Download Studies on the Flora of Northern South America-IX

SouthAmerica-IX'
Studieson thefloraofnorthern
H. A.
MISCELLANEOUS
NEW
GLEASON
SPECIES
FROM
BRITISH
GUIANA
Tetrapodenian. gen. Malpighiaceae; arborescent,the young
branches stronglyflattened; stipules axillary, connate, erect;
leaves opposite,petiolate,coriaceous,entire; flowersin minutely
bracted, terminal racemes, on jointed pedicels; bracteoles 2,
the lower glandular; calyx io-glandular; petals 5, clawed,
fouressentiallyalike, the fifthmuch smaller,its blade bearing
two pairs of latero-basal,stipitate,reniformglands; stamens IO,
the fiveopposite the sepals the longer;filamentsshort,glabrous,
and barelyconnate at base; anthers
somewhattriangular-dilated
or triangular-prismatic
semicylindric
simple,
the
stout,
elongate,
connectivestruncate to broadly rounded at the apex; pollensacs 4, elongate,strictlyparallel in the longerstamens,slightly
divergentdistally in two pairs in the shorter;ovary depressedhemispheric,3-celled,glabrous; styles3, glabrous,bent near the
tip at rightanglesand graduallytaperingdistallyto theobliquely
truncateterminalstigma;fruitindehiscent,I-celled and I-seeded
by abortion,subellipsoid,theexocarpthickand woody,the endocarp chartaceous; seed ellipsoid, the small cotyledon partly
enclosed by the large.
to
The name is combinedfrom:rspa, 70'q, and ac6'v,referring
the fourstalked glands on the fifthpetal.
Tetrapodenia glandifera n. sp. Tree 4-6 m. high; young
branches stronglycompressed,glabrous, later becoming terete
and roughenedby elongatelenticels;stipulestriangular-subulate,
erect, stiff,6-8 mm. long, densely pubescent above; petioles
IO-I5 mm. long, glabrous,flattenedor barely channeled above;
leaf-blades stiff,coriaceous, dull green, elliptic-oblong,IO-I7
cm. long, 4.5-8.5 cm. wide, abruptly acute or subacuminate,
entire,broadly cuneate to obtuse or rounded at base, glabrous
above, glabrous beneath (except under strong lens minutely
lepidote) and biglandular at the base; veins and veinlets prominulouson both sides, conspicuouslyreticulate;racemessingle
or in threes,terminatingthe branches,the axis somewhat flattened and minutelypuberulent,the bracts broadly ovate-triangular,I-2 mm. long; pedicels7-8 mm. long,glabrous,jointed
in the middle,bearingop the lowersegmenttwo broadlyovate,
amplexicaulbracteolesI.5 mm. long, the lowerof whichbears a
conspicuousgland; calyx-glandsIO, cuneate-obovate,adnate to
Contributionsfromthe New York Botanical Garden,no. 282.
289
290
BULLETIN
OF
THE
TORREY
CLUB
[VOL.
53
the summit of the pedicel; sepals triangular,acute or barely
retuse, exceeding the glands by I.3 mm.; petals dimorphic,
clawed, the four larger with semiorbicular,subentire blade,
cleftat base to the insertionof the claw, the fifthmuch smaller,
obovate-oblong,with stout fleshyclaw, the basal pair of glands
o.6 mm. in diameter,on stipes o.s mm. long, the distal pair half
as large,on stipesone thirdas long; filamentsflat,glabrous,3 or 2
mm. long, dilated and barely connate at base; anthers stout
2-2.5
mm. long in bud, the simple connective somewhat surpassing the narrowlylinearpollen-sacs;fruitsmooth,20-25 mm.
long by I2-IS mm. in diameter,rounded at base, subacuminate
to the blunt apex whichis markedby 6 faintradial furrows.
Type, La Cruz 3515, collected at Amakura, NorthwestDistrict, British Guiana, 23-30 March I923, and deposited in the
herbariumof the New York Botanical Garden. La Cruz 2176,
fromthe upper Mazaruni River,collectedthe precedingautumn,
agrees with the type in all vegetative characters,except some
small differences
in texturedue to age, and exhibitsmaturefruit
and old flowersfrom which the petals have fallen. La Cruz
2869, withmaturefruit,and 2013, sterile,bothfromtheMazaruni
region,differfromthe firsttwo in theirlarger,proportionately
narrower,and more sharply acute leaves which are distinctly
shining above. The fruitis preciselythe same. The specific
descriptionis drawn entirelyfrom the type, except that the
lengthof the filamentsis measuredfromthe witheredflowersof
2i76.
Duplicates of all four numbers are to be found in the
leading Americanherbaria.
Tetrapodeniais obviously closely related to Glandonia and
Burdachia,two generaof the northernAmazonian forestswhich
are still poorly known and have probably not been collected in
recent years. The formeris monotypic,but both flowersand
fruitare known and were carefullydescribed by Grisebach in
the Flora Brasiliensis. The lattercontains two species, but the
flowers of only one are known. Tetrapodenia differsfrom
Glandoniain its hirsutestipules,the glands on the lowersurface
of the leaf, the differentiated
fifthpetal, the unappendaged anther-sacs,the shape of the fruit,and the presenceof two cotyledons. From Burdachia prismatocarpa,it is distinguishedby
the glabrous,depressed-hemispheric
ovary,the simpleblunt connectives,the characterof the fifthpetal, and the shape of the
fruit. From Burdachia sphaerocarpa,the flowersof which are
not known,it differsin its glabrousstipulesand the shape of the
fruit.
19261
GLEASON:
NEW
SPECIES
FROM
BRITISH
GUIANA
29I
Te/rapodenia
glandiferais representedin the herbariumof the
Royal Botanic Garden at Kew by two collectionsby Jenman,
3779 and 6413.
Combretum brunnescens n. sp. Shrubby vine, climbing
6 m.; stems glabrous, stronglyfurrowedand flattenedabove,
becomingtereteand barely striatein age, the upper internodes
5 cm. long; petiolesstout, dark brown,6-IO mm. long, angular,
glabrous;leaf-bladescoriaceous,olive-brownwhendried,broadly
elliptic-obovate,70-85 mm. long, 43-58 mm. wide, obtuse to
subrotundat base, entire,broadly roundedabove and minutely
apiculate, shiningabove, glabrouson both sides; lateral veins 5
or 6 pairs,lightlyimpressedabove, prominentbeneath,ascending
at an angle of 600 and nearly straight,the veinlets obscure;
panicles freelybranched, terminal and from the upper axils,
IO cm. long; spikes spreading,5-6 cm. long, the rachis strongly
angled,glabrous; bracts subulate,puberulent,0.5-I.I
mm. long;
ovarysessile,linear-oblong,
I.I-I.3
mm.long,0.4 mm. in dr-
ameter,obtusely 4-angled, glabrous or minutelyvillous; calyx
campanulate, glabrous,conspicuouslybut minutelyred-dotted,
1.7 mm. long, including the broadly triangular,acute teeth
mm. long, glabrous within; petals white, transversely
0.4-0.5
elliptic,1.4 mm. wide,o.8 mm. long,glabrous,with a shortclaw
0.1 mm. long; stamens 8, insertednear the bottomof the calyx,
the filamentswhite,glabrous, subulate, 4 mm. long, somewhat
incurvedat three-fourths
of theirlength,the anthersobcordate,
0.4 mm. long and wide; disk a minuteglabrousringat the bottom
of the calyx; style straight,white,subulate, 2.8 mm. long.
Type, La Cruz 3566, collected along the Amakura River,
NorthwestDistrict, BritishGuiana, lat. about 8? IO' N., long.
about 600 XV.,23-30 March 1923, and deposited in the herbarium
of the New York Botanical Garden.
The type of Combretum
brunnescenshas been chosen arbitrarilyfromseveralspecimensin the herbariumof the New York
Botanical Garden, all collected in the same general region.
Duplicates of most of them have been distributedto the larger
Americanherbaria. These are La Cruz iog4 and iiji fromthe
Pomeroon District, 3425, 3585, and 3713 from the Northwest
District, 1947 fromnear Bartica, 4258 fromKamakusa, upper
Mazaruni River, and 4460 fromKaieteur Falls, Potaro River.
All but the last two of these are in flowerand differfromthe
type onlv in minordetails. In two fromthe PomeroonDistrict
the largest leaves are only 6 cm. long; in all except I947 and
3425 the leaves are moreshiningabove; in 1141, 1947, 3585, and
3713
the terminalapiculum of the leaf is more developed and