PROCEEDINGS OF THE CALIFORNIA ACADEMY OF SCIENCES 
Series 4, Volume 65, 28 Sept. 2018, No. 2 
undetermined plant has four stamens. Other characteristics in co mm on with L. koelzii include erect 
to flexuose eglandular trichomes on the rachis, peduncles, and pedicels; ovate-elliptic calyx lobes, 
and externally glabrous corollas. It differs from specimens of L. koelzii studied herein by having 
pubescent young stems, shorter calyces (14-15 mm long, although the flowers are not fully 
mature), and longer (35^10 mm) capsules that are pubescent only at the apex. Disposition of this 
plant awaits further studies and/or collections. 
Additional specimens examined.— MEXICO. Jalisco: ca. 12-13 km SW of Pihuamo, 
R. McVaugh 26180 (MICH); 8 mi SW of Pihuamo, R. McVaugh & W. Koelz 1797 (MEXU, MICH, 
US). Michoacan: 15-16 km SE of Aserradero Dos Aguas, W of Aguililla [ca. 18°45’51.11”N, 
102°49’22.26’W], R. McVaugh 24740 (MICH). 
7. Louteridium mexicanum (Baill.) Standi., Contr. U.S. Natl. Herb. 23:1338. 1926. Neolinde- 
nia mexicana Baill., Bull. Mens. Soc. Linn. Paris 2:851. 1890. Type.— MEXICO. Veracruz or 
Chiapas: “forets humides de Zacualpan, Chiapas,” 11-1840 (fir), J. Linden s.n. (holotype: P!; 
isotypes: G!, K!). A collection number ( 1637) that is not on specimens at P and G, is on the spec¬ 
imen from Hooker’s herbarium at K. 
Louteridium conzattii Standi., Contr. U.S. Natl. Herb. 23:1338. 1926. Type.— MEXICO. 
Oaxaca: Distr. Tuxtepec, de Jalapa a La Raya, margen izquierda del Rio Grande, [ca. 
18°01’16.00”N, 096°34’25.98”W], 450 m, 3-XI-1919 (buds), C. Conzatti 3788 (holotype: US- 
1014038!; isotypes: MEXU! US-1014039!). 
Shrubs to trees to 12 m tall, terrestrial. Older (woody) stems subquadrate, irregularly striate- 
fissured, glabrous or glabrate; younger (herbaceous) stems quadrate to quadrate-sulcate, intemodes 
glabrous or with sparse flexuose to antrorse eglandular trichomes to 0.5 mm long, nodes glabrous 
or with some flexuose eglandular trichomes to 0.5 mm long. Leaves not all seasonally deciduous, 
evenly distributed on new growth, petiolate, petioles to 220 mm long, blades membranaceous, 
broadly ovate to ovate to ovate-elliptic to elliptic to broadly elliptic, 40-360 mm long, 21-170 mm 
wide, 1.3-2.9 x longer than wide, acuminate to acute-apiculate to caudate at apex, acute to round¬ 
ed to subcordate at base, adaxial surface glabrous, abaxial surface glabrous or pubescent along 
major veins with trichomes like those at nodes, margin ± entire to crenate. Inflorescence a termi¬ 
nal pedunculate (racemose thyrse to) thyrse to 390 mm long (including peduncle and excluding 
corollas), peduncle to 190 mm long, glabrous or pubescent like young stems, rachis glabrous or 
pubescent with flexuose to flexuose-antrorse eglandular trichomes 0.2-0.8 (-1) mm long (villous), 
trichomes sometimes restricted to nodes; dichasia modified by sympodial expansion into contract¬ 
ed to ± expanded unbranched or branched short-shoots to 25 (-46) mm long, opposite, subsessile 
to pedunculate, 3-many-flowered, to 120 mm long (excluding corollas), dichasial peduncles 1-22 
mm long, glabrous or villous. Bracts often caducous, sessile to petiolate, ovate to lance-elliptic to 
linear, 20-48 mm long, 2-16 mm wide (or the proximalmost pair sometimes foliose and larger), 
abaxially glabrous or pubescent with antrorsely appressed eglandular trichomes. Bracteoles and 
secondary bracteoles usually persistent, lance-ovate to lanceolate to linear-lanceolate, 10-25 mm 
long, 1-8 mm wide, abaxially glabrous or pubescent with a few antrorsely appressed eglandular 
trichomes to 0.5 mm long along midvein or pubescent with latter type trichomes over entire 
surface. Flowers pedicellate, pedicels to 85 mm long, glabrous or villous. Calyx 17-39 mm long, 
lobes appearing distinct or fused at base for 1-2 mm, heteromorphic, ± membranaceous, abaxially 
appearing glabrous although covered with minute sessile glands (glandular punctate; punctations 
< 0.05 mm in diameter) and posterior lobe sometimes sparsely villous along keel, posterior lobe 
conduplicate, ovate, 16-36 mm long, ± equaling to slightly longer than lateral lobes, 9-14 mm 
wide, acute to attenuate to subfalcate at apex, lateral lobes lunate, 16-32 mm long, 6-12 mm wide, 
