LEGUME FAMILY (LEGUMINOSAE) 



Key to the 3 subfamilies 



A. Flowers regular, with 10 to many long, spreading stamens, separate or united at base; petals meeting by edges 

 in bud: leaves bipinnate (pinnate in In(]n) — Mimosa Sul)family ( Mimosoideae ; Mimosaeeae), this page below. 

 AA. Flowers irregular, with 10 or fewer stamens, often united ; petals overlapping in bud. 



B, Flowers only slightly irregular ; the 5 petals separate, the largest petal innermost in bud ; leaves pinnate or 

 bipinnate, sometimes of 2 leaflets or simple — Cassia Subfamily ( Cae.salpinioideae : Caesalpiniaceae), 

 page 16S. 

 BB, Flowers very irregular, beanlike or butterfly-shaped; the 5 petals being the standard (largest and outermost 

 in bud), 2 wings, and 2 slightly united forming the keel; leaves pinnate, sometimes of 3 leaflets — Pea Sub- 

 family (Lotoideae; Fabaoeae), page 1S,S. 



MIMOSA SUBFAMILY (MIMOSOIDEAE; MIMOSACEAE) 



Key to the 13 species illustrated ( Nos. 58-70 



) 

 A. Leaves pinnate, the leaflets in i)airs. 



B. Leaf axis winged ; leaflets hairy : pods nearly cylindrical, 4-angled — 64. Inga vera. 

 BB. Leaf axis cylindrical, not winged : lt>aflets hairless or nearly no; pods flattened. 

 C. Leaflets 4 (sometimes only 2) — 62. Inga laitrina. 

 CC. Leaflets usually 6 or 8 (sometimes 4) — 63. Inga quaternata.* 

 AA. Leaves bipinnate. 



T>. Leaflets very narrow, less than % inch wide, relatively long. 



E. Twigs with paired spines at nodes ; lateral axes (pinnae) 1-6. 



F. Lateral axes 1 or sometimes 2 pairs, each with 12-25 pairs of leaflets %-% inch long; spines brown 



or gray — 70. Proxapis juliflora* 

 FF. Lateral axes 2-6 pairs, each with 15-25 pairs of leaflets Vs-%6 inch long; spines whitish — 58. Acacia 

 farnesiana.* 

 EB. Twigs not spiny ; lateral axes (pinnae) 3 to many pairs. 



G. Lateral axes no more than 10 pairs. 



H. Lateral axes 3-10 pairs, each with 10-20 pairs of gray-green leaflets %6-% inch long — 65. Leucaena 

 glauca. 

 HH. Lateral axes 8-10 pairs, each with 20-40 pairs of shiny, dark green leaflets % inch long — 67. 

 PithecellobiKtn arboretim. 

 GG. Lateral axes 2(l-3."> pairs, each with 30-100 pairs of minute leaflets % inch or less in length — 66. 

 Piptadenia peregrina. 

 DD. Leaflets more than % inch broad, less than 4 times as long as broad. 

 I. Leaflets 2 pairs — GX. Pitlitcclhihium rtiilce.* 

 II. Leaflets many, lateral axes (pinnae) 2-7 pairs. 



J. Leaflets slightly diamond-shaped, asymmetrical — 69. Pithecellobium satnan.* 

 13. Leaflets oblong, rounded at apex. 



K. Leaflets oblique or asymmetrical at base. 



L. Lateral axes 2— i pairs, each with 4-9 pairs of leaflets %-l?4 inches long; the flat pods straw- 

 colored, more than 1 inch broad — 60. Albizia lebbek.* 

 LL. Lateral axes 4-7 pairs, each with t>-14 pairs of leaflets ; the flat pods rich red, turning to 

 brown, less than % inch broad — 61. .Albi'ia proccra.* 

 KK. Leaflets symmetrical, rounded at both ends, with tiny point at apex — 59. Adenanthera pavonina.* 



58. Aroma, sweet acacia 



A spiny shrub or small tree of dry areas, char- 

 acterized by: (1) the conspicuous paired whitish 

 spines (stipules) at nodes on the slijrhtly zigzag 

 twigs; (2) twice pinnate (bipinnate) leaves 2-4: 

 inches long, with 2-6 pairs of lateral axes (pin- 

 nae), each with 10-25 pairs of naiTOw (linear or 

 oblong) stalklessleafletsV8-%6 inch long; (3) very 

 fragrant flowers in bright yellow balls (lieads) 

 about 1/2 iiich across the numerous stamens, on 

 lateral stalks; and (4) dark brown to blackish 

 pods 11/2-3 inches long and %-y2 inch broad, 

 straight or slightly curved, 1-3 on a stalk. 



A deciduous shrub usually less than 10 feet high 

 or sometimes a small tree, much branched and 

 spreading. The bark is dark brown and smooth- 

 ish. The twig.s are dark brown with light colored 

 dots (lenticels) and with paired .spines Vg-^ inch 

 or more in length. 



Often the alternate leaves are crowded on short 

 spur twigs and appear to be more than 1 at a 

 node. The slender hairy axis bears a minute round 



142 



Acacia farnesiana (L.) Willd.* 



gland. The thin green leaflets sometimes as much 

 asVie i'lch long are short-pointed at apex, rounded 

 at base, and hairless or sometimes hairy around 

 edges. 



Flower heads are borne 1-3 together on hairy 

 stalks %-l% inches long and composed of numer- 

 ous narrow flowers about 14 inch long ending in 

 very many yellow threadlike stamens. The tubu- 

 lar .5-toothed calyx is i/jg inch long; the tubular 

 5-toothed corolla is Vg inch long; there are many 

 threadlike stamens almost Y^ inch long; and pistil 

 3/16 iiif'h long of narrow ovary and .slender style. 



The pods are thick and only slightly flattened 

 and only a little narrowed between the seeds, 

 contain sweetish pulp, and open late. There are 

 several brown seeds, elliptic and slightly flattened, 

 ■%(; inch long. Kecorded in flower from November 

 to February. The fruits remain attached after 

 maturing. 



The sapwood is yellowish and the heartwood 

 reddish brown. The wood is hard and heavy 



