366 safford: myrmecophilous acacias 



rachis pubescent, bearing a raised nectar gland at the base of each 

 pair of pinnae but (in the type) none on the petiole. Pods of the same 

 general form as in the preceding section but broader and thicker, the 

 seeds enveloped in a thicker aril. 



21. Acacia tepicana sp. nov. General outline of the bipinate leaves 

 narrowl}^ oblanceolate or oblong, the pinnae short and the leaflets 

 closely crowded. Rachis 6 to 8 cm. long, reddish brown, pubescent, 

 bearing about 14 pairs of pinnae, with a pubescent beadlike or truncate 

 conoid gland at the base of each pair of pinnae, but none at the base of 

 the petiole; pinnae 10 to 18 mm. long, the shortest ones near the base; 

 leaflets 9 to 17 pairs, very small, 4.5 to 6 mm. long, 1.5 mm. broad, 

 oblong, unequal and truncate at the base, acute or short-acuminate at 

 the apex, subcoriaceous, the midrib and lateral nerves inconspicuous, the 

 margins contiguous or overlapping and bearing minute short straight 

 hairs (as seen under the microscope); lowest leaflets much smaller, 

 sometimes rudimentary, bearing a long tapering amber-colored waxlike 

 apical body. Large connate stipular spines broadly V-shaped, subterete, 

 somewhat compressed and broadened at the base, 27 mm. long, 8 or 9 mm. 

 broad at the base, brown, the surface smooth and hornlike. Small spines 

 of the abbreviated rudimentary axillary branchlets subulate, reddish 

 brown. Spikes borne on very short axillary branchlets; peduncles (only 

 those of mature fruiting specimens observed) 8 mm. long, bearing a 

 ])asal involucel; axis of spike not exceeding the peduncle in thickness. 

 Flowers not observed; interfloral bracteoles short-pedicelled, with a 

 circular disklike peltate limb 1.2 mm. in diameter. Pericarp coriaceous, 

 glabrous, without a definite dorsal suture but sometimes splitting down 

 the back, brown and glabrous outside, reddish and feltlike on the inner 

 surface, compressed, retrocurved, 13 mm. broad in the middle, narrowed 

 at the base into a stipelike neck, long-acuminate at the apex. Seeds 10 

 to 12, in a single row, ovoid, slightly compressed, about 5.2 mm. long, 

 4.2 mm. broad, and 4 mm. thick, approximate, embedded in a yellowish 

 white aril having the taste of dried apples; testa olivaceous, hard, 

 smooth and glossy, bearing a raised oval ridge on each side. 



Type in the U. S. National Herbarium, no. 637234, collected in the 

 vicinity of Acaponeta, Territory of Tepic, western Mexico, April 10, 

 1910, by Rose, Standley, and Russell (no. 14357). 



GROUP V. HEBACANTHAE 



Involucel borne at or above the middle of the peduncle. Large 

 spines puberulent when young, never becoming smooth or polished. 

 Interfloral pedicelled bracteoles not peltate, but with an ovate or fan- 

 shaped limb with a hairy margin. 



Section 9. Clavigerae 



Flowers crowded in club-shaped, cylindrical, or oblong spikes, covered 

 before anthesis with the imbricated ovoid limbs of the pedicefled brae- 



