7-1.3 mm,
elliptic, obtuse mucronulate (
wide, at strongly assymmetri
distally, the slender midrib v
some intercalary secondary v
venulation yet finer, scarcely
Racemes crowded along a s
bracteate, at first densely then
fls standing well below the un
7-20 cm; bracts submembran
from below young buds at fi
anthesis 9-16 mm; fl-buds o
nutely ciliolate sepals glabroi
posed in vernation, the inne:
cave, finely many-nerved fn
broader, the longest 9-11.5 rr
all glabrous, little heteromor
ovate-cuneate beyond the si
abaxial pair, the longest 13-2
the filaments of 4 median sta
the anthers of 4 median and
size, shallowly sigmoid 3—4.'
large abaxial ones lunately i
distally into an erect beak i
slits, all anthers strongly dor
descending spurs of the large
a filiform incurved or hooke<
Pod obliquely pendulous, t
cm, strongly piano-compress
at length stiffly papery valves
the seed-locules ±4 mm long
the pod's width; seed unkno
Seasonally wet open woo
vanna, sometimes on pedr
1350-2000 m, local along th
Jalisco (mun. Autlan), w. N
and Coalcoman), Guerrero (i
Juxtlahuaca), Mexico.—Fl.
Senna centranthera appeE
araguensis, morphologically
simultaneous doubling in n
appear a priori that this evol
and ample colored bracts mi
In the narrower context of s
have made independent par;
Africa and Australia, which
conventional ones found in
below.
The range, habitat and su
incide with those of S. (sect
CAL GARDEN
[VOL.
35
style linear, gently incurved
iam; ovules ±12-17.
tied, the stipe 7-11 mm, the
,5-)1.7-2.3(-2.5) cm, bicariery nigrescent valves finely
/hite hairs, corrugate by low
iverse-venulose, the locules
i 4-5.5 mm long, occupying
>roximally, compressed parthe testa pale tan sometimes
pitted, moderately lustrous,
7_l.i(_"l.5") mm.—Collecshores and riverbanks, betvoodland and on roadsides,
nto tropical and warm temidia, Sri Lanka, Malesia, s.
California, Cuba, Mexico,
nna, occasionally cultivated
frostless regions, resembles
narrow multifoliolate leaves
f dilated bracts. At anthesis
stipules and the less highly
loral bracts, further from S.
abaxial stamens, and further
ather than reticulate venulated or umbonate pod of S.
S. nicaraguensi affinis eique
lis, sed stipulis parvis (6—10
: semicordato-amplexicaulilongis), foliolis simul duplo
: dimidio brevioribus (15-40
bus (9-11.5 nee 13-21 mm
isco: w. slope of mountains
), W. R. Anderson & C. W.
I, GH, USj DOKE
i, becoming 4-5 m tall, the
olate Ivs and terminating in
the glabrous upper or both
irous Ifts and for the dorsally
th spreading-ascending pale
for residually puberulent Ifs and exserted from foliage,
^-acuminate or broadly laniscolored pulvinus 2-3.5 cm,
/ly winged and open-sulcate
ened upward and the sulcus
1982]
CASSIINAE—SENNA
469
there deeper; petiolar glands 0; Ifts 20-33 pairs, the proximal ones smaller but
the rest not or little graduated, all ascending from rachis, face upward, on scarcely
dilated pulvinule 0.7-1.3 mm, in outline lance- to narrowly ovate-oblong or lanceelliptic, obtuse mucronulate (8-) 15-40 x (3-)4-12 mm, 2.7-4 times longer than
wide, at strongly assymmetric base rounded on both sides or broadly cuneate
distally, the slender midrib with ±8-10 pairs of major camptodrome and often
some intercalary secondary veins finely prominulous on both faces, the tertiary
venulation yet finer, scarcely raised.
Racemes crowded along a straight primary axis 1-2.5 dm, the lower ones leafybracteate, at first densely then loosely 10-45-fld, the 1-2 simultaneously expanded
fls standing well below the unopened buds, the axis including peduncle becoming
7-20 cm; bracts submembranous lance- or ovate-acuminate 2-4.5 mm, caducous
from below young buds at first elongation of pedicel; pedicels at and after full
anthesis 9-16 mm; fl-buds obovoid-ellipsoid obtuse, except for sometimes minutely ciliolate sepals glabrous; sepals submembranous, brown except where exposed in vernation, the inner ones subpetaloid, all broadly oblong-elliptic concave, finely many-nerved from base, subequal in length but the inner a little
broader, the longest 9-11.5 mm; petals yellow drying stramineous brown-veined,
all glabrous, little heteromorphic but varying from broadly oblanceolate to obovate-cuneate beyond the slender claw, the 3 adaxial a trifle longer than the
abaxial pair, the longest 13-20 mm; androecium glabrous, functionally 2-merous,
the filaments of 4 median stamens 1.8-2.5 mm, of the 3 abaxial ones 3.3-5 mm,
the anthers of 4 median and the centric abaxial one sterile or greatly reduced in
size, shallowly sigmoid 3^.5 mm, with porrect beak 0.7-1.3 mm, those of the 2
large abaxial ones lunately incurved 10-14 mm, almost imperceptibly narrowed
distally into an erect beak dehiscent by minute terminal, ultimately confluent
slits, all anthers strongly dorsoventrally compressed, sagittate at base, the acute
descending spurs of the larger anthers 1.5-2.5 mm; ovary glabrous, narrowed into
a filiform incurved or hooked style 4.5-6.5 mm; ovules ±24-30.
Pod obliquely pendulous, the stipe ±3 mm, the broadly linear body 7-11 x ± 1.4
cm, strongly piano-compressed and carinate by the sutures but the lustrous green,
at length stiffly papery valves raised over each seed as a prominent fuscous umbo,
the seed-locules ±4 mm long and twice as wide, occupying a little more than half
the pod's width; seed unknown.—Collections: 12.—Fig. 28.
Seasonally wet open woodland and semi-deciduous scrub thickets in hill-savanna, sometimes on pedregal and probably confined to volcanic bedrock,
1350-2000 m, local along the Pacific slope and crest of Sa. Madre del Sur in s.
Jalisco (mun. Autlan), w. Michoacan (mun. Tsitsio, Quitupan, Cotija de la Paz
and Coalcoman), Guerrero (mun. Tixtla and Chilpancingo), and w. Oaxaca (distr.
Juxtlahuaca), Mexico.—Fl. VI-XI.—Palo Maria.
Senna centranthera appears to be a submontane derivative of lowland S. nicaraguensis, morphologically modified by reduction of stipules and bracts and by
simultaneous doubling in number and halving in size of the leaflets. It might
appear a priori that this evolutionary sequence is reversed, for foliaceous stipules
and ample colored bracts must surely be advanced features in Senna as a whole.
In the narrower context of ser. Pictae, however, the petaloid bracts, unless they
have made independent parallel appearances in North America, South America,
Africa and Australia, which seems unlikely, are antecedent to the smaller, more
conventional ones found in S. centranthera and its Andean kindred described
below.
The range, habitat and superficial gross aspect of S. centranthera roughly coincide with those of S. (sect. Chamaesenna) multifoliolata and possibly may give
470
MEMOIRS OF THE NEW YORK BOTANICAL GARDEN
[VOL. 35
1982]
rise to misidentification. r.
importantly the androecii
pod, are the fundamental]
153. Senna pistaciifolia (H
nov. Cassia pi
& Sp. 6(folio):
taciifolia indie;
Fig. 28. Senna centranthera I. & B. Flowering branchlets xVi; flower x2; detached stamens x5
(Anderson & Laskowski 3745); pod xl (Barneby 17773).
Amply leafy shrubs wil
at anthesis mostly 0.8-2..
appearing and sometimes
of Ifts and axes of inflore
hairs up to 0.4-0.7 mm, tli
paler beneath, the loosel
either immersed in foliagi
terminal depauperately le;
Stipules (caducous, p
3-12 x 1.5-3 mm, ± dila
striate-nerved.
Lvs (0.7-)!^ dm; petio
at middle 0.7-2.3 mm diai
plano-sulcate ventrally; re
accrescent distally but the
pair broadly oblanceolate,
cm, ±2-3 times as long as
emarginate, commonly co
inequilaterally rounded 01
side, the midrib centric st
dom intercalary) secondai
inulous on both faces, a
raised mesh of areoles vai
Racemes loosely 10-4
(0.5-)0.7-3 dm; bracts firn
lance-acuminate, together
caducous as the pedicels 1
fruiting spms; pedicels at
obovoid or oblong-obovoi
graduated, oblong or obo
membranous-margined, th
dried whitish brown-veine
vexillar petals oblanceolat
abaxial always obovate, tl
petal 15-22 mm; androeciu
mm, of 3 abaxial ones 3-5
the anthers of 4 median s
curved 3-5 mm, abruptly
those of the 2 latero-abaxi;
erally sagittate (the longer
tracted below a short 2-lip
anther sterile, 2.5-3 mm, it
glabrous or strigulose; sty]
AL GARDEN
[VOL.
35
1982]
%t
CASSIINAE—SENNA
471
rise to misidentification. The glandless leaf-stalk, the exserted panicle, and most
importantly the androecium proper to sect. Senna, not to mention the cristate
pod, are the fundamentally distinctive characters of S. centranthera.
/r, flower x2; detached stamens x5
153. Senna pistaciifolia (Humboldt, Bonpland & Kunth) Irwin & Barneby, comb,
nov. Cassia pistaciifolia Humboldt, Bonpland & Kunth, Nov. Gen.
& Sp. 6(folio): 349 ("pistaciaefolia"). 1824.—Typus infra sub var. pistaciifolia indicator.
Amply leafy shrubs with smooth terete hornotinous branches and branchlets,
at anthesis mostly 0.8-2.5 m, reportedly sometimes arborescent to 10 m, often
appearing and sometimes truly glabrous but the young stems, If-stalks, lower face
of Ifts and axes of inflorescence sometimes puberulent or pilosulous with weak
hairs up to 0.4-0.7 mm, the stiffly membranous Ifts dull olivaceous on both faces,
paler beneath, the loosely many-fld racemes at first axillary to distal Ivs, then
either immersed in foliage or exserted, some smaller later ones often forming a
terminal depauperately leafy or leafless panicle.
Stipules (caducous, poorly known) firm erect obliquely lance-acuminate
3-12 x 1.5-3 mm, ± dilated at base on the side further from petiole, strongly
striate-nerved.
Lvs (0.7-)1^1 dm; petiole including moderately swollen pulvinus (l-)2.5-7 cm,
at middle 0.7-2.3 mm diam, rounded dorsally, very narrowly thick-margined and
plano-sulcate ventrally; rachis (2-)3-24 cm; petiolar glands 0; Ifts 3-10(-ll) pairs
accrescent distally but the penultimate one sometimes largest, this and the distal
pair broadly oblanceolate, oblong-obovate or elliptic (3.5-)4.5-10.5 x (1.2-)1.5-4.7
cm, ±2-3 times as long as wide, at apex broadly rounded, deltate or (if damaged)
emarginate, commonly conspicuously mucronate, at base (when relatively broad)
inequilaterally rounded or subcordate or (when narrower) cuneate on the distal
side, the midrib centric straight, the 10-16 pairs of camptodrome (and often random intercalary) secondary veins with tertiary and reticular venulation all prominulous on both faces, a trifle more sharply so dorsally, there going out into a
raised mesh of areoles variable in size but the smallest 0.5 mm or less diam.
Racemes loosely 10-45 fld, the axis together with peduncle becoming
(0.5-)0.7-3 dm; bracts firm, not or scarcely colored, ovate apiculate or ovate- or
lance-acuminate, together forming around the very young fl-buds a small cone,
caducous as the pedicels begin to elongate, absent from many flowering and all
fruiting spms; pedicels at and after full anthesis 12-20 mm; fl-buds obliquely
obovoid or oblong-obovoid obtuse, glabrous or thinly puberulent; sepals little
graduated, oblong or obovate obtuse 8-14.5 mm, either yellowish or fuscous,
membranous-margined, the tips cucullate; petals yellow with darker veins, when
dried whitish brown-veined, glabrous, heteromorphic, all 3 adaxial or only the
vexillar petals oblanceolate to narrowly obovate, the 2 lateral sometimes and 2
abaxial always obovate, the latter obliquely so and usually largest, the longest
petal 15-22 mm; androecium glabrous, the filaments of 4 median stamens 1.3-2.5
mm, of 3 abaxial ones 3-5.5 mm, those of 2 latero-abaxial ones much thickened,
the anthers of 4 median stamens oblong, dorsoventrally compressed, little incurved 3-5 mm, abruptly contracted into a porrect biporose beak 0.7-1.4 mm,
those of the 2 latero-abaxial ones lunately incurved 13-16 mm, at base inequilaterally sagittate (the longer descending spur 2.5-3 mm), at apex very slightly contracted below a short 2-lipped beak, the upper lip 2-porose, the central abaxial
anther sterile, 2.5-3 mm, its basal lobes spreading-decurved ±1 mm; ovary either
glabrous or strigulose; style 4.5-6.5 mm, subfiliform slightly dilated toward the