PITTIER TREATMENT OF THE GENUS CASTILLA. 



269 



5. Castilla lactiflua Cook. Science n. ser. 18:43S. 1903. 



Plates 20-28. Figure 48. 



A medium-sized tree attaining 25 meters and over. Young twigs densely 

 hairy, a thick white pith within. 



Leaves rather large. Petioles 1.5 cm. long, thick, hairy. Leaf blades 30 to 

 45 cm. long, 10 to 15 cm. broad, deep green, rough and covered with scattered 

 hairs above, paler and hairy beneath; midrib and the 20 to 24 primary veins 

 hairy and little prominent on the upper face, the whole venation more marked 

 and thickly covered with stiff hairs on the lower face; margin obscurely sinuate, 

 with tufts of longer, erect hairs between the sinuses. Stipules caducous, 4.5 

 to 7 cm. long, rather broad, hairy and longitudinally ribbed outside, purplish 

 and smooth inside. 



Receptacles of the primary male inflorescence 2 or 3-geminate, small (1.5 to 

 2 cm. long and broad), the lobes flat, flabellate, more or less cordiform or 

 kidney-shaped. Stipes very short (5 to 7 mm. long), bearing a few free, 

 lanceolate-acuminate bracts. Scales numerous, in 5 to 

 7 imbricate rows, small (about 4 mm. long, 3 nun. 

 broad), irregularly ovate-lanceolate, velvety, freer and 

 narrower toward the margin, interstaminate bracts 

 few. irregularly shaped, hairy and ciliate, about the 

 length of the filaments. Stamens 2.5 to 4 mm. long, 

 glabrous, numerous, single or in clusters; filaments 2 

 to 3 mm. long; connective large, scutellate; anther 

 cells narrow. 



Receptacles of the complemental male inflorescence 

 geminate, about 1.5 cm. long, flabellate. with a slit-like 

 opening; stipes short (5 to 8 mm.) and rather slender, 

 covered with imbricate, ovate-acuminate bracts; scales 

 almost free, ovate-lanceolate (about .". nun. long. 2.5 

 mm. broad). Interstaminate bracts rather few, irreg- 

 ularly shaped, ciliate and hairy at the lip. Stamens 

 glabrous, 2.5 to 4 mm. long, single or in clusters; fila- 

 ments rather slender; connective and anther cells as 

 in primary inflorescence. 



Receptacles of the pistillate inflorescence unusually 

 numerous on each twig, small, sessile. Scales velvety, the basal ones broadly 

 ovate-acuminate, the marginal ones narrower. Flowers small, concrescent at 

 the base. Free part of perianth thick, hairy outside and inside, usually divided 

 into 4 short, rounded lobes at the tip. Style thick and short (1.5 to 2 mm. long), 

 partly set with stiff minute bristles; stigmas 2 to 3 mm. long, twisted, papillose. 

 Fruiting receptacles very shallow. Achenia 15 to 25 on each receptacle, 

 deeply parted, scarcely sulcate; pulp orange red. (No specimens available.) 



Mexico: La Zacualpa, Chiapas, Cook, flowers and fruits, April, 1902 (U. S. 

 National Herbarium no. 408562; alcoholic materials of male and female in- 

 florescences; photographs 39(17, 3908. 3971, 4323). 



Explanation of Plates 26-28. — PL 2G, branchlets showing base of leaves and male 

 inflorescences. PL 27, branchlets showing inflorescences and terminal bracts. PI. 28, a, 

 fructiferous branchlet ; b, c, ripe fruits. All natural size. 



Castilla lactiflua comes very near to C. clastica, but differs from it by the flat 

 lobes of the primary male inflorescence, the flabellate complemental recep- 

 tacles, the fewer interstaminate bracts, and the shallow, flat, fruiting receptacles, 

 each with 15 to 25 seeds. 



Fig. 

 of 



48. — Floral details 

 Castilla lactiflua. 

 a-c, Stamens of pri- 

 mary inflorescence; d, 

 stamen of complemen 

 tal inflorescence; c, 

 cross section through 

 a pistillate flower, a-c, 

 Scale 3. 



