Senna 
CAESALPINIACEAE 37 
3. | Procumbent perennial with annual aerial stems; leaflets linear-oblong 
to narrowly elliptic, 7-15 mm Wide... 
S. procumbens 
3. Erect shrubs or trees; leaflets elliptic, obovate or lanceolate, 
MOS Ys broad etrrectaraiscteristeortseestesertitersnttittertess 
4. Leaf rachis >80 mm long 
4. — Leaf rachis <80 mm Jong .........cccscsssssssesssssteseeeeeeeeeee 
5. Annual; gland on leaf rachis just above pulvinus; leaflets acute .........cseccesseeseeeeeseeeeeees 
i}, Perennial shrub or tree; erect terete glands between 
lower 2-4 leaflet pairs; leaflets obtuse ...........00 
6. Perennial; stipules absent; stamens all perfect ............ 
6. Annual; stipules linear; staminodes present .............+. 
Tk Gland between lower 2 leaflet pairs; anthers truncate 
7. Gland between basal pair of leaflets only; anthers beaked ...........ccccsssssessseseseseseteseeeseees 
*S. alata (L.) Roxb. 
Cassia alata L. 
Evergreen shrub to 4 m, minutely tomentose on 
leaves, stems and calyx. Stipules persistent, broad- 
based, 5-8 mm long. Leaves terminated by a 
bristle, sunken gland at base of rachis, rachis 
290-500 mm long; leaflets 8-11 pairs, oblong to 
obovate, 30-170 mm long, 20-102 mm wide, 
L/W 1.1-2.8. Inflorescence erect, axillary or terminal 
racemes to 500 mm long. Bracts caducous, brown, 
membranous, obovate, 20-28 mm long, covering 
bud; bracteoles absent. Pedicels 4-8 mm long. Sepals 
elliptic to obovate, 12-17 mm long. Petals + 
orbicular, 12-20 mm long. Stamens 10, 2 large, 5 
medium-sized, 3 small; style short, curved, beaked. 
Ovary hairy. Pods dark brown to black, stipitate, 
4-angled including 2 broad crenate membranous 
wings, 130-185 mm long, 14-24 mm wide. Seeds 
numerous, transverse, lying at right angles to axis of 
pod, rhomboid, flattened with central rib, dark grey 
to black, c. 6 x 4.5 mm. Flowering: May - June; fruits 
persist throughout year. Fig. 14 Candlebush 
Originally from S America, now a pantropic weed 
or ornamental. From Qld to the NT; common in the 
DR associated with perennially moist areas. 
S. leptoclada (Benth.) Randell 
Cassia leptoclada Benth. 
Perennial glabrous shrubs to 2 m. Stipules absent. 
Leaves with conical jugary glands present, rachis 
(3)20-60 mm long; leaflets (1)2-3 pairs, subglaucous, 
elliptic to obovate, slightly asymmetric at base, 
10-44 mm long, 5-27 mm wide. L/W 1.3-2.2. 
Inflorescence axillary, a reduced raceme, often 
umbelliform. Bracts 2-3 mm long; bracteoles absent; 
peduncle 5-24 mm long; pedicels 10-18 mm long. 
Sepals unequal, elliptic to + orbicular, 3.5-6 mm long. 
Petals obovate to + orbicular, 9-18 mm long. 
retrtirencteseertenartrtperecscurcenrttrreretertte? 7 
ctrsreunmipenrtenttrtdietertdresred ets 4 
5 
6 
S. occidentalis 
S. surattensis 
S. leptoclada 
S. tora 
S. obtusifolia 
Stamens 10, equal, beak absent. Pods brown, stipitate, 
oblong and slightly curved with persistent stigma, 
broadly crenate, 15-60 mm long, 9-12 mm wide. 
Seeds 1-8, black, oblique in pod, narrowly oblong, 
5-6 mm long, 3-4.mm wide. Flowering and fruiting: 
for most of the year. Fig. 14 
Restricted to sandstone in Arnhem Land, the Gulf 
of Carpentaria and Mt Douglas in the DR. 
*§S. obtusifolia (L.) Irwin & Barneby 
Cassia obtusifolia L. 
Annual shrub to 2 m. Indumentum of sparse, 
simple, white hairs. Stipules persistent, linear, 
8.5-20 mm long. Leaves terminated by a bristle, 
2-3 pairs of leaflets, pulvinus drying dark, erect 
terete gland between basal pair, rachis to basal 
leaflets 8-50 mm long, rachis 20-80 mm long; 
leaflets 2-3 pairs, obovate to broadly spathulate, 
base slightly asymmetric, 21-67 mm long, 12-36 mm 
wide, L/W 1.4-2.4. Inflorescence an axillary reduced 
raceme; peduncle c. 1 mm long, flowering pedicels 
7-16 mm long, pedicel and receptacle with colleters. 
Bracts like stipules, 3-6.5 mm long; bracteoles 
absent. Sepals unequal, elliptic, ciliate, 4-9 mm long. 
Petals obovate, subequal, 10-11 mm long. Functional 
stamens 5-7, shortly beaked; staminodes c. 3. Ovary 
hairy, sessile. Pods on pedicel 18-25 mm long, brown, 
stipitate, ribbed on each margin, slightly flattened, 
linear, Seeds oblique but pod with transverse septa, 
rhomboid, slightly flattened, brown to olivaceous, 
4.3-5.5 mm long, 2.7-4 wide, areole longitudinal, 
c. 0.5 mm wide. Flowering and fruiting: Feb - Aug. 
Fig. 14 
Probably a native of tropical. America, new a 
widespread weed. Recorded from northern NT and 
Qld. In the DR often in dense swards on moist 
disturbed areas on the margins of the coastal flood- 
plains. 
