DANIEL & TRIPP: LOUTERIDIUM : TAXONOMY, BIOLOGY, AND CONSERVATION 63 
Table 3. Known months of flowering for species of Louteridium based on herbarium records. The total 
number of species flowering during each month and the total number of months that each species is in flower 
are shown. Species marked with pertain to section Tetrandrium and occur in dry forests. See text for 
discussion. 
Jan 
Feb 
Mar 
Apr 
May 
Jun 
Jul 
Aug 
Sep 
Oct 
Nov 
Dec 
Total/Species 
L. brevicalyx* 
X 
1 
L. chartaceum* 
X 
X 
X 
3 
L. costaricense 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
12 
L. dendropilosum* 
X 
X 
2 
L. donnell-smithii 
X 
X 
X 
X 
X 
X 
X 
X 
8 
L. koelzii* 
X 
X 
X 
3 
L. mexicanum 
X 
X 
X 
X 
X 
X 
X 
X 
X 
9 
L. parayi 
X 
X 
X 
X 
X 
X 
X 
X 
X 
9 
L. purpusii 
X 
X 
X 
X 
X 
X 
X 
X 
8 
L. rzedowskianum* 
X 
1 
L. tamaulipense 
X 
X 
X 
X 
X 
X 
6 
Total/Month 
7 
7 
8 
5 
5 
4 
2 
3 
5 
4 
5 
7 
Floral Life Cycle, Visitors, and Pollination. — In general for Louteridium, flowers 
begin to open (i.e., corolla lobes begin to unfurl and separate) in the late afternoon (full opening of 
individual flowers of L. dendropilosum took between 15 and 20 seconds during a series of field 
observations and up to 25 minutes in a cultivated plant of the species); most or all are fully open 
by darkness; anthers dehisce promptly and the widely spread stigma lobes are presumably recep¬ 
tive; visitation to flowers occurs soon after the onset of anthesis; and corollas dehisce and fall from 
the plant by mid- to late- morning of the following day. A corolla, from opening to dehiscing, on a 
cultivated plant of L. dendropilosum, persisted for about 16 hours. At least one variation on this 
general pattern was noted by Daniel (2010) for a dark colored floral form of L. donnell-smithii in 
Guatemala. If fertilization has been successful, the ovary begins to enlarge within a few days of 
corolla abscission. The full-sized capsule turns brown prior to maturity, and the mature capsule 
dehisces explosively, usually within about a month of pollination. 
Flowers are borne on relatively long pedicels in inflorescences that are generally located above 
the leaves. Pollen is located in the dehisced introrse anthers, which are situated several centimeters 
in front of and usually above the limb of the nototribic corollas. Like the stamens, the style extends 
in front of (and often slightly above) the corolla, with the stigma located near or up to ca. 1.5 cen¬ 
timeters in front of the anthers. Thus, the front or top of the head or the back of large floral visitors 
(e.g., bats and possibly hummingbirds) seeking nectar and approaching from the front of the flower 
could readily make contact with both the stigma (first) and anthers (second). 
Diurnal visitors to flowers include hummingbirds, which probe for nectar, and small bees 
or flies, which were only observed visiting anthers. Unidentified hummingbirds were observed 
visiting flowers of L. tamaulipense in the early morning (Richardson 1972), and a Cinnamon 
Hummingbird (. Amazilia rutila) was observed probing inside flowers of L. dendropilosum during 
the late afternoon (before dusk), following anthesis of at least some flowers during daylight hours. 
Nocturnal visitors include bats and moths (e.g., F. Archila, in litt.; see phenology section under 
L. donnell-smithii below). Characteristics of flowers associated with pollination by bats in the 
Neotropics have been summarized by numerous authors (e.g., Pijl 1957; Vogel 1969b; Proctor and 
Yeo 1972; Cruden et al. 1983; Baker et al., 1998; Willmer 2011; Abrol 2012). Plants of Louter¬ 
idium share most of these attributes, including: tree-like or epiphytic habit (most species), inflo- 
