Morphology of Peixotoa.
a–d. Hairs representative of four types of vesture: a, velutinous; b, tomentose; c, “pubescent with T-shaped hairs”; d, sericeous. e. Hypothetical transition from pedunculate to sessile flower. f. Typical umbel subtended by a pair of leaves and two pairs of connate interpetiolar stipules (only one pair of stipules visible). g. “Subsidiary axis” located between the secondary axis and the leaf. h–k. Transition from 4-flowered (1-umbellate) terminal node to 12-flowered (3-umbellate) terminal node: h, all umbels 4-flowered, each umbel subtended by a pair of leaves and connate stipules; i, j, suppression of secondary axes accompanied by loss of leaves and stipules, the terminal node 12-flowered, the lateral nodes with a sessile umbel in each leaf axil; k, variation of condition in (j), with lateral umbels borne on secondary peduncles but not subtended by leaves and stipules. l. Floral diagram. First published by C. Anderson in Contr. Univ. Michigan Herb. 15: 4. 1982.