352 ZYGOPHYLLACEAE. {Vor. Il. 
1.’ TRIBULUS aj: Spb) 3875 290753: 
Herbs, mostly prostrate, with evenly pinnate leaves and peduncled axillary yellow 
flowers. Sepals 5, persistent. Petals 5, deciduous. Stamens 1o, the alternate ones some- 
what longer. Ovary sessile, 5-lobed, 5-celled, hairy, the hairs erect; style short; stigma 5- 
ridged; ovules 3-5 in each cavity, pendulous. Fruit 5-angled, spiny, splitting into 5 3-5- 
seeded segments. [Greek, three-pronged, Caltrop, from the resemblance of the fruit to that 
implement. ] 
About 12 species, natives of warm and tropical regions. Besides the following, another occurs 
in the southwestern States. we 
No SAE 
1. Tribulus terréstris L. Ground Bur- GB 2 SSS 
nut. Land Caltrop. (Fig. 2267.) 
Tribulus terrestris 1. Sp. Pl. 387. 1753- 
Annual, pubescent, branched from the base, the 
stem prostrate or ascending, sometimes 1° long 
or more. Leaves petioled; stipules small; leaflets 
4-8 pairs, oblong, inequilateral, opposite, short- 
stalked, acutish or obtuse, 3//-8’’ long; flowers 
solitary, about 6’’ broad, peduncled; peduncles 
shorter than the leaves; petals oblong, about as 
long as the sepals; segments of the fruit usually 
with 2 long spines, 2 shorter ones, and a row of 
very short ones forming a crest on the back, also 
commonly with some bristle-like hairs. 
In ballast and waste places about the eastern sea- 
ports, andincentral Nebraska. Fugitive from Europe. 
June-Sept. 
2. KALLSTROEMIA Scop. Introd. 212. 1777. 
Mostly annual branching pubescent herbs, the branches often prostrate, with opposite 
stipules, evenly pinnate leaves, and solitary axillary peduncled yellow flowers. Sepals 
usually 5, persistent or deciduous. Petals the same number, obovate or oblanceolate, decidu- 
ous. Stamens twice as many as the petals. Ovary sessile, 1o-12-celled; ovule 1 in each 
cavity, pendulous; style long, or short, 10-12-grooved, persistent; stigma mostly 10-12- 
ridged. Fruit 10-12-lobed, not spiny, often tubercled, splitting into ro-12 1-seeded segments. 
[In honor of Kallstroem. ] 
About 10 species, of wide distribution in warm and tropical regions. Besides the following, 3 
others occur in the southern and western States. 
WZ 1. Kallstroemia maxima (L.) T. &G. 
Greater Caltrop. (Fig. 2268.) 
Tribulus maximus 1. Sp. Pl. 387. _1753- 
Kalistroemia maxima T, & G. Fl. N. A. 1: 213. 1838. 
Annual, branches slender, prostrate, 6’-18’ long. 
Leaves short-petioled; stipules subulate, shorter than 
the petioles; leaflets 3-5 pairs, oval, or oblong, inequi- 
lateral, acute or obtuse at the apex, rounded or subcor- 
date at the base, 4’’-10’’ long; peduncles slender, 6’’—2’ 
long in fruit; flowers 1/ broad, or less; sepals linear- 
lanceolate, very pubescent, persistent, shorter than the 
petals; fruit ovoid-conic, about 3’’ in diameter, about as 
long as the stout persistent style, the segments tuber- 
cled. 
In dry soil, Kansas to Georgia, Florida and Texas. Also 
in tropical America. April-Sept. 
Family 54. RUTACEAE Juss. Gen. 296. 1789. 
RUE FAMILY. 
Trees or shrubs, rarely herbs, with heavy-scented and glandular-punctate 
foliage, alternate or opposite mainly compound exstipulate leaves, and (in our 
species) polygamo-dioecious generally cymose flowers. Sepals 4-5, or none. 
Petals 4-5, hypogynous or perigynous. Stamens of the same number, or twice 
as many, distinct, inserted on the receptacle; anthers 2-celled, mostly versatile. 
Disk annular. Pistils 2-5, distinct, or 1 and compound of 2-5 carpels, inserted 
