Vascular Plants of Williamson County

Phyllanthus abnormis var. abnormis [Euphorbiaceae]
drummond’s leaf–flower, sand leaf–flower

Phyllanthus abnormis Baill. var. abnormis, drummond’s leaf–flower, sand leaf–flower.  Annual, taprooted, several–stemmed at base, laternal shoots slender, to 22 cm tall; monoecious; shoots with only cauline leaves, 2–dimensional (plagiotropic) appearing like a compound leaf, with sleep movements, glabrous and glaucous.

Stems

Stems cylindric, < 1.5 mm diameter, green and photosynthetic dotted with tiny stomates.

Leaves

Leaves alternate distichous, simple, short–petiolate, with stipules; stipules 2, attached to projecting, persistent leaf bases, acuminate–ovate to triangular or lanceolate, symmetric or asymmetric, 1—1.5 mm long, whitish; petiole, 0.3—0.5 mm long, often tinged reddish; blade elliptic to oval, < 4—8.3 × 2.5—4.2 mm, rounded at base, entire, rounded at tip, pinnately veined with midrib raised on lower surface; upper surface uniform.

Inflorescence

Inflorescence cyme, axillary, initially of 1 pistillate and later 1 smaller staminate flower at base, nodding beneath leaves on short, descending axis (pedicel of pistillate flower), glabrous; bractlet subtending pedicel of pistillate flower, lanceolate, < 0.5 mm long, white; pedicel of pistillate flower at anthesis to 5 mm long increasing in fruit, aging thicker.

Staminate flower

Staminate flower bilateral, 0.6 mm across; perianth 4 opposite decussate, ovate, ± 0.5 × 0.35 mm, white and yellowish, sometimes minutely toothed; nectaries 4, at bases alternate with tepals; stamens 2, fused at center of flower; fused filaments 0.3 mm long, greenish; anthers dithecal, 0.2 mm long, yellowish, longitudinally dehiscent; pollen yellowish; pistil absent.

Pistillate flower

Pistillate flower 1.5 mm across; with enlarged, cuplike receptacle; sepals 3, ascending, ovate, ca. 0.7 0.5 mm, green with whitish margins; petals 3, ovate, ca. 0.5 × 0.3 mm increasing 2× in fruit, white with green midvein, in fruit spreading (not appressed); stamens absent; pistil 1; ovary superior, 6–lobed, ca. 0.6 × 0.6 mm, green, glabrous, 3–chambered, each chamber with 2 ovules attached to center; styles 3, 0.25 mm long, pale green, 2–branched at midpoint, the branches recurved.

Fruit

Fruit capsule, schizocarpic, loculicidal and septicidal, 6–seeded, oblate 6–lobed, 1.7 × 2.5 mm, green.

Seed

Seed 3–sided with rounded back and 2 flat sides, ca. 1.3 × 1 mm, brown, back finely sculptured with files of lengthwise cells.

A. C. Gibson